MO-MEGA Middle School Science- JK

Discuss the chemical composition of seawater

Salinity is a measure of the amount of dissolved salts in ocean water. It is defined in terms of conductivity. Salinity is influenced by the geologic formations in the area, with igneous formations leading to lower salinity and sedimentary formations leading to higher salinity. Dryer areas with greater rates of evaporation also have higher salt concentrations. Areas where freshwater mixes with ocean water have lower salt concentrations. Hydrogen and oxygen make up about 96.5% of sea water. The major constituents of the dissolved solids of seawater at an atomic level are chlorine (55.3%), sodium (30.8%), magnesium (3.7%), sulfur (2.6%), calcium (1.2%), and potassium (1.1%). The salinity of ocean water is fairly constant, ranging from 34.60 to 34.80 parts per thousand, which is 200 parts per million. Measuring variation on this small of a scale requires instruments that are accurate to about one part per million.

Define the following front-related weather phenomena; shearline, dry line, squall line, and tropical waves.

Shearline: this evolves from a stationary front that has gotten smaller. Wind direction shifts over a short distance. Dry line or dew point line: this separates two warm air masses of differing moisture content. At lower altitudes, the moist air mass wedges under the drier air. At higher altitudes, the dry air wedges under the moist air. This is a frequent occurrence in the Midwest and Canada, where the dry air of the Southwest and the moister air of the Gulf of Mexico meet. This can lead to extreme weather events, including tornadoes and thunderstorms. Squall line: severe thunderstorms can form at the front of or ahead of a cold front. A squall line can produce extreme weather in the form of heavy rain, hail, lightning, strong winds, tornadoes, and waterspouts. Tropical waves or easterly waves; These are atmospheric troughs or areas of low air pressure that travel westward in the tropics, causing clouds and thunderstorms.

Name and define three types of volcanoes.

Shield, cinder cone, and composite. A shield volcano is created by a long-term, relatively gentle eruption. This type of volcanic mountain is created by each progressive lava flow that occurs over time. A cinder cone volcano is created by explosive eruptions. Lava is spewed out of a vent into the air. As it falls to the ground, the lava cools into cinders and ash, which build up around the volcano in a cone shape. A composite volcano is a combination of the other two types of volcanoes. In this type, there are layers of lava flows and layers of ash and cinder.

Compare and contrast short and long-term weather forecasting.

Short and long-term weather forecasting is important because the day-to-day weather greatly affects humans and human activity. Severe weather and natural events can cause devastating harm to humans, property, and sources of livelihood, such as crops. The persistence method of forecasting can be used to create both short and long term forecasts in areas that change very little or change slowly. It assumes that the weather tomorrow will be similar to the weather today. Barometric pressure is measured because a change in air pressure can indicate the arrival of a cold front that could lead to precipitation. Long-term forecasts based on climate data are useful to help people prepare for seasonal changes and severe events such as hurricanes.

Define simple machines and list some examples

Simple machines include the inclined plane, lever, wheel and axle, and pulley. These simple machines have no internal source of energy. More complex or compound machines can be formed from them. Simple machines provide a force known as a mechanical advantage and make it easier to accomplish a task. The inclined plane enable a force less than the object's weight to be used to push an object to a greater height. A lever enables a multiplication of force. The wheel and axle allows for movement with less resistance. Single or double pulleys allows for easier direction of force. The wedge and screw are forms of the inclined plane. A wedge turns a smaller force working over a greater distance into a larger force. The screw is similar to an incline that is wrapped around a shaft.

Define single and double substitution reactions, and provide an equation and an example for each.

Single substitution, displacement, or replacement reactions are when one reactant is displaced by another to form the final product. Single substitution reactions can be cationic or anionic. When a piece of copper is placed into a solution of silver nitrate the solution turns blue. The copper appears to be replaced with a silvery-white material. When this reaction takes place, the copper dissolves and the silver in the silver nitrate solution precipitates (becomes a solid), resulting in copper nitrate and silver. Copper and silver have switched places in the nitrate. Double displacement, double replacement, substitution, metathesis, or ion exchange reactions are when ions or bonds are exchanged by two compounds to form different compounds. An example of this is that silver nitrate and sodium chloride form two different products when they react.

Discuss molarity, molality, and colligative properties.

The concentration of a solution is measured in terms of molarity. One molar (M) is equal to a quantity of moles of solute per liter of solution. Adding one mole of a substance to one liter of solution would most likely result in a molarity greater than one. The amount of substance should be measured into a small amount of solution, and then more solution should be added to reach a volume of one liter to ensure accuracy. Molality refers to the concentration of ratio of moles of solute per kilogram of solvent. Colligative properties refer to how a solvent acts when it becomes a solution. Colligative properties are determined by the number of solute molecules rather than their exact characteristics. Some examples of colligative properties are that a solution's osmotic pressure and boiling point increase and its melting point decreases when the amount of solute is increased. As the amount of solute is increased, vapor will decrease above the solution when it is composed of a solid, nonvolatile solute dissolved in a liquid.

Compare and contrast high and low pressure systems.

The concept of atmospheric pressure involves the idea that the air exerts a force. An imaginary column of air 1 square inch in size rising through the atmosphere would exert a force os 14.7 pounds per square inch (psi). Both temperature and altitude affect atmospheric pressure. Low and high pressure systems tend to want to equalize. Air tends to move from areas of high pressure to areas of low pressure. When air moves into a low pressure system, the air that was there gets pushed up, creating lower temperatures and pressures. Water vapor condenses and forms clouds and possibly rain and snow. A barometer is used to measure air pressure.

Explain the effect of temperature and pressure on solubility.

Solids tend to dissovle faster when the temperature is increased. Higher temperatures help break bonds through an increase in kinetic energy. Solubility tends to increase for solids being dissovled in water as the temperature approaches 100 degrees Celsius, but at higher temperatures ionic solutes tend to become less soluble. Gases tend to be less soluble at higher temperatures. When solutions are saturated at high temperatures, the solute will precipitate (return to solid form) and "fall out of the solution: as the solution cools. Melting points can be lowered by using a solvent such as salt on icy roads, which lowers the freeing point of ice. Adding salt to water when making ice cream also lowers the melting point of the water. A solution's melting point is usually lower than the melting point of hte solvent alone. Pressure has little effect on the solubility of liquid solutions. in fas solutions, an increase in pressure increases solubility, and vice versa.

List some properties of salts

Some properties of salts are that they are fomed from acid base reactions, are ionic compounds consisting of metallic and nonmetallic ions, dissociate in water, and are comprised of tightly bonded ions. Some common salts are sodium chloride, sodium bisulfate, potassium dichromate, and calcium chloride. Calcium chloride is used as a drying agent, and may be used to absorb moisture when freezing mixtures. Potassium nitrate is used to make fertilizer and in the manufacture of explosives. Sodium nitrate is also used in the making of fertilizer. Baking soda is a salt, as are Epsom salts, magnesium sulfate. Salt and water can react to form a base and an acid. THis is called hydrolysis reaction.

Discuss photosynthesis

The conversion of sunlight into energy in plant cells, and also occurs in some types of bacteria and protists. Carbon dioxide and water are converted into glucose during photosynthesis, and light is required during this process. Cyanobateria are thought to be the descendants of hte first organisms to use photosynthesis about 3.5 billion years ago. Photosynthesis is a form of cellular respiration. It occurs in chloroplasts that use thylakoids, which are structures in the membrane that contain light reaction chemicals. Chlorophyll is a pigment that absorbs light. During the process, water is used and oxygen is released. the equation for the chemical reaction that occurs during photosynthesis is 6h2O + 6CO2 -->c6H12O6+6O2. During photosynthesis, six molecules of water and six molecules of carbon dioxide react to form one molecule of sugar and six molecules of oxygen.

Summarize the characteristics of crystals

The crystalline structure of crystals is also known as a lattice. Crystal particles have symmetrical arrangements. Solidification may result in the formation of a single crystal or a group of crystals, which is known as polycrystalline structure. The symmetry of a crystal is used to determine its classification. Although they are organized, structured, and symmetrical, crystals are imperfect and can have defects. Some may also have a specific electrical properties. Crystal systems are grouped in accordance with their axial systems (there are three axes). The unique systems of crystals are cubic, hexagonal, rhombohedral, orthorhombic, monoclinic, and triclinic. Crystals in the cubic system are the most symmetric. The unit cell is the spatial arrangement of atoms. The spacing between unit cells is known as the lattice parameters. Salts form in cubic crystals. Common table salt (NaCl), for instance, forms a cubic lattice through ionic bonding. Rapid evaporation of a salt water solution results in small crystals, while slower evaporation leads to larger crystals.

Explain the phenomenon of sound.

Sound is a pressure disturbance that moves through a medium in the form of mechanical waves, which transfer energy from one particle to the next. Sound requires a medium to travel through, such as air, water, or other matter since it is the vibrations that transfer energy to adjacent particles, not the actual movement of particles over a great distance. Sound is transferred through the movement of atomic particles, which can be atoms or molecules. Wave of sound energy move outward in all directions from teh source. Sound waves consist of compressions (particles are forced together) and rarefactions (particles move farther apart and their density decreases). A wavelength consists of one compression and one rarefaction. One compression to another compression. Different sounds have different wavelengths. Sound is a form of kinetic energy.

Discuss the electromagnetic spectrum

The electromagnetic spectrum is defined by frequency and wavelength. Frequency is typically measured in hertz and wavelength is usually measured in meters. Because light travels at a fairly constant speed, frequency is inversely proportional to wavelength, a relationship expressed by a formula that I can't type here. Frequency multiplied by wavelength equals the speed of the wave; for electromagnetic waves, this is the speed of light, with some variance for the medium in which it is traveling. Electromagnetic waves include (from largest to smallest wavelength) radio waves, microwaves, infrared radiation (radiant heat), visible light, ultraviolet radiation, x-rays, and gamma rays. The energy of electromagnetic waves is carried in packets that have a magnitude inversely proportional to the wavelength. Radio waves have a range of wavelengths from about 10^-3 to 10^5 meters, while their frequencies range from about 10^3 to 10^11 HZ.

Describe some piloted space missions.

The Soviet space program successfully completed the first space flight by orbiting Yuri Gagarin in 1961 on Vostok 1. His orbit lasted 1 hour, 48 minutes. Later in 1961, the US completed its first piloted space flight by launching Alan Shepard into space in the Mercury-Redstone 3. This space mission was suborbital. The first woman in space was Valentina Tereshkova, who orbited the Earth 48 times aboard Vostok 6 in 1963. The first space flight with more than one person and also the first that didn't involve space suits took place on the Voskhod in 1964. The first person on the Moon was American Neil Armstrong. in 1969, he traveled to the Moon on Apollo 11, which was the 11th manned space flight completed in the Apollo program, which was conducted from 1968 to 1972. In 2003, Yang Liwei became the first person from China to go into space. He traveled onboard the Shenzhou 5. The Space Shuttle Orbiter has included piloted space shuttles from 1981 until the present. The program was suspended after two space shuttle disasters: Challenger in 1986 and Columbia in 2003.

Explain how energy is generated by the Sun

The Sun's energy is produced by nuclear fusion reactions. Each second, about 700,000,000 tons of hydrogen are converted (or fused) to about 695,000,000 tons of helium and 5,000,000 tons of energy in the form of gamma rays. In nuclear fusion, four hydrogen nuclei are fused into one helium nucleus, resulting in the release of energy. In the Sun, the energy proceeds towards the surface and is absorbed and re-emitted at lower and lower temperatures. Energy is mostly in the form of visible light when it reaches the surface. It is estimated that the Sun has used dup about half of the hydrogen at its core since its birth. It is expected to radiate in this fashion for another 5 billion years. Eventually, it will deplete its hydrogen fuel, grow brighter, expand to about 260 times its diameter, and become a red giant. The outer layers will ablate and a become dense white dwarf the size of Earth.

Define stratigraphy and discuss its subfields

Stratigraphy is a branch of geology that involves the study of rock layers and layering. Sedimentary rocks are the primary focus of stratigraphy. Subfields include lithostratigraphy, which is the study of the fossils evidence in rock layers. Magnetostratigraphy is the study of changes in detrital remnant magnetism (DRM), which is used to measure the polarity of Earth's magnetic field at the time of a stratum was deposited. Chronostratigraphy focuses on the relative dating of rock strata based on the time of rock formation. Unconformity refers to missing layers of rock.

Identify the causes of ocean currents

Surface currents are caused by winds. Subsurface currents, which occur deep beneath the ocean's surface are caused by land masses and the Earth's rotation. The density of ocean water can also affect currents. Sea water with a higher salinity is denser than seawater with a lower salinity. Water from denser areas flows to areas with water that is less dense. Currents are classified by temperature. Colder polar sea water flows south towards warmer water, forming cold currents. Warm water currents swirl around the basin and equator. In turn, heat lost and gained by the ocean creates winds. Ocean currents play a significant role in transferring this heat toward the poles, which aids in the development of many types of weather phenomena.

Discuss the occurrence and causes of local atmospheric variations.

Terrain affects several local atmospheric conditions, including temperature, wind speed, and wind direction. When there are land forms, heating of the ground can be greater than the heating of the surrounding air than it would be at the same altitude above sea level. This creates a thermal low in the region and amplifies any existing thermal lows. It also changes the wind circulation. Terrain such as hills and valleys increase friction between the air and the land, which disturbs the air flow. THis physical block deflects the wind, and the resulting air flow is called a barrier jet. Just as the heating of the land and air affect sea and land breezes along the coast, rugged terrain affects the wind circulation between mountains and valleys.

Discuss the Bergeron system of classifying air masses according to their temperature, moisture content and source areas.

The Bergeron classification system uses three sets of letters to identify the following characteristics of air masses: moisture content, thermal characteristics from where they originated, and the stability of the atmosphere. The first, moisture content, uses the following letters: "C" represents the dry continental air masses and "m" stands for the moist maritime air masses. The second set of abbreviations are as follows; "T" indicates the air mass is tropical in origin; "P" indicates the air mass is polar in origin; "A" indicates the air mass is Antarctic in origin; "M" stands for monsoon; "E" indicates the air mass is equatorial in origin; and "S" is used to represent superior air, which is dry air formed by a downward motion. The last set of symbols provides an indicator of the stability of the mass. "K" indicates the mass is colder than the ground below it, while "w" indicates that mass is warmer than the ground. For example, cP is a continental polar air mass, while cPk is a polar air mass blowing over the Gulf Stream, which is warmer than the mass.

Describe the Cenozoic era in context of the geologic time scale and explain why it was important.

The Cenozoic era began about 65.5 million years ago and continues to the present. It is marked by the Cretaceous-Tertiary extinction event (extinction of the dinosaurs as well as many invertebrates and plants). The Cenozoic era is further divided into the Paleogene, Neogene, and Quaternary periods. During the Cenozoic era, Pangaea continued to drift, and the plates eventually moved into their present positions. The Pleistocene Ice Age, also known as Quaternary glaciation or the current ice age began about 2.58 million years ago and includes the glaciation occurring today. Mammals continued to evolve and other plants and animals came into existence during this era. The fossil record includes the ancestors of the horse, rhinoceros, and camel. It also includes the first dogs and cats and the first human like creatures. The first humans appeared less that 200,000 years ago.

Explain the Doppler Effect

The Doppler Effect refers to the effect the relative motion of the source of the wave and the location of the observer has on waves. The Doppler Effect is easily observable in sound waves. What a person hears when a train approaches or a car honking as its horn passes by are examples of the Doppler Effect. The pitch of the sound is different not because the emitted frequency has changed, but because the received frequency has changed. The frequency is higher (as is the pitch) as the train approaches, the same emitted just as it passes, and lower as the train moves away. This is because the wavelength changes. The Doppler Effect can occur when an observer is stationary, and can also occur when two trains approach and pass each other. Electromagnetic waves are also affected in this manner. The motion of the medium can also affect the wave. For waves that do not travel in a medium, such as light waves, it is the difference in velocity that determines the outcome.

Define and discuss the shoreline and coastal processes

The area where land meets the sea is called the shoreline. This marks the average position of the ocean. Longshore currents create longshore drift or transport (also called beach drift). This is when ocean waves move toward a beach at an angle, which moves water along the coast. Sediment is eroded from some areas and deposited in others, In this way, it is moved along the beach. Rip currents are strong, fast currents that occur when part of longshore current moves away from the beach. Hard, man-made structures built perpendicular to the beach tend to trap sand on the up-current side. Erosion occurs on the down-current side. Features formed by the sediment deposited by waves include spits, baymouth bars, tombolos, barrier islands, and buildups. Sand is composed of weather-resistant, granular materials like quartz and orthoclase. In some location, it is composed of rock and basalt.

Discuss the Oort Cloud, the asteroid belt, and the Kuiper Belt.

The asteroid belt is between Mars and Jupiter. The many objects contained within are composed of rock and metal similar to those found on the terrestrial planets. The Kuiper Belt is beyond Neptune's orbit, but the influence of the gas giants may cause objects from the Kuiper Belt to cross Neptune's orbit. Objects in the Kuiper Belt are still being discovered. They are thought to be composed of frozen forms of water, ammonia, and methane, and may be the source of short-period comets. It is estimated that there are 35,000 Kuiper Belt objects greater than 100 km in diameter and perhaps 100 million objects about 20 km in diameter. There is also a hypothetical Oort Cloud that may exist far beyond the Kuiper Belt and act as a source for long-period comets.

Discuss the composition of the Earth's atmosphere and name its five main layers

The atmosphere consists of 78% nitrogen, 21% oxygen, and 1% argon. It also includes traces of water vapor, carbon dioxide and other gases, dust particles, and chemicals from Earth. The atmosphere becomes thinner the farther it is from Earth's surface. It becomes difficult to breathe at about 3 km above sea level. The atmosphere gradually fades into space. The lowest layer of the atmosphere is called the troposphere. Its thickness varies at the poles and the equator, varying from about 7 to 17 km. This is where most weather occurs. The stratosphere is next, and continues to an elevation of about 51 km. The mesosphere extends from the stratosphere to and elevation of about 81 km. It is the coldest layer and is where meteors tend to ablate. The next layer is the thermosphere. It is where the International Space Station orbits. The exosphere is the outermost layer, extends to 10,000 km, and mainly consists of hydrogen and helium.

Explain the concept of the mole and discuss Avogadro's number

The atomic mass unit (amu) is the smallest unit of mass, and is equal to 1/12 of the mass of the carbon isotope carbon-12. A mole (mol) is a measurement of molecular weight that is equal to the molecule's amu in grams. For example, carbon has an amu of 12, so a mole of carbon weighs 12 grams. One mole is equal to about 6.0221415 x 10^23 elementary entities, which are usually atoms or molecules. This amount is also known as Avogadro constant or Avogadro's number (NA). Another way to say this is that one mole of a substance is the same as one Avogadro's number of that substance. The charge on one mole of electrons is referred to as a Faraday.

Define and discuss electric charges as they relate to atomic structure.

The attractive force between the electrons and the nucleus is called the electric force. A positive (+) charge or a negative (-) charge creates a field of sorts in the empty space around it, which is known as an electric field. The direction of a positive charge is away from it and the direction of a negative charge is towards it. An electron within the force of the field is pulled towards a positive charge because an electron has a negative charge. A particle with a positive charge is pushed away, or repelled by another positive charge. Like charges repel each other and opposite charges attract. Lines of force show the paths of charges. Electric force between two objects is directly proportional to the product of the charge magnitudes and inversely proportional to the square of the distance between teh two objects. Electric charge is measured with teh unit Coulomb (C). It is the amount of charge moved in one second by a steady current of one ampere (1C = 1A x 1s)

Define and discuss mutation and the DNA level

A DNA mutation occurs when the normal gene sequence is altered. Mutations can happen when DNA is damaged as a result of environmental factors, such as chemicals, radiation, or ultraviolet rays from the sun. It can aslo happen when errors are made during DNA replication. The phosphate-sugar side rail of DNA can be damaged if the bonds between oxygen and phosphate groups are disassociated. Translocation happens when the broken bonds attempt to bond with other DNA. This repair can cause a mutation. The nucleotide itself cna be altered. A C, for example, might look like a T. During replication, the damaged C is replicated as a T and paired with a G, which is incorrect base pairing. Another way mutations can occur is if an error is made by the DNA plymerase while replicating a base. This happens about once for every 100,000,000 bases. A repair protein proofreads the code, however, so the mistake is usually repaired.

Explain what a buffer is

A buffer is a solution whose pH remains relatively constant when a small amount of an acid or a base is added. It is usually made of a weak acid and its conjugate base (proton receiver) or one of its soluble salts. It can also be made of a weak base and its conjugate acid (proton donator) or one of its salts. A constant pH is necessary in living cells because some living things can only live within a certain pH range. If that pH changes, the cells could die. Blood is and example of a buffer. A pKa is a measure of acid dissociation or the acid dissociation constant. Buffer solutions can help keep enzymes at the correct pH they are also used in the fermentation process, in dyeing fabrics and in the calibration of pH meters. An example of a buffer is HC2H3O, a weak acid.

Define the four main frontal systems; cold, warm, stationary, and occluded.

A cold front is a mass of cold air, usually fast moving and dense, that moves into a warm air front, producing clouds. This often produces a temperature drop and rain, hail, thunder, and lightning. A warm front is pushed up by a fast moving cold front. It is often associated with high wispy clouds, such as cirrus and cirrostratus clouds. A stationary front forms when a warm and cold front meet, but neither is strong enough to move the other. Winds blowing parallel to the fronts keep the front stationary. The front may remain in the same place for days until the wind direction changes and both fronts become a single warm or cold front. In other cases, the entire front dissipates. An occluded front is when a cold front pushes into a warm front. The warm air rises and the two masses of cool air join. These types of fronts often occur in areas of low atmospheric pressure.

Discuss comets

A comet consists of frozen gases and rocky and metallic materials. Comets are usually small and typically have long tails. A comet's tail is made of ionized gases. It points away from the Sun and follows the comet as it approaches the Sun. The tail precedes the head as the comet moves away from the Sun. It points away from the Sun. It is believed that as many as 100 billion comets exist. About 12 new ones are discovered each year. Their orbits are elliptical, not round. Some scientists theorize that short-period comets originate from the Kuiper Belt and long-period comets originate from the Oort Cloud, which is thought to be 100,000 AU away. Comets orbit the Sun in time periods varying from a few years to hundreds of thousands of years. A well-known comet, Halley's Comet, has an orbit of 76 years. It is 80 percent water, and consists of frozen water, carbon dioxide (dry ice), ammonia, and methane.

Compare geosynchronous and geostationary orbits

A geosynchronous orbit around the Earth has an orbital period matching the Earth's sidereal rotation period. Sidereal rotation is based on the position of a fixed star, not the Sun, so a sidereal day is slightly shorter than a 24-hour solar day. A satellite in a geosynchronous orbit appears in the same place in the sky at the same time each day. Technically, any object with an orbit time period equal to the Earth's rotational period is geosynchronous. A geostationary orbit is a geosynchronous orbit that is circular and at zero inclination, which means the object is located directly above the equator. Geostationary orbits are useful for communications satellites because they are fixed in the same spot relative to the Earth. A semisynchronous orbit has an orbital period of half a sidereal day.

Discuss the basics of a magnet, including composition, poles, and permanence.

A magnet is a piece of metal, such as iron, steel, or magnetite (lodestone) that can affect another substance within its field of force that has like characteristics. Magnets can either attract or repel other substances. Magnets have two poles: north and south. Like poles repel and opposite poles attract. The magnetic field is a set of invisible lines representing the paths of attraction and repulsion. Magnetism can occur naturally,k or ferromagnetic materials can be magnetized. Certain matter that is magnetized can retain its magnetic properties indefinitely and become a permanent magnet. Other matter can lose its magnetic properties. For example, an iron nail can be temporarily magnetized by stroking it repeatedly in the same direction using one pole of another magnet. Once magnetized, it can attract or repel other magnetically inclined materials, such as paper clips. Dropping the anil repeatedly will cause it to lose its charge.

Discuss magnetic fields and current and magnetic domains.

A magnetic field can be formed not only by a magnetic material, but also by electric current flowing through a wire. When a coiled wire is attached to the two ends of a battery, for example, an electromagnet can be formed by inserting a ferromagnetic material such as an iron bar within the coil. When electric current flows through the wire, the bar becomes the magnet. If there is no current, the magnetism is lost. A magnetic domain occurs when the magnetic fields of atoms are grouped and aligned. These groups form what can be thought of as miniature magnets within a material. This is what happens when an object like an iron nail is temporarily magnetized. Prior to magnetization, the organization of atoms and their various polarities are somewhat random with respect to where the north and south poles are pointing. After magnetization, a significant percentage of the poles are lined up in one direction, which is what causes the magnetic force exerted by the material.

Discuss meteors, meteoroids, and meteorites

A meteoroid is the name for a rock from space before it enters the Earth's atmosphere. Most meteoroids burn up in the atmosphere before reaching altitudes of 80 km. A meteor is the streak of light from a meteoroid in the Earth's atmosphere, and is also known as a shooting star. Meter showers are associated with comets, happen when the Earth passes through the debris of a comet, and are associated with a higher than normal number of meteors. Meteorites are rocks that reach the Earth's surface from space. Fireballs are very bright meteors with trails that can last as long as 30 minutes. A bolide is a fireball that burns up when it enters Earth's atmosphere. There are many types of meteorites, and they are known to be composed of various materials. Iron meteorites consist of iron and nickel with a criss-cross, or Widmanstatten, internal metallic crystalline structure. Stony iron meteorites are composed of iron, nickel, and silicate and also contain iron and nickel.

Brielfy define mixtures, suspensions, colloids, emulsions, and foams.

A mixture is a combination of two or more substances that are not bonded. Suspensions are mixtures of heterogeneous materials. Particles are usually larger than those found in true solutions. Dirt mixed vigorously with water is an example of a suspension. The dirt is temporarily suspended in water, but the two separate once the mixing is ceased. A mixture of large particles is called colloidal suspension. The particles are termed dispersants and the dispersing medium is similar to the solvent in a solution. Sol refers to a liquid or a solid that also ahs solids dispersed through it, such as milk or gelatin. An aerosol spray is a colloid suspension of gas and the solid or liquid being dispersed. An emulsion refers to a liquid or a solid that has a liquid dispersed through it. A soam is a liquid that has a gas dispersed through it.

Discuss the birth of a star

A nebula is a cloud of dust an gas that is composed primarily of hydrogen (97%) and helium (3%). Gravity causes parts of the nebula ot clump together. This accretion continues adding atoms to the center of an unstable protostar. Equilibrium between gravity pulling atoms and gas pressure pushing heat and light away from the center is achieved. A star dies when it is no longer able to maintain equilibrium. A protostar may never become a star if it does not reach a critical core temperature. It may become a brown dwarf or a gas giant instead. If nuclear fusion of hydrogen into helium begins, a star is born. The "main sequence" of a star's life involves nuclear fusion reactions. During this time, the star contracts over billions of years to compensate for the heat and light energy lost. In the star's core, temperature, density, and pressure increase as the star contracts and the cycle continues.

Discuss the techniques of relative and absolute time

A numerical, or "absolute", age is a specific number of years, such as 150 million years ago. A "relative" age refers to a time range, such as the Mesozoic era. It is used to determine whether one rock formation is older or younger than another formation. Radioactive dating is a form of absolute dating and stratigraphy is a form of relative dating. Radioactive dating techniques have provided the most information about the absolute age of rocks and other geological features. Together, geochronologists have created a geologic time scale. Biostratigraphy uses plant and animal fossils within rock to determine its relative age.

Discuss theories related to the formation of the solar system

A planetary system consists of various non-stellar objects orbiting a star, such as planets, dwarf planets, moons, asteroids, meteoroids, comets, and cosmic dust. The Sun, together with its planetary system, which includes Earth, is known as the solar system. The theory of how the solar system was created is that it started with the collapse of a cloud of interstellar gas and dust, which formed the solar nebula. This collapse is believed to have occurred because the cloud was disturbed. As it collapsed, it heated up and compressed at the center, forming a flatter protoplanetary disk with a protostar at the center. Planets formed as a result of accretion from the disk. Gas cooled and condensed into tiny particles of rock, metal, and ice. These particles collided and formed into larger particles, and then into objects the size of small asteroids. Eventually, some became large enough to have significant gravity.

Discuss the following time measurements of the Earth: sidereal days and solar days.

A sidereal day is four minutes shorter than a solar day. A solar day is the time it takes the Earth to complete on revolution and face the Sun again. From noon to noon is 24 hours. A sidereal day is measured against a distant "fixed" star. As the Earth completes one rotation, it has also completed part of its revolution around the Sun, so it completes a sidereal rotation in reference to the fixed star before it completes a solar rotation. The Sun travels along the ecliptic in 365.25 days. This can be tracked day after day before dawn. After one year, the stars appear back in their original positions. As a result, different constellations are viewable at different times of the year. Sidereal years are slightly longer than tropical years. The difference is caused by the precession of the equinoxes. A calendar based on the sidereal year will be out of sync with the seasons at a rate of about one day every 71 years.

Discuss solutions

A solution is a homogeneous mixture. A mixture is two or more different substances that are mixed together, but not combined chemically. Homogenous mixtures are those that are uniform in their composition. Solutions consist of a solute (the substance that is dissolved) and a solvent (the substance that does the dissolving). An example is sugar water. The solvent is the water and the solute is the sugar. The intermolecular attraction between the solvent and the solute is called solvation. Hydration refers to solutions in which water is the solvent. Solutions are formed when the forces of the molecules of the solute and the solvent are as strong as the individual molecular forces of the solute and the solvent. An example is salt. It dissolves in water to create a solution. The Na+ and the Cl- ions in salt interact with the molecules of water and vise versa to overcome the individual molecular forces of the solute and the solvent.

List a few common solutions, differentiate between dilute and concentrated solutions, and list some additional properties of solutions.

A syrup is a solution of water and sugar. A brine is a solution of table salt, or sodium chloride and water. A saline solution is a sterilized concentration of sodium chloride in water. A seltzer is a solution of carbon dioxide in water. The term dilute is used when there is less solute. Adding more solvent is known as diluting a solution, as is removing a portion of the solute. Concentrated is the term used when there is more solute. Adding more solute makes a solution more concentrated, as does removing a portion of the solvent. Properties of solutions include: they have a maximum particle size of one nm, they do not separate when allowed to stand or when poured through a fiber filter, they are clear and do not scatter light, and their boiling points increase while their melting points decrease when the amount of solute is increased.

Describe weather fronts and weather maps

A weather front is the area between two differing masses of air that affects weather. Frontal movements are influenced by the jet stream and other high winds. Movements are determined by the type of front. Cold fronts move up to twice as fast as warm ones. It is in the turbulent frontal area that commonplace and dramatic weather events take place. This area also creates temperature changes. Weather phenomena include rain, thunderstorms, high winds, tornadoes, cloudiness, clear skies, and hurricanes. Different fronts can be plotted on weather maps using a set of designated symbols. Surface weather maps can also include symbols representing clouds, rain, temperature, air pressure and fair weather.

Define precipitation and discuss the different types.

After clouds reach the dew point, precipitation occurs. Precipitation can take the form of a liquid or a solid. It is known by many names, including rain, snow, ice, dew, and frost. Liquid forms a precipitation include rain and drizzle. Rain or drizzle that freezes on contact is known as freezing rain or freezing drizzle. Solid or frozen forms of precipitation include snow, ice needles or diamond dust, sleet or ice pellets, hail, and graupel or snow pellets. Vigra is a form of precipitation that evaporates before reaching the ground. It usually looks like sheets or shafts falling from a cloud. The amount of rainfall is measured with a rain gauge. Intensity can be measured according to how fast precipitation is falling or by how severely it limits visibility. Precipitation plays a major role in the water cycle since it is responsible for depositing much of the Earth's fresh water.

Define the temperature characteristics of air masses and describe their interaction with weather fronts.

Air masses are large volumes of air in the troposphere of the Earth. They are categorized by their temperature and by the amount of water vapor they contain. Arctic and Antarctic air masses are cold, polar air masses are cool, and tropical and equatorial air masses are hot. Other types of air masses include maritime and monsoon, both of which are moist and unstable. There are also continental and superior air masses, which are dry. A weather front separates two masses of air of different densities. It is the principal cause of meteorological phenomena. Air masses are quickly and easily affected by the land they are above. They can have certain characteristics, and then develop new ones when they get blown over a different area.

Define amplitude, rest position, crest, trough, and wavelength as they relate to waves

Amplitude is the maximum amount of displacement of a particle in a medium from its rest postition, and corresponds to the amount of energy carried by the wave. High-energy waves have greateer amplitudes; low energy waves have lesser amplitudes. Amplitude is a measure of a wave's strength. Rest position, also called equilibrium, is the point at which there is neither positive nor negative displacement. Crest, also called the peak, is the point at which a wave's positive or upward displacement from the rest position is at its maximum. Trough, also called a valley, is the point at which a wave's negative or downward displacement from the rest position is at its maximum. A wavelength is one complete wave cycle. It could be measured from crest to crest, trough to trough, rest position to rest position, or any point of a wave to the corresponding point on the next wave.

Define the following large units of distance: astronomical unit, light year, and parsec.

An astronomical unit, also known asAU, is a widely used measurement in astronomy. One AU is equal to the distance from the Earth to the Sun, which is 150 million km, or 93 million miles. These distances can also be expressed as 149.60 x 10^9 m or 92.956 x 10^6 mi. A light year is the distance that light travels in a vacuum in one year. A light year is equal to about 10 trillion km, or 64,341 AU, and is used to measure large astronomical units. Also used for measuring large distances is the parsec, which is the preferred unit since it is better suited for recording observational data. A parsec is the parallax of one arcsecond, and is about 31 trillion km (abot 19 trillion miles), or about 3.26 light years. It is used to calculate distances by triangulation. The AU distance from the Earth to the Sun is used to form the side of a right triangle.

Explain how an electric motor works.

An electric motor converts electric energy into mechanical energy. Energy can be provided by and AC or DC source. The power provided has many practical applications. The basic premise of a motor is that the electric current passing through a wire or coil creates a magnetic field that opposes the poles of a permanent magnet. The repelling forces between one pole of the electromagnet and the opposing pole of the fixed magnet cause the coil to move about 1/2 a turn. As it approaches the pole of like attraction, the coil would normally stop moving. In a motor however, the current is reversed at this time, which reverses the poles and again forces rotation. in a DC motor, a switch or commuter can be used to reverse the charge. In an AC motor, the charge alternates on its own. The coil is attached to a shaft that is rotated, which provides the mechanical energy necessary to do work.

Compare an electric motor and a generator, and then explain why a bird on a wire does not get electrocuted.

An electrical generator is the opposite of a motor in that it transforms magnetic force into electrical energy. Like a motor, however, it uses an electromagnetic field and a permanent magnet to achieve electromagnetic induction. Generators do not create electricity, but rather convert mechanical energy into electric energy. Smaller gas generators are used as backup or primary power sources of electricity for equipment, homes, and other small-scale applications. larger generators may use mechanical energy from many different sources, including water, steam, wind, compressed air, or even a hand crank. The current does not flow through the bird because it and the wire have the same electric potential. therefore, there is no reason for the current to move from the wire to the bird. If the bird touched something else in addition to the wire and became grounded, the electrons would flow through the bird and electrocute it.

List some methods for balancing equations.

An unbalanced equation is one that does not follow the law of conservation of mass, which states that matter can only be changed, not created. If an equation is unbalanced, the number of atoms indicated by the stoichiometric coefficients on each side of the arrow will not be equal. Start by writing the formulas for each species in the reaction. Count the atoms on each side and determine if the number is equal. Coefficients must be whole numbers. Fractional amounts, such as half a molecule are not possible. Equations can be balanced by multiplying the coefficients by a constant that will produce the smallest possible whole number coefficient.

Discuss Archimedes's principle

Archimedes's principle states that a buoyant (upward) force on a submerged object is equal to the weight of the liquid displaced by the object. Water has a density of one gram per cubic centimeter. Anything that floats in water has a lower effective density, and anything that sinks has a higher effective density. This principle of buoyancy can also be used to calculate the volume of an irregularly shaped object. The mass of the object(m) minus its apparent mass in the water divided by the density of water, gives the object's volume.

Compare and contrast series and parallel circuits.

As they relate to electric current, series circuits are circuits in which there is only one path through which electrons can flow. If a load in this type of circuit is removed, disabled, or switched off, the circuit is open and electricity does not flow. A parallel circuit is one in which there is more than one path through which electrons can travel. In a series circuit, the same current flows through all component. In a parallel circuit, on the other hand, the same voltage exists across all parallel paths, though the current may be vastly different among them. An example of a series circuit is a string of old-fashioned christmas tree lights. if one bulb breaks or comes loose, the entire string iwll not work.

Define astronomy

Astronomy is the scientific study of celestial objects and their positions, movements, and structures. Celestial does not refer to eh Earth in particular, but does include its motions as it moves through space. Other objects include the Sun, moon, planets, satellites, asteroids, meteors, comets, stars, galaxies, and the universe, and other space phenomena. THe term astronomy has its roots in the Greek words "astro" and "nomos" which means "laws of the stars"

Discuss the periodic trends in relation to atomic and ionic radii, electronegativity, ionization energy and electron affinity, and physical properties such as melting points.

Atomic radii will decrease from left to right across a period (row) on the periodic table. In a group (column), there is an increase in the atomic radii of elements from top to bottom. Ionic radii will be smaller than the atomic radii for metals, but the opposite is true for non-metals. From left to right, electronegativity, or an atom's likeliness of taking another atom's electrons, increases. In a group, electronegativity decreases from top to bottom. Ionization energy or the amount of energy needed to get rid of an atom's outermost electron, increases across a period and decreases down a group. Electron affinity will become more negative across a period but will not change much within a group. The melting point decreases from top to bottom in the metal groups and increases from top to bottom in the non-metal groups.

Discuss binary compounds

Binary compounds refer to compounds that contain only two elements. They can be ionic or covalent. Binary ionic compounds are formed by cations (metallic positive ions) and anions (nonmetal negative ions). Ionic compounds are not molecules. THe suffix "ide" is used if there is on anion, as in the case of cuprous oxide, for example. Another example is that fluorine is an element, while fluoride is a negative ion of fluorine. The binary compound barium fluoride would be written as BaF2. This is because one barium ion has a charge of +2 and one fluoride ion has a charge of -1, so it would take two fluoride ions to balance out the one barium ion. If there is no charge symbol, it is assumed that the charge is 1. The suffixes "ate" or "ite" are used when there is more than one anion, as in the case of mercurous nitrate, for example. A ternary compound is one formed of three elements.

Describe the Mesozoic era in the context of the geologic time scale and explain why it was important.

The Mesozoic era is known as the Age of the Dinosaurs. It is also the era during which the dinosaurs became extinct. The fossil record also shows the appearance of mammals and birds. Trees that existed included gymnosperms, which have uncovered seeds and are mostly cone bearing and angiosperms, which have covered seeds and are flowering plants. The angiosperm group is currently the dominant plant group. It was also during this era that the supercontinent Pangaea divided into the continental pieces that exist today. During the Cretaceous period, sea levels rose until one-third of the Earth's present land mass was underwater, and then receded. This period created huge marine deposits and chalk. The extinction of the dinosaurs happened about 65 million years ago, and was believed to have been triggered by the impact of an asteroid.

Define calorimeter, endergonic, exergonic, Gibbs free energy, and enthalpy.

Calorimeter: this is a device that measures heat. It may be used to measure the heat generated by a chemical reaction, state change, or solution formation. When using a calorimeter and the medium in which the reaction took place (not the reaction itself) gains heat, it would indicate an exothermic reaction. The heat left the reaction and entered the medium and the difference in heat was what was measured with the calorimeter. Endergonic: this is a chemical reaction in which it takes more energy to instigate the reaction than is produced by it. Exergonic: this is a chemical reaction in which the net amount of Gibbs free energy is less than zero. Gibbs free energy: this value is similar to the available energy or maximum work of a closed system. Enthalpy: this is a measure of heat content in a system. It is usually assumed that the system is closed and the pressure is constant. Enthalpy is represented by the symbol H. THe heat of a reaction is the difference between the heat stored in the reactants and in the products.

Explain nutritional requirements in animals and humans

Carbohydrates are the primary source of energy as they can be easily converted to glucose. Fats (oils or lipids) are usually not very water soluble, and vitamins A,D, E, and K are fat soluble. Fats are needed to help process these vitamins and can also store energy. Fats have the highest calorie value per gram (9,000 calories) Dietary fiber, or roughage, helps the excretory system. In humans, fiber can help regulate blood sugar levels, reduce heart disease, help food pass through the digestive system, and add bulk. Dietary minerals are chemical elements that are involved with biochemical functions in the body. Proteins consist of amino acids. Proteins are broken down in the body into amino acids that are used for protein biosynthesis of fuel. Vitamins are compounds that are not made by the body, but obtained through the diet. Water is necessary to prevent dehydration since water is lost through the excretory system and perspiration.

Explain the effects of catalysts on reactions and define the Maxwell-Boltzmann distribution.

Catalysts, substances that help change the rate of reaction without changing their form, can increase reaction rate by decreasing hte number of steps it takes to form products. The mass of the catalyst should be the same at the beginning of the reaction as it is at the end. The activation energy is the minimum amount required to get a reaction started. Activation energy causes particles to collide with sufficient energy to start the reaction. A catalyst enables more particles to react, which lowers the activation energy. Examples of catalysts in reactions are manganese oxide in the decomposition of hydrogen peroxide, iron in the manufacture of ammonia using the Haber process, and concentrate of sulfuric acid in the nitration of benzene. Maxwell-Boltzmann distribution: this refers to a graph or plot showing the energies or speeds of particles or gas molecules in a system

Explain how conduction can produce charges and dscribe the law of conservation of charge.

Charging by conduction is similar to charging by induction, except that the material transferring the charge actually touches the material receiving the charge. A negatively or positively charged object is touched to an object wit ha neutral charge. Electrons will either flow into or out of the neutral object and it will become charged. Insulators cannot be used to conduct charges. Charging by conduction can also be called charging by contact. The law of conservation of charge states that the total number of units before and after a charging process remains the same. No electrons have been created. They have just been moved around. The removal of a charge on an object by conduction is called grounding.

Explain how to read chemical equations

Chemical equations describe chemical reactions. THe reactants are on the left side before the arrow and the products are on the right side after the arrow. The arrow indicates the reaction or change. THe coefficient, or stoichiometric coefficient, is the number before the element., and indicates the ratio of reactants to products in terms of moles. Charges are shown in superscript for individual ions, but not for ionic compounds. Polyatomic ions are separated by parentheses so the ion will not be confused with the number of ions.

Provide a general overview of chemical reactions

Chemical reactions measured in human time can take place quickly or slowly. They can take fractions of a second or billions of years. the rates of chemical reactions are determined by how frequently reacting atoms and molecules interact. Rates are also influenced by the temperature and various properties, (such as shape) of the reacting materials. Catalysts accelerate chemical reactions, while inhibitors decrease reaction rates. Some types of reactions release energy in the form of heat and light. Some types of reactions involve the transfer of either electrons or hydrogen ions between reacting ions, molecules, or atoms. In other reactions, chemical bonds are broken down by heat or light to form reactive radicals with electrons that will readily form new bonds. Processes such as the formation of ozone and greenhouse gases in the atmosphere and the burning and processing of fossil fuels are controlled by radical reactions.

List some facts about DNA

Chromosomes consist of genes, which are single units of genetic information. Genes are made up of deoxyribonucleic acid (DNA). DNA is a nucleic acid located in the cell nucleus. There is also DNA in the mitochondria. DNA replicates to pass on genetic information. The DNA in almost all cells is the same. It is also involved in the biosynthesis of proteins. The model or structure of DNA is described as a double helix. A helix is a curve, and a double helix is two congruent curves connected by horizontal members. The model can be likened to a spiral staircase. It is right-handed. The British scientist Rosalind Elsie Franklin is credited with taking the x-ray diffraction image in 1952 that was used by Francis Crick and James Watson to formulate the double-helix model of DNA and speculate about its important role in carrying and transferring genetic information.

Discuss the carbon cycle of the ocean

The carbon and nutrient cycles of the ocean are processes that are due in part to the deep currents, mixing, and upwelling that occur in the ocean. Carbon dioxide (CO2) from the atmosphere is dissolved into the ocean at higher latitudes and distributed to the denser deep water. Where upwelling occurs, CO2 is brought back to the surface and emitted into the tropical air. Phytoplankton are typically single-celled organisms that are nourished by the Sun. They are photosynthetic autotrophs, meaning they convert water, carbon dioxide, and solar energy into good. They drift with the currents, produce oxygen as a byproduct, and serve as a food source. Zooplankton feed on phytoplankton. Zooplankton are heterotrophic organisms, meaning they do not synthesize their own food. Zooplankton can be single-celled creatures or much larger organisms, such as jellyfish, mollusks, and crustaceans.

Briefly define circuit, circuit breaker, resistance, resistor, transistor, semiconductor, and solid state device.

Cicuit: this refers to the movement of electric charge along a path between areas of high electric potential and areas of low electric potential. Circuit breaker: a circuit breaker stops the flow of an electric charge through a circuit by creating a break in the path. A fuse also creates abreak. Resistance: refers to the hindreance to the flow of an electric charge. Resistance is measured in Ohms. Ohms law is I=V/R, where "I" is current measured in amps, "V" is potential difference in volts, and "R" is resistnace. Resistor: this refers to a device used in a circuit that opposes the flow of an electric charge. Trnasistor: this is a divice made of a semiconductive material that can amplify or switch an electric charge. Semiconductor: this is a material with conductivity between an insulator and a conductor. These materials replaced earlier electric devices such as vacuum tubes. Solid state device: used in modern circuits, solid state devices are solid materials in which the charge carriers, or electrons, are contained entirely within the material. Examples include transistors, microprocessors, integrated circuits, light emitting diodes (LEDs), and liquid-crystal displays (LCD).

List some facts about the circulatory and skin systems, including hormonal control mechanisms, parts of hte systems, their locations, and their functions.

Circulatory: this includes the heart, blood, and blood vessels, such as veins, arteries, and capillaries. Blood transports oxygen and nutrients to cells and carbon dioxide to the lungs. Skin (integumentary): this includes skin, hair, nails, sense receptors, sweat glands, and oil glands. The skin is a sense organ, provides an exterior barrier against disease, regulates body temperature through perspiration, manufactures chemicals and hormones, and provides a place for nerves from the nervous system and parts of the circulation system to travel through. Skin has three layers: epidermis, dermis, and subcutaneous. The epidermis is the thin, outermost, waterproof layer. Basal cells are located in the epidermis. The dermis contains the sweat glands, oil glands, and hair follicles. The subcutaneous layer has connective tissue, and also contains adipose (fat) tissue, nerves, arteries, and veins.

Discuss the formation of clouds

Clouds form when air cools and warm air is forced to give up some of its water vapor becausei it can no longer hold it. This vapor condenses and forms tiny droplets of water or ice crystals called clouds. Particles, or aerosols, are needed for water vapor to form water droplets. These are called condensation nuclei. Clouds are created by surface heating mountains and terrain, rising air masses, and weather fronts. Clouds precipitate, returning the water they contain to Earth. CLouds can also create atmospheric optics. They can scatter light, creating colorful phenomena such as rainbows, colorful sunsets, and the green flash phenomenon.

Describe how frontal systems are represented on weather maps

Cold fronts are represented on weather maps as a blue line. Solid blue triangles are used to indicate the direction of movement. Warm fronts are represented with a red line. Solid red semi-circles are used to indicate the direction of the front. The cold and warm front symbols are merged and alternated to point in opposite directions to indicate a stationary front. An occluded front is represented by a purple line with alternating solid purple triangles and semicircles. A surface trough is represented by an orange dashed line. A squall or shear line is represented by a red line. Two dots and a dash are alternated to form the line. a dry line is represented by an orange line with semicircles in outline form. A tropical wave is represented by a straight orange line. An "L" is used to indicate an area of low atmospheric pressure and an "H" is used to indicate an area of high atmospheric pressure.

Define combination and decomposition reactions, and provide an equation and an example for each.

Combination, or synthesis, reactions: in a combination reaction, two or more reactants combine to form a single product (A-->B+C). These reactions are also called synthesis or addition reactions. An example is burning hydrogen in air to produce water. The equation is 2H2 (g) + O2 (g) -->2H2O-->2H2 +O2

Discuss common weather phenomena and equipment meteorologists use to measure them.

Common atmospheric conditions that are frequently measured are temperature, precipitation, wind, and humidity. These weather conditions are often measured at permanently fixed weather stations so weather data can be collected and compared over time and by region. Measurements may also be taken by ships, buoys, and underwater instruments. Measurements may also be taken under special circumstances. The measurements taken include temperature, barometric pressure, humidity, wind speed, wind direction, and precipitation. Usually, the following instruments are used: A thermometer is used for measuring temperature; a barometer is used for measuring barometric/air pressure; a hygrometer is used for measuring humidity; an anemometer is used for measuring wind speed; a weather vane is used for measuring wind direction; and a rain gauge is used for measuring precipitation.

Define and describe the following cell structure: cytosol, cytoplasm, cell membrane, endoplasmic reticulum, and mitochondria.

Cytosol: this is the liquid material in the cell. It is mostly water, but also contains some floating molecules. Cytoplasm: this is a general term that refers to cytosol and the substructures (organelles) found within the plasma membrane, but not within the nucleus. Cell membrane (plasma membrane): this defines the cell by acting as a barrier. It also determines what is allowed to enter and exit the cell. Endoplasmic reticulum: the two types of endoplasmic reticulum are rough (has ribosomes on the surface) and smooth (does not have ribosomes on the surface). It is a tubular network that comprises the transport system of a cell. It is fused to the nuclear membrane and extends through the cytoplasm to the cell membrane. Mitochondrion (plural mitochondria): these cell structures vary in terms of size and quantity. Some cells may have one mitochondrion, while others have thousands. This structure performs various functions such as generating ATP, and is also involved in cell growth and death. Mitochondria contain their own DNA that is separate from that contained in the nucleus.

Compare and contrast direct and alternating current.

DC is the flow of an electric charge in one direction. Batteries and solar cells typically use dc. AC is current that periodically reverses direction. AC is typically used in houses and other buildings. A diode is an electronic device used to conduct electric current in one direction. The process of conduction in one direction is known as rectification. A rectifier is used to convert alternating current to direct current. Diodes are also used to remove modulation from radio signals. An inverter is the opposite of a rectifier in that it converts direct current to alternating current. Electromotive force (EMF) is what causes electrons to move when there is potential difference between two points (voltage). Devices that can provide emf include batteries, voltaic cells, thermoelectric devices, solar cells, electrical generators, transformers, and Van de Graaff generators.

Discuss the structure of DNA

DNA has a double helix shape and is compact. It consists of nucleotides, which consist of a 5-carbon sugar (pentose), a phos/phate group, and a nitrogenous base. Two bases pair up to form the rungs of the ladder. The "side rails" or backone consists of the covalently bonded sugar and phosphate. The bases are attached to each other with hydrogen bonds, which are easily dismantled so replication can occur. Each base is attached to a phosphate and to a sugar. There are four types of nitrogenous bases: adenine (A), guanine (G), cytosine (C), and thymine (T). THere are about 3 billion bases in human DNA. The bases are mostly the same in everybody, but their order is different. It is the order of these bases that creates diversity in people. Adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G).

Describe the process of deposition

Deposition, or sedimentation, is the geological process in which previously eroded material is transported or added to a land form or land mass. Erosion and sedimentation are complementary geological processes. Running water causes a substantial amount of deposition of transported materials in both fresh water and coastal areas. Examples include gravity transporting material down the slope of a mountain and depositing it at the base of the slope. Another example is when a sandstorm deposits particles in other locations. When glaciers melt and retreat, it can result in the deposition of sediments. Evaporation is also considered to cause deposition since dissolved materials are left behind when water evaporates. Deposition can include the build up of organic materials. For example, chalk is partially made up of small calcium carbonate skeletons of marine plankton, which helps create more calcium carbonate from chemical processes.

Explain metathesis (acid/base) reactions.

Double replacement reactions are metathesis reactions. In a double replacement reaction, the chemical reactants exchange ions but the oxidation state stays the same. One of the indicators of this sis the formation of a solid precipitate. In acid/base reactions, an acid is a compound that can donate a proton, while a base is a compound that can accept a proton. In these types of reactions, the acid and base react to form a salt and water. When the proton is donated, the base becomes water and the remaining ions forma salt. One method of determining whether a reaction is an oxidation/reduction or a metathesis reaction is that the oxidation number of atoms does not change during a metathesis reaction.

Explain the formation of the Earth.

Earth's early development began after a supernova exploded. This led to the formation of the Sun out of hydrogen gas and interstellar dust. Theses same elements swirled around the newly formed sun and formed the planets, including earth. Scientist theorize that that about 4.5 billion years ago Earth was a chunk of rock surrounded by a cloud of gas. It is believed it lacked water and the type of atmosphere that exists today. Heat from radioactive materials in the rock and pressure in the earth's interior melted the interior. The caused the heavier materials, such as iron, to sink. Lighter silicate-type rocks rose to the Earth's surface. These rocks formed the Earth's earliest crust. Other chemicals also rose to the Earth's surface, helping to form the water and atmosphere. There is one material that has been dated by scientists and found to be 4.4 billion years old. The material is zircon, which consists of zirconium, silicon, and oxygen. Zircon is a mineral that has a high resistance to weathering.

Discuss ecosystem stability and ecologic succession

Ecosystem stability: this is a concept that states that a stable ecosystem is perfectly efficient. Seasonal changes or expected climate fluctuations are balanced by homeostasis. It also states that interspecies interactions are part of the balance of the system. Four principles of ecosystem stability are that waste disposal and nutrient replenishment by recycling is complete, the system uses sunlight as an energy source, biodiversity remains, and populations are stable in that they do not over consume resources. Ecologic succession: this is the concept that states that there is an orderly progression of change within a community. An example of primary succession is that over hundreds of years bare rock decomposes to sand, which eventually leads to soil formation, which eventually leads to the growth of grasses and trees. Secondary succession occurs after a disturbance or major event that greatly affects a community, such as a wild fire or construction of a dam.

Discuss Ohm's law

Electric current experience resistance as they travel through a circuit. Different objects have different levels of resistance. The ohm is the measurement unit of electric resistance. The symbol is the Greek letter omega. Ohm's Law, which is expressed as I=V/R, states that current flow (I, measured in amps) through an object is equal to the potential difference from one side to the other (V, measured in volts) divided by resistance (R measured in ohms) An object with a higher resistance will have a lower current flow through it given the same potential difference.

Explain the basics of electric current movement through circuits as it relates to potential.

Electric current is the sustained flow of electrons that are part of an electric charge moving along a path in a circuit. This differs from a static electric charge, which is a constant non-moving charge rather than a continuous flow. The rate of flow of electric charge is expressed using the ampere (amp or A) and can be measured using an ammeter. A current of 1 ampere means that 1 coulomb of charge passes through a given area every second. Electric charges typically only move from areas of high electric potential to areas of low electric potential. To get charges to flow into a high potential area, you must connect it to an area of higher potential, by introducing a battery or other voltage source.

Discuss electric potential

Electric potential, or electrostatic potential or voltage, is an expression of potential energy per unit of charge. It is measured in volts (V) as a scalar quantity. THe formula used is V=E/Q, where V is voltage, E is electrical potential energy, and Q is the charge. Voltage is typically discussed in context of electric potential difference between two points in a circuit. Voltage can also be thought of as a measure of the rate at which energy is drawn from a source in order to produce a flow of electric charge.

Explain electron configuration and notation.

Electron configuration is a trend whereby electrons fill shells and subshells in an element in a particular order and with a particular number of electrons. The chemical properties of the elements reflect their electron configurations. Energy levels (shells) do not have to be completely filled before the next one begins to be filled. A common shorthand method for electron configuration notation is to use a noble gas in a bracket to abbreviate the shells that elements have in common.

Explain how to read a molecular formula and list some familiar molecular compounds

Elements are represented in upper case letter. If there is no subscript, it indicates there is only one atom of the element. Otherwise, the subscript indicates the number of atoms. In molecular formulas, elements are organized according to the Hill system. Carbon is first, hydrogen comes next, and the remaining elements are listed in alphabetical order. If there is no carbon, all elements are listed alphabetically. There are a couple of exceptions to these rules. First, oxygen is usually listed last in oxides. Second, in ionic compounds the positive ion is listed first, followed by the negative ion. In CO2 for example, C indicates 1 atom of carbon and O2 indicates 2 atoms of oxygen. The compound is carbon dioxide. THe formula for ammonia (an inorganic compound) is NH3, which is one atom of nitrogen and three of hydrogen.

Compare and contrast endothermic and exothermic reactions.

Endothermic reactions are chemical reactions that absorb heat and exothermic reactions are chemical reactions that release heat. Reactants are the substances that are consumed during a reaction, while products are the substances that are produced or formed. A balanced equation is one that uses reactants, products, and coefficients in such a way that the number of each type of atom (law of conservation of mass) and the total charge remains the same. The reactants are on the left side of hte arrow and the products are on the right. The heat difference between endothermic and exothermic reactions is caused by bonds forming and breaking. If more energy is needed to break the reactant bonds than is released when they form, the reaction is endothermic. Heat is absorbed and the environmental temperature decreases. If more energy is released when product bonds form than is needed to break the reactant bonds, the reaction is exothermic. Heat is released and the environmental temperature increases.

Discuss Newton's third law of motion

For every force, there is an equal and opposite force.

Discuss the difference between polar and nonpolar solutes and solvents.

For solvation to occur, bonds similar in strength must be broken and formed. Nonpolar substances are usually soluble in nonpolar solvents. ionic and polar matter is usually soluble in polar solvents. Water is a polar solvent. Oil is nonpolar. Therefore, the saying "oil and water don't mix" is quite true. Heptane is another nonpolar liquid that is said to be immiscible in water, meaning it can't combine with water. The hydrogen bonds of the water molecules are stronger than the London dispersion forces of the heptane. Polar molecules such as NH3, SO2, and H2S are termed hydrophilic, meaning they readily combine with water. Nonpolar molecules, including the noble gases and other gases such as He, Ne, and CO2 are termed hydrophobic, meaning they repel, or do not readily combine with water. One way to remember this is that "like dissolves like" Polar solvents dissolve polar solutes, while nonpolar solvents dissolve nonpolar solutes.

Define latitude, longitude, and equator

For the purposes of tracking time and location, the Earth is divided into sections with imaginary lines. lines that run vertically around the globe through the poles are lines of longitude, sometimes called meridians. The Prime Meridian is the longitudinal reference point of 0. Longitude is measured in 15-degree increments toward the east or west. Degrees are further divided into 60 minutes, and each minute is divided into 60 seconds. Lines of latitude run horizontally around the Earth parallel to the equator, which is the 0 reference point and the widest point of the Earth. Latitude is the distance north or south from the equator, and is also measured in degrees, minutes, and seconds.

Explain what fossils are and how they are formed.

Fossils are preservations of plants, animals, their remains, or their traces that date back to about 10,000 years ago. Fossils and where they are found in rock strata makes up the fossil record. Fossils are formed under a very specific set of conditions. The fossil must not be damaged by predators and scavengers after death, and the fossil must not decompose. Usually, this happens when the organism is quickly covered with sediment. This sediment builds up and molecules in the organism's body are replaced by minerals. Fossils come in an array of sizes, from single-celled organisms to large dinosaurs.

Discuss the type of information provided by fossils.

Fossils provide a wealth of information about the past, particularly about the flora and fauna that once occupied the Earth, but also about the geologic history of the Earth itself and how Earth and its inhabitants came to be. Some fossilized remains in the geohistorical record exemplify ongoing processes in the Earth's environment, such as weathering, glaciation, and volcanism. These have all led to evolutionary changes in plants and animals. Other fossils support the theory that catastrophic events caused drastic changes in the Earth and its living creatures. One example of this type of theory is that a meteor struck the Earth and caused dinosaurs to become extinct. Both types of fossils provide scientists with a way to hypothesize whether these types of events will happen again.

Define frequency, period, and speed as they relate to waves.

Frequency is a measure of how often particles in a medium vibrate when a wave passes through the medium with respect to a certain point or node. Usually measured in Hertz, frequency might refer to cycles per second, vibrations per second, or waves per second. One HZ is equal to one cycle per second. Period is a measure of how long it takes to complete a cycle. It is the inverse of frequency; where frequency is measured in cycles per second, period can be thought of as seconds per cycle, though it is measured in units of time only. Speed refers to how fast or slow a wave travels. It is measured in terms of distance divided by time. While frequency is measured in terms of cycles per second, speed might be measured in terms of meters per second.

Discuss friction

Friction is a force that arises as a resistance to motion where two surfaces are in contact. Two types of friction are static and kinetic. To illustrate these concepts, imagine a book resting on a table. The force of the weight (W) is equal and opposite to the force of the table on the book, or the normal force (N). If we exert a small force (F) on the book, attempting to push it to one side, a frictional force would arise, equal and opposite to our force. At this point, it is a static frictional force because the book is not moving. If we increase our force on the book, we will eventually cause it to move. At this point, the frictional force opposing us will be a kinetic frictional force. Generally, the kinetic frictional force is lower than static frictional force, which means that the amount of force needed to maintain the movement of the book will be less than what was needed to start it moving.

Define and discuss galaxies

Galaxies consist of stars, stellar remnants, and dark matter. Dwarf galaxies contain as few as 10 million stars, while giant galaxies contain as many as 1 trillion stars. Galaxies are gravitationally bound, meaning the stars, star systems, other gases, and dust orbits the galaxy's center. The Earth exists in the Milky Way galaxy and the nearest galaxy to ours is the Andromeda galaxy. Galaxies can be classified by their visual shape into elliptical, spiral, irregular, and starburst galaxies. It is estimated that there are more than 100 billion galaxies in the universe ranging from 1,000 to 100,000 parsecs in diameter. Galaxies are organized into clusters which form superclusters. Dark matter may account for up to 90% of the mass of galaxies. Dark matter is still not well understood.

Discuss the geologic time scale

Geologists use the geologic time scale when discussing Earth's chronology and the formation of rocks and minerals. Age is calculated in millions of years before the present time. Units of time are often delineated by geologic or paleontologic events. Smaller units of time such as eras are distinguished by the abundance and/or extinction of certain plant and animal life. For example, the extinction of the dinosaurs marks the end of the Mesozoic era and the beginning of the Cenozoic, the present, era. We are in the Holocene epoch. The supereonen compasses the greatest amount of time. It is composed of eons. Eons are divided into eras, eras into periods, and period into epochs. Layers of rock also correspond to periods of time in geochronology. Current theory holds that the Earth was formed 4.5 billion years ago.

Discuss geometric optics

Geometric optics uses the concept of rays to determine how light will propagate.Ray diagrams can illustrate the path of light through a lens. Different types of lenses refract light, either convergently or divergently, to form images. After passing through a lens, rays converge at a focal point. Collimated rays are nearly parallel, and can be thought of as having no focal point. There are many types and combinations of lenses. Convergent lenses, also called positive lenses, are thicker in the middle and thinner at the edges. Rays are focused to a point. Divergent lenses, also called negative lenses, are thicker at the ends and thinner in the middle. Rays spread apart, or diverged. A convex lens is bowed outward, either at one vertical surface or both. A convex lens with two convex surfaces may also be termed biconvex or double convex. A concave lens is bowed inward, while a planar lens is flat.

List some facts about gravitational force

Gravitational force is a universal force that causes every object to exert a force on every other object. The gravitational force between two objects can be described by the formula, F=Gm1m2/r2, where m1 and m2 are the masses of two objects, r is the distance between them, and G is the gravitational constant, G =6.672 x 10^-11 N-m2/kg2. In order for this force to have a noticeable effect, one or both of the objects must be extremely large, so the equation is generally only used in problems involving planetary bodies. For problems involving objects on the earth being affected by the earth's gravitational pull, the force of gravity is simply calculated as F=mg, where g is 9.81 m/s2 toward the ground.

Describe the Paleozoic era in the context of the geologic time scale and explain why it was important.

The Paleozoic era began about 542 million years ago and lasted until 251 million years ago. It is further divided into six periods. The Paleozoic era began after the supercontinent Pannotia started to break up and at the end of a global ice age. By the end of the era, the supercontinent Pangaea had formed. The beginning of the Paleozoic era is marked by Cambrian Explosion, a time where there were abundant life forms according to the fossil record. The end of the era is marked by one of the major extinction events, the Permian extinction, during which almost 90% of the species living at the time became extinct. Many plant and animal forms appeared on the land and in the sea during this era. It is also when large land plants first appeared in fossil record. There are many invertebrates found in the fossil record of the Paleozoic era, and fish, amphibians, and reptiles also first appeared in the fossil record during this era. There were also large swamps and forests, some of which were formed into coal deposits that exist today.

Define gyres and the Coriolis effect. Discuss the movement of surface currents and name the major types.

Gyres are surface ocean currents that form large circular patterns. In the Northern Hemisphere, they flow clockwise. In the Southern Hemisphere, they flow counterclockwise. These directions are caused by the Coriolis effect. The Coriolis effect occurs due to the fact that the Earth is a rotating object. In the northern Hemisphere, currents appear to be curving to the right. In the Southern Hemisphere, currents appear to be curving to the left. This is because the Earth is rotating. Gyres tend to flow in the opposite direction near the Earth's poles. In the proton of the Pacific Ocean north of the equator, the major currents are North Pacific, California, North Equatorial, and Kuroshio. In the South Pacific, they are South Equatorial, East Australia, South Pacific, and Peru. In the North Atlantic, they are the North Atlantic Drift, Canary, North Equatorial, and Gulf Stream. In the South Atlantic, they are South Equatorial, Brazil, South Atlantic, and Benguela.

Discuss relative humidity, absolute humidity, and dew point temperature.

Humidity refers to water vapor contained i the air. The amount of moisture contained in air depends upon its temperature. The higher the air temperature, the more moisture it can hold. These higher levels of moisture are associated with higher humidity. Absolute humidity refers to the total amount of moisture air is capable of holding at a certain temperature. Relative humidity is the ratio of water vapor in the air compared to the amount the air is capable of holding at its current temperature. A temperature decreases, absolute humidity stays the same and relative humidity increases. A hygrometer is a device used to measure humidity. The dew point is the temperature at which water vapor condenses into water at a particular humidity .

Define the following postzygotic barriers to reproduction: hybrid viability, hybrid sterility, hybrid breakdown, hybrid zygote abnormality, allopatric speciation, sympatric speciation, and parapatric speciation.

Hybrid viability: this is when a hybrid zygote does not reach maturity. Hybrid sterility: this is also known as hybrid infertility. It occurs when two species produce a hybrid offspring that reaches maturity, but is sterile. An example of this is the mule.

Discuss hydrogen bonds, particularly hydrogen bonds in water

Hydrogen bonds are weaker than covalent and ionic bonds, and refer to the type of attraction in an electronegative atom such as oxygen, fluorine, or nitrogen. Hydrogen bonds can form within a single molecule or between molecules. A water molecule is polar, meaning it is partially positively charged on one end (the hydrogen end) and partially negatively charged on the other (oxygen end). This is because the hydrogen atoms are arranged around the oxygen atom in a close tetrahedron. Hydrogen is oxidized (its number of electrons is reduced) when it bonds with oxygen to form water. Hydrogen bonds tend not only to be weak, but also short-lived. They also tend to be numerous. Hydrogen bonds give water many of its important properties, including its high specific heat and high heat of vaporization, its solvent qualities, its adhesiveness and cohesiveness, it hydrophobic qualities, and its ability to float in its solid form. Hydrogen bonds are also an important component of proteins, nucleic acids, and DNA.

Explain what igneous rock is and how it is formed.

Igneous rock is formed from magma, which is molten material originating from beneath the Earth's surface. Depending upon where magma cools, the resulting igneous rock can be classified as intrusive, plutonic, hypabyssal, extrusive, or volcanic. Magma that solidifies at a depth is intrusive, cools slowly, and has a coarse grain as a result. An example is granite. Magma that solidifies at or near the surface is extrusive, cools quickly, and usually has a fine grain. An example is basalt. Magma that actually flows out of the Earth's surface is called lava. Some extrusive rock cools so quickly that crystals do not have time to form. These rocks have a glassy appearance. An example is obsidian. Hypabyssal rock is igneous rock that is formed at medium depths.

Discuss the periodic table groups

In the periodic table, the groups are the columns numbered 1 through 18 that group elements with similar outer electron shell configurations. Since the configuration of the outer electron shell is one of the primary factors affecting an element's chemical properties, elements within the same group have similar chemical properties. Perious naming conventions for groups have included the use of Raman numerals and upper-case letters. Currently, the periodic table groups are Group 1, alkali metals; Group 2, alkaline earth metals; Groups 3-12, transition metals; Group 13, boron family; Group 14; carbon family; Group 15, pnictogens; group 16 chalcogens; Group 17, halogens; Group 18, noble gases.

Describe how periodic table periods and blocks relate to electrons.

In the periodic table, there are seven periods (rows), and within each period there are blocks that group elements with the same outer electron subshell. The number of electrons in that outer shell determines which group an element belongs to within a given block. Each row's number, (1,2,3, etc.) corresponds to the highest number electron shell that is in use. For example, row 2 uses only electron shells 1 and 2, while row 7 uses shells from 1-7.

Define ionization energy, electron affinity, and polar bond

Ionization energy: is the energy required for an electron to free itself from the grip of its neutral atom. Ionization energy increases across a row. Groups on the left of the table have fewer valence electrons and noble gases have the maximum number of valence electrons (a filled outer shell). Ionization energy can be measured in kilojoules (kj) per mole or electron volts (ev) per atom (1kj/mol=0.010364 eV/atom). Elements with low ionization energies are highly reactive because they can easily give up electrons. Electron affinity: is a way to measure the change in energy when a negative ion is formed by adding an electron to a neutral atom. Polar bond: this refers to a covalent type of bond with a separation of charge. One end is negative and the other is positive. They hydrogen-oxygen bond in water is one example of polar bond.

Define isomerization and neutralization reactions, and provide an equation and an example for each.

Isomerization, or rearrangement, is the process of forming a compound's isomer. Within a compound, bonds are reformed. The reactant and product have the same molecular formula, but different structural formulas and different properties (A-->B or A-->A') For example, butane (C4H10) is a hydrocarbon consisting of four carbon atoms in a straight chain. Heating it to 100 degrees Celsius or higher in the presence of a catalyst forms isobutane (methylpropane), which has branched-chain structure. Boiling and freezing points are greatly different for butane and isobutane. A rearrangement reaction occurs within the molecule. A neutralization, acid-base, or proton transfer reaction is when one compound acquires H+ from another. These types of reactions are also usually double displacement reactions. The acid has an H+ that is transferred to the base and neutralized to form salt.

List and describe the phases of the moon

It takes about one month for the moon to go through all the phases. Waxing refers to the two weeks during which the moon goes from a new moon to a full moon. About two weeks is spent waning, going from a full moon to a new moon. The lit part of the moon always faces the Sun. The phases of waxing are; new moon, during which the moon is not illuminated and rises and sets with the Sun; crescent moon, during which a tiny sliver is lit; first quarter, during which half the moon is lit and the phase of the moon is due south on the meridian; gibbous, during which more than half of the moon is lit and has a shape similar to a football; right side, during which the moon is lit; and full moon, during which the moon is fully illuminated, rises at sunset, and sets at sunrise. After a full moon the moon is waning. The phases of waning are; gibbous, during which the left side is lit and the moon rises after sunset and sets after sunrise; third quarter, during which the moon is half lit and rises at midnight and sets at noon; crescent, during which a tiny sliver is lit; and new moon, during which the moon is not illuminated and rises and sets with the sun.

List the four outer, gas giant planets and some characteristics of each

Jupiter is the fifth planet from the Sun and the largest planet in the solar system. It consists mainly of hydrogen, and 25% of its mass is made up of helium. It has a fast rotation and has clouds in the tropopause composed of ammonia crystals that are arranged into bands sub-divided into lighter-hued zones and darker belts causing storms and turbulence. Jupiter has wind speeds of 100 m/s, a planetary ring, 63 moons, and a Great Red Spot, which is an anticyclonic storm. Saturn is the sixth planet from the Sun and the second largest planet in the solar system. It is composed of hydrogen, some helium, and trace elements. Saturn has a small core of rock and ice, a thick layer of metallic hydrogen, a gaseous outer layer, wind speeds of up to 1,800 km/h, a system of rings, and 61 moons. Uranus is the seventh planet from the Sun. Its atmosphere is composed mainly of hydrogen and helium, and also contains water, ammonia, methane, and traces of hydrocarbons. With a minimum temperature of 49 K, Uranus has the coldest atmosphere. Uranus has a ring system, a magnetosphere, and 13 moons. Neptune is the eighth planet from the Sun and is the planet with the third largest mass. It has 12 moons, and atmosphere similar to Uranus, a Great Dark Sport, and the strongest sustained winds of any planet (wind speeds can be as high as 2,100 km/h). Neptune is cold (about 55 K) and has a fragmented ring system.

Discuss latitudinal variation of solar radiation and list the corresponding ecosystems.

Latitude is a measurement of the distance from the equator. The distance from the equator indicates how much solar radiation a particular area receives. The equator receives more sunlight, while polar areas receive less. The Earth tilts slightly on its rotational axis. This tilt determines the seasons and affects weather. There are eight biomes or ecosystems with particular climates that are associated with latitude. Those in the high latitudes, which get the least sunlight, are tundra and taiga. Those in the mid latitudes are grassland, temperate forests, and chaparral. THos in latitudes closest to the equator are the warmest. The biomes are desert and tropical rain forest. The eighth biome is the ocean, which is unique because it consists of water and spans the entire globe. Insolation refers to incoming solar radiation. Diurnal variations refer to the daily changes in insolation. The greatest insolation occurs at noon.

Define Lewis formulas and Kekule' diagrams

Lewis formulas show the bonding or nonbonding tendency of specific pairs of valence electrons. Lewis dot diagrams use dots to represent valence electrons. Dots are paired around an atom. When an atom forms a covalent bond with another atom, the elements share the dots as they would electrons. Double and triple bonds are indicated with additional adjacent dots. Methane (CH4), for instance, would be shown as a C with 2 dots above, below, and to the right and left and an H next to each set of dots. In structural formulas, the dots are single lines. Kekule' diagrams, like Lewis dot diagrams, these are two-dimensional representations of chemical compounds. Covalent bonds are shown as lines between elements. Double and triple bonds are shown as two or three lines and unbonded valence electrons are shown as dots.

Discuss visible light as part of the electromagnetic spectrum

Light is the portion of the electromagnetic spectrum that is visible because of it s ability to stimulate the retina. It is absorbed and emitted by electrons, atoms, and molecules that move from one energy level to another. Visible light interacts with matter through molecular electron excitation (which occurs in the human retina) and through plasma oscillations (which occur in metals). Visible light is between ultraviolet and infrared light one the spectrum. THe wavelengths of visible light cover a range from 380 nm (violet) to 760 (red). Different wavelengths correspond to different colors.

List the four inner terrestrial planets and some characteristics of each

Mercury is the closest to the Sun and is also the smallest planet. It orbits the Sun every 88 days, has no satellites or atmosphere, has a moon-like surface with craters, appears bright, and is dense and rocky with a large iron core. Venus is the second planet from the Sun. It orbits the Sun every 225 days, is very bright, and is similar to Earth in size, gravity, and bulk composition. It has a dense atmosphere composed of carbon dioxide and some sulfur. It is covered with reflective clouds made of sulfuric acid and exhibits signs of volcanism. Lightning and thunder have been recorded on Venus's surface. Earth is the third planet from the Sun. It orbits the Sun every 365 days. Approximately 71% of its surface is salt-water oceans. The Earth is rocky, has an atmosphere composed mainly of oxygen and nitrogen, has one moon, and supports millions of species. It contains the only known life in the solar system. Mars is the fourth planet from the Sun It appears reddish due to iron oxide on the surface, has a thin atmosphere, has a rotational period similar to Earth's, and has seasonal cycles. Surface features of Mars include Volcanoes, valleys, deserts, and polar ice caps. Mars has impact craters and the tallest mountains, largest canyon, and perhaps the largest impact crater yet discovered.

Compare and contrast weather, climate, and meteorology.

Meteorology is the study of the atmosphere, particularly as it pertains to forecasting the weather and understanding its processes. Weather is the condition of the atmosphere at any given moment. Most weather occurs in the troposphere. Weather includes changing events such as clouds, storms, and temperature, as well as more extreme events such as tornadoes, hurricanes, and blizzards. Climate refers to the average weather for a particular area over time, typically at least 30 years. Latitude is an indicator of climate. Changes in climate occur over long time periods.

Discuss models for the flow of electric charge.

Models that can be used to explain the flow of electric current, potential and circuits include water, gravity and roller coasters. For example, just as gravity is a force and a mass can have a potential for energy based on its location, so can a charge within an electrical field. Just as a force is required to move an object uphill, a force is also required to move a charge from a low to high potential. Another example is water. Water does not flow when it is level. If it is lifted to a point and then placed on a downward path, it will flow. A roller coaster car requires work to be performed to transport it to a point where it has potential energy (the top of a hill). Once there, gravity provides the force for it to flow (move) downward. If either path is broken, the flow or movement stops or is not completed.

Define molar mass, Charles's law and Boyle's law.

Molar mass refers to the mass of one mole of a substance (element or compound), usually measured in grams per mole (g/mol). This differs from molecular mass in that molecular mass is the mass of one molecule of a substance relative to the atomic mass unit (amu). Charles's law: This states that gases expand when they are heated. It is also known as the law of volumes. Boyle's law: this state that gases contract when pressure is applied to them. It also states that if temperature remains constant, the relationship between absolute pressure and volume is inversely proportional. When one increases, the other decreases. Considered a specialized case of the ideal gas law, Boyle's law is sometimes known as the Boyle-Mariotte law.

Discuss high, middle, and low cloud types

Most clouds can be classified according to the altitude of their base above Earth's surface. High clouds occur at altitudes between 5,000 and 13,000 meters. Middle clouds occur at altitudes between 2,000 and 7,000 meters. Low clouds occur from the Earth's surface to altitudes of 2,000 meters. Types of high clouds include cirrus (Ci), thin whisp mare's tails that consists office; cirrocumulus (Cc), small, pillow-like puffs that often appear in rows; and cirrostratus (Cs), think, sheetlike clouds that often cover the entire sky. Types of middle clouds include altocumulus (Ac), gray-white clouds that consist of liquid water; and altostratus (As), grayish or blue-gray clouds that span the sky. Types of low clouds include stratus (st), gray and fog like clouds consisting of water droplets that take up the whole sky; stratocumulus (Sc), low-lying, lumpy gray clouds; and nimbostratus (Ns), dark gray clouds with uneven bases that indicate rain or snow. Two types of clouds, cumulus (Cu) and cumulonimbus (Cb), are capable of great vertical growth. They can start at a wide range of altitudes, from Earth's surface to altitudes of 13,000 meters.

Explain the processes involved in the formation, movement, and breaking of ocean waves.

Most waves in the ocean are formed by winds. The stronger the winds are, the larger the waves will be. The highest point of a wave is the crest. The lowest point of the wave is a trough. The wavelength is measured from crest to crest. The wave height is measured from the trailing trough to the peak of the crest. The wave frequency refers to the number of wave crests passing a designated point each second. A wave period is the time it takes for a wave crest to reach the point of the wave crest of the previous wave. The energy in the wave runs into the shallow sea floor. This causes the wave to become steeper and then fall over, or break.

Discuss troposheric circulation

Most weather takes place in the troposphere. Air circulates in the atmosphere by convection and in various types of "cells". Air near the equator is warmed by the Sun and rises. Cool air rushes under it, and the higher, warmer air flows toward Earth's poles. At the poles, it cools and descends to the surface. It is now under the hot air, and flows back to the equator. Air currents coupled with ocean currents move heat around the planet, creating winds, weather, and climate. Winds can change direction with the seasons. For example, in Southeast Asia and India, summer monsoons are caused by air being heated by the Sun. This air rises, draws moisture from the ocean, and causes daily rains. In winter, the air cools, sinks, pushes the moist air away, and creates dry weather.

Define motion and displacement

Motion is a change in the location of an object, and is the result of an unbalanced net force action on the object. Understanding motion requires the understanding of three basic quantities: displacement, velocity, and acceleration. When something moves from one place to another, it has undergone displacement. Displacement along a straight line is very simple example of a vector quantity. If an object travels from position x = -5 cm to x = 5 cm, it has undergone a displacement of 10 cm. If it transverses the same path in the opposite direction, its displacement is -10cm. A vector that spans the object's displacement in the direction of travel is known as a displacement vector.

Provide an example of a simple circuit.

Movement of electric charge along a path between areas of high electric potential and low electric potential, with a resistor or load device between them, is the definition of a simple circuit. It is a closed conducting path between the high and low potential points, such as the positive and negative terminals on a battery. One example of a circuit is the flow from one terminal of a car battery to another. The electrolyte solution of water and sulfuric acid provides work in chemical form to start the flow A frequently used classroom example of circuits involves using a D cell battery, a small light bulb, and a piece of copper wire to create a circuit to light the bulb.

Discuss Newton's first two laws of motion

Newton's First Law: An object at rest or in motion will remain at rest or in motion unless acted upon by an external force. This phenomenon is commonly referred to as inertia, the tendency of a body to remain in its present state of motion. In order for the body's state of motion to change, it must be acted on by an unbalanced force. Newton's Second Law: An object's acceleration is directly proportional to the net force action on the object, and inversely proportional to the net force acting on the object, and inversely proportional to the object's mass. It is generally written in equation form F=ma, where F is net force action on a body, m is the mass of the body, and a is its acceleration. Note that since the mass is always a positive quantity, the acceleration is always in the same direction as the force.

Define and discuss nomenclature for organic compounds

Nomenclature refers to the manner in which a compound is named. First, it must be determined wheter the compound is ionic (formed through electron transfer between cations and anions) or molecular (formed through electron sharing between molecules). When dealing with an ionic compound, the name is determined using the standard naming conventions for ionic compounds. This involves indicating the positive element first (the charge must be defined when there is more than one option for the valency) followed by the negative element plus the appropriate suffix. The rules for naming a molecular compound are as follows: write elements in order of increasing group number and determine the prefix by determining the number of atoms. Exclude mono for the first atom. The name for C02, for example, is carbon dioxide. The end of oxygen is dropped and "ide" is added to make oxide, and the prefix "di" is used to indicate there are two atoms of oxygen.

Explain oxidation/reduction reactions

One way to organize chemical reactions is to sort them into two categories: oxidation/reduction reactions (also called redox reactions)anc metathesis reactions (which include acid/base reactions). Oxidation/reduction reactions can involve the transfer of one or more electrons, or they can occur as a result of the transfer of oxygen, hydrogen, or halogen atoms. The species that loses electrons is oxidized and is referred to as the reducing agent. The species that gains electrons is reduced and is referred to as the oxidizing agent. The element undergoing oxidation experiences an increase in its oxidation number, while the element undergoing reduction experiences a decrease in its oxidation number. Single replacement reactions are types of oxidation/reduction reactions. In a single replacement reaction, electrons are transferred from one chemical species to another. The transfer of electrons results in changes in the nature and charge of the species.

Discuss the formation of mountains by folding and faulting

Orogeny refers to the formation of mountains, particularly the processes of folding and faulting caused by plate tectonics. Folding is when layers of sedimentary rock are pressed together by continental plate movements. Sections of rock that are folded upward are called anticlines. Sections of rock that are folded downward are called synclines. Examples of folded mountains are the Alps. and the Himalayans. Fault-block mountains are created when tectonic plate movement produces tension that results in displacement. Mountains in the Southwest United States are examples of fault-blocking mountains. Mountains can also be caused by volcanic activity and erosion.

Discuss DNA replication

Pairs of chromosomes are composed of DNA, which is tightly wound to conserve space. When replication starts, it unwinds The steps in DNA replication are controlled by enzymes. The enzyme helicase instigates the deforming of hydrogen bonds between the bases to split the two strands. The splitting begins at the A-T bases (adenine and thymine) as there are only two hydrogen bonds. The cytosine-guanine base pair has three bonds. THe term "origin of replication" is used to refer to where the splitting starts. The portion of the DNA that is unwound to be replicated is called the replication fork. Each strand of DNA is transcribed by an mRNA. It copies the DNA onto itself, base by base, in a complementary manner. The exception is that uracil replaces thymine.

Define pitch, loudness, sound intensity, timbre, and oscillation.

Pitch: is the quality of sound determined by frequency. For example, a musical note can be tuned to a specific frequency. A, for instance, has a frequency of 440 Hz, which is a higher frequency than middle C. Humans can detect frequencies between about 20 Hz to 20,000 Hz. Loudness: is the human's perception of sound intensity. Sound intensity: is measured as the sound power per unit area, and can be expressed in decibels. Timbre: this is a human's perception of the type or quality of sound. Oscillation: this is a measurement, usually of time, against a basic value, equilibrium, or rest point.

Explain the effect of temperature on reaction rate.

The collision theory states that for a chemical reaction to occur, atoms or molecules have to collide with each other with a certain amount of energy. A certain amount of energy is required to breach the activation barrier. Heating a mixture will raise the energy levels of the molecules and the rate of reaction (the time it takes for a reaction to complete). Generally, the rate of reaction is doubled for every 10 degrees Celsius temperature increase. However, the increase needed to double a reaction rate increases as the temperature climbs. THis is due to the increase in collision frequency that occurs as the temperature increases. Other factors that can affect the rate of reaction are surface area, concentration, pressure, and the presence of catalyst.

Briefly define power, watt, and transformer.

Power: measured in watts, electric power refers to the rate at which electrical energy is transferred by an electric circuit. It can be calculated using Joule's law: P=V*I, where"P" is power, "v" is potential difference (in volts) and "I" is current (in amps). Power can be generated, transmitted, and converted into various forms of light. Watt: a watt is the unit used to measure power. One watt is equal to one joule of energy per second. Transformer: is a device that uses induction to transfer current from one circuit to another. Two wound coils act as a pair of inductors. Voltage can be modified to be transferred to another circuit (as in transmission lines) or to a load, such as an electrical device plugged into a socket.

Define random mutations, nonrandom mating, and gene migration.

Random mutations: these are genetic changes caused by DNA errors of environmental factors such as chemicals and radiation. Mutations can be beneficial or harmful. Nonrandom mating: this refers to the fact that the probability of two individuals mating in a population is not the same for all pairs. Nonrandom mating can be caused by geographical isolation, small populations, and other factors. Nonrandom mating can lead to inbreeding (mating with a relative), which can lead to a decline in physical fitness as seen in a phenotype and the reduction of allele frequency and occurrence. Gene migration: also known as gene flow, gene migration is the movement of alleles to another population. This can occur through immigration, when individuals of a species move into an area, or through emigration, when individuals of a species move out of an area.

Discuss recombinant DNA and gene splicing.

Recombinant DNA (rDNA) refers to manipulating sequences of DNA. One portion of DNA is removed and replaced with another. Gene splicing is a way to recombine DNA. In gene splicing, base pairs of DNA are chemically cleaved. Restriction enzymes are used to perform the cutting part of gene splicing. Once base pairs are separated, different additional genetic information can be added by a vector. DNA ligase (an enzyme) is used to put the pieces back together. The process of DNA recombination happens naturally and incrementally as a result of evolution. Use of recombinant DNA produced through genetic engineering has been used in the laboratory in diagnostic, medical forensic and agricultural applications.

Discuss the scientific contributions of remote sensing.

Remote sensing refers to the gathering of data about an object or phenomenon without physical or intimate contact with the object being studied. The data can be viewed or recorded and stored in many forms (visually with a camera, audibly, or in the form of data). Gathering weather data from a ship, satellite, or buoy might be thought of as remote sensing. The monitoring of a fetus through the use of ultrasound technology provides a remote image. Listening to the heartbeat of a fetus is another example of remote sensing. Methods for remote sensing can be grouped as radiometric, geodetic, or acoustic. Examples of radiometric remote sensing include radar, laser altimeters, light detection and ranging (LIDAR) used to determine the concentration of chemicals in the air, and radiometers used to detect various frequencies of radiation. Geodetic remote sensing involves measuring the small fluctuations in Earth's gravitational field. Examples of acoustic remote sensing include underwater sonar and seismographs.

Describe some unpiloted space missions.

The first artificial object to reach another space object was Luna 2. It crashed on the Moon in 1959. The first automatic landing was by Luna 9. It landed on the moon in 1966. Mariner 2's flyby of Venus in 1962 was transmitting data from Venus was the first interplanetary surface landing, which took place in 1970. The first soft landing on Mars was in 1971. Unpiloted spacecraft have also made successful soft landings on the asteroids Eros and Itokawa, as well as Titan, a moon of Saturn. The first flyby of Jupiter was in 1973 by Pioneer 10. Pioneer 10 was also the first craft of its kind to leave the solar system. The first flyby of Mercury was in 1974 by Mariner. The first flyby of Saturn was in 1979 by Pioneer 11. The first flyby of Uranus was in 1986 by Voyager 2, which also flew by Neptune in 1989.

Explain how the geologic time scale was developed.

The first known observations of stratigraphy were made by Aristotle, who lived before the time of Christ. He observed seashells in ancient rock formations and on the beach, and concluded that the fossilized seashells were similar to current seashells. Avicenna, a Persian scholar from the 11th century, also made early advances in the development of stratigraphy with the concept of superposition. Nicolas Steno, a Danish scientist from the 17th century, expounded upon this with the belief that layers of rock are piled on top of each other. In the 18th century, Abraham Werner categorized rocks from four different periods: the Primary, Secondary, Tertiary, and Quaternary periods. This fell out of use when the belief emerged that rock layers containing the same fossils had been deposited at the same time, and were therefore from the same age. British geologists created the names for many of the time divisions in use today. For example, Devonian period was named after the county of Devon, and the Permian period was named after Perm, Russia.

Describe some notable satellites.

The first satellite to orbit the Earth was the Soviet Union's Sputnik 1 in 1957. Its two radio transmitters emitted beeps that were received by radios around the world. Analysis of the radio signals was used to gather information about the electron density of the ionosphere. Soviet success escalated the American space program. In 1958, the US put Explorer 1 into orbit. The Osumi was the first Japanese satellite, which was put into orbit in 1970. The Vanguard 1 is the satellite that has orbited the Earth the longest. It was put into orbit in 1958 and was still in orbit in June, 2009. The Mir Space Station orbited Earth for 11 years, and was assembled in space starting in 1986. It was almost continuously occupied until 1999. The International Space Station began being assembled in orbit in 1998. At 43,000 cubic feet, it is the largest manned object sent into space. It circles the Earth every 90 minutes.

The four basic organic macromolecules and the four basic building blocks involved in catabolic reactions.

The four basic organic macromolecules produced by anabolic reactions are carbohydrates (polysaccharides), nucleic acids, proteins, and lipids. The four basic building blocks involved in catabolic reactions are monosaccharides (glucose), amino acids, fatty acids (glycerol), and nucleotides.

Compare and contrast the function and structure of cells in living organisms.

The functions of plant and animal cells vary greatly, and the functions of different cells within a single organism can also be vastly different. Animal and plant cells are similar in structure in that they are eukaryotic, which means they contain a nucleus. The nucleus is a round structure that controls the activities of the cell and contains chromosomes. Both types of cells have cell membranes, cytoplasm, vacuoles, and other structures. The main difference between the two is that plant cells have a cell wall made of cellulose that can handle high levels of pressure within the cell, which can occur when liquid enters a plant cell. Plant cells have chloroplast that are used during the process of photosynthesis, which is the conversion of sunlight into food. Plant cells usually have one large vacuole, whereas animal cells can have many smaller ones. Plant cells have a regular shape, while the shapes of animal cells can vary.

Discuss allele frequency and what affects it.

The gene pool refers to all alleles of a gene and their combinations. The Hardy-Weinberg principle (or Castle-Hardy-Weinberg principle) postulates that the allele frequency for dominant and recessive alleles will remain the same in a population through successive generations if certain conditions exist. These conditions are: no mutations, large populations, random mating, no migration, and equal genotypes. This is an ideal and not how most populations function. Changes in the frequency and types of alleles in a gene pool can be caused by gene flow, random mutation, nonrandom mating, and genetic drift. In organisms that reproduce by sexual reproduction, reproduction isolation is defined as something that acts as a barrier to two species reproducing. These barriers are classified as prezygotic and postzygotic.

Discuss tides in more detail

The gravitational pull of the Sun and Moon causes the oceans to rise and fall each day, creating high and low tides. Most areas have two high tides and two low tides per day. Because the Moon is closer to the Earth than the Sun, its gravitational pull is much greater. The water on the side of the Earth that is closest to the Moon and the water on the opposite side experience high tide. The two low tides occur on the other sides. This changes as the Moon revolves around the Earth. Tidal range is the measurement of hte height difference between low and high tide. Tidal range also changes with the location of the Sun and Moon throughout the year, creating spring and neap tides. When all these bodies are aligned, the combined gravitational pull is greater and the tidal range is also greater. This is what creates the spring tide. The neap tide is when tidal range is at its lowest, which occurs when the Sun and Moon are not at right angles.

Give some examples of homeostasis and discuss hormone pairs.

The hormones insulin and glucagon (antagonistic pair of hormones are involved in negative feedback loops in the liver's control of blood sugar levels. Alpha cells secrete glucagon when the concentration of blood glucose decreases. Glucagon is broken down and fatty acids and amino acids are converted to glucose. once there is more glucose, glucagon secretion is reduced. Beta cells secrete insulin when the concentration of blood glucose increases. This leads to the liver absorbing glucose. Glucose is converted to glycogen, and fat tand the concentration of glucose is decreased. Insulin production is then reduced. Hormones work in other ways aside from antagonistically. For example, follicle stimulating hormone (FSH) increases the production of estrogen. Once estrogen reaches a certain level, it suppresses FSH production. In some cases, a single hormone can increase or decrease the level of a substance.

Discuss the perception of color

The human brai interprets or perceives visible light, which is emitted from the sun and othewr stars, as color. For example, when the entire wavelength reaches the retina, the brain perceives the color white. When no part of the wavelength reaches the retina, the brain perceives the color black. The particular color of an object depends upon what is absorbed and what is transmitted or reflected. For example, a leaf consists of chlorophyll molecules, the atoms of which absorb all wavelengths of the visible light spectrum except for green, which is why a leaf appears green. Certain wavelengths of visible light can be absorbed when they interact with matter. Wavelengths that are not absorbed can be transmitted by transparent materials or reflected by opaque materials.

Explain the processes involved in the hydrologic cycle

The hydrologic, or water, cycle refers to water movement on, above, and in the Earth. Water can be in any one of its three states during different phases of the cycle. The three states of water are liquid water, frozen ice, and water vapor. Processes involved in the hydrologic cycle include precipitation, canopy interception, snow melt, runoff, infiltration, subsurface flow evaporation, sublimation, advection, condensation, and transpiration.Precipitation occurs when condensed water vapor falls to Earth. Examples include rain, fog drip, and various forms of snow, hail, and sleet. Canopy interception occurs when precipitation lands on plant foliage instead of falling to the ground and evaporating. Snowmelt is runoff produced by melting snow. Infiltration occurs when water flows from the surface into the ground. Subsurface flow refers to water that flows underground. Evaporation occurs when water in a liquid state changes to a gas. Sublimation occurs when water in a solid state (such as snow or ice) changes to water vapor without going through a liquid phase. Advection is the movement of water through the atmosphere. Condensation occurs when water vapor changes to liquid water. Transpiration occurs when water vapor is released from plants into the air.

Discuss the ideal gas law

The ideal gas law is used to explain the properties of a gas under ideal pressure, volume, and temperature conditions. It is best suited for describing monatomic gases (gases in which atoms are not bound together) and agese at high temperatures and low pressures. It is not well-suited for instances in which a gas or its components are close to their condensation point. All collisions are perfectly elastic and there are no intermolecular attractive forces at work. The ideal gas law is a way to explain and measure the macroscopic properties of matter. it can be derived from the kinetic theory of gases, which deals with the microscopic properties of matter. The equation for the ideal gas law is PV = nRT, where "P' is absolute pressure, "V" is absolute volume, and "T" is absolute temperature. R refers to the universal gas constant, which is 8.3145 j/mol Kelvin, and n is the number of moles.

Discuss the unique properties of water

The important properties of water are high polarity, hydrogen bonding, cohesiveness, adhesiveness, high specific heat, high latent heat, and high heat of vaporization. It is essential to life as we know it, as water is one of the main if not the main constituent of many living things. Water is a liquid at room temperature. The high specific heat of water means it resists the breaking of its hydrogen bonds and resists heat and motion, which is why it has a relatively high boiling point and high vaporization point. it also resists temperature change. Water is peculiar in that its solid state floats in its liquid state. Most substances are denser in their solid forms. Water is cohesive, which means it is attracted to itself. it is also adhesive, which means it readily attracts other molecules. If water tends to adhere to another substance, the substance is said to be hydrophilic. Water makes a good solvent. Substances, particularly those with polar ions and molecules, readily dissolve in water.

Explain the kinetic theory of gases.

The kinetic theory of gases assumes that gas molecules are small compared to the distances between them and that they are in constant random motion. The attractive and repulsive forces between gas molecules are negligible. Their kinetic energy does not change with time as long as the temperature remains the same. The higher the temperature is, the greater the motion will be. As the temperature of a gas increases, so does the kinetic energy of the molecules. In other words, gas will occupy a greater volume as the temperature is increased and lesser volume as the temperature is decreased. In addition, the same amount of gas will occupy a greater volume as the temperature increases, but pressure remains a constant. At any given temperature, gas molecules have the same average kinetic energy. THe ideal gas law is derived from the kinetic theory of gases.

Define inorganic compounds and describe their characteristics.

The main trait of inorganic compounds is that they lack carbon. Inorganic compounds include mineral salts, metals, and alloys, non-metallic compounds such as phosphorus, and metal complexes. A metal complex has a ventral atom (or ion) bonded to surrounding ligands (molecules or anions) The ligands sacrifice the donor atoms (in the form of at least one pair of electrons) to the central atom. Many inorganic compounds are ionic, meaning they form ionic bonds rather than share electrons. They may have high melting points because of this. They may also be colorful, but this is not an absolute identifier of an inorganic compound. Salts, which are inorganic compounds, are an example of inorganic bonding of cations and anions. Some examples of salts are magnesium chloride (MgCl2) and sodium oxide (Na2O). Oxides , carbonates, sulfates, and halides are classes of inorganic compounds. They are typically poor conductors, are very water soluble, and crystallize easily. Minerals and silicates are also inorganic compounds.

Explain magnetic fields as they relate to atomic structures.

The motions of subatomic structures (nuclei and electrons) produce a magnetic field. It is the direction of the spin and orbit that indicate the direction of the field. The strength of a magnetic field is known as the magnetic moment. As electrons spin and orbit a nucleus, they produce a magnetic field. Pairs of electrons that spin and orbit in opposite directions cancel each other out, creating a net magnetic field of zero. Materials that have an unpaired electron are magnetic. Those with a weak attractive force are referred to as paramagnetic materials, while ferromagnetic materials have a strong attractive force. A diamagnetic material has electrons that are paired and therefore does not typically have a magnetic moment. There are, however, some diamagnetic materials that have a weak magnetic field.

Discuss the features of the ocean floor

The ocean floor includes features similar to those found on land, such as mountains, plains, and canyons. The oceanic crust is a thin, dense layer that is about 10 km thick. The greatest volume of water is contained in the basins with lesser volumes that occupy the low-lying areas of the continents, which are known as the continental shelves. The continental slope connects the shelf to the ocean floor of the basin. The continental rise is slightly sloping area between the slope and the basin. A seamount is an undersea volcanic peak that rises to a height of at least 1,000 meters. A guyot is a seamount with a flat top. A mid-ocean ridge is a continuous undersea mountain chain. Sills are low parts of ridges separating ocean basins or other seas. Trenches are long, narrow troughs. Many isolated peaks and seamounts are scattered throughout the ocean basins, and interrupt ocean currents.

Discuss the physical properties of the ocean

The ocean is the salty body of water that encompasses the Earth. It has a mass of 1.4 x 10^24 grams. Geographically, the ocean is divided into three large oceans: the Pacific, Atlantic, and the Indian Oceans. There are also other divisions, such as gulfs, bays, and various types of seas, including Mediterranean and marginal seas. Ocean distances can be measured by latitude, longitude, degrees, meters, miles, an nautical miles. The ocean accounts for 70.8% of the surface of the Earth, amounting to 361,254,000 km2. The ocean's depth is greatest at Challenger Deep in the Mariana Trench. The ocean floor here is 10,924 meters below sea level. The depths of the ocean are mapped by echo sounders and satellite altimeter systems. Echo sounders emit a sound pulse from the surface and record the time it takes to return. Satellite altimeters provide better maps of the ocean floor.

Define and discuss the layers above the surface of the Earth other than the five main layers.

The ozone layer, although contained within the stratosphere, is determined by ozone (O3) concentrations. It absorbs the majority of the ultraviolet light from the Sun. The ionosphere is part of both the exosphere and the thermosphere. It is characterized by the fact that it is a plasma, a partially ionized gas in which free electrons and positive ions are attracted to each other, but are too energetic to remain fixed as a molecule. It starts at about 50 km above Earth's surface and goes to 1,000 km. It affects radio wave transmission and auroras. The ionosphere pushes against the inner edge of the Earth's magnetosphere, which is the highly magnetized, non-spherical region around the Earth. The homosphere encompasses the troposphere, stratosphere, and mesosphere. Gases in the homosphere are considered well mixed. In the heterosphere, the distance that particles can move without colliding is large. As result, gases are stratified according to their molecular weights. Heavier gases such as oxygen and nitrogen occur near the bottom of the heterosphere, while hydrogen, the lightest element, is found at the top.

Describe the periodic table and the basic layout

The periodic table groups elements with similar chemical properties together. the grouping of elements is based on atomic structure. it shows periodic trends of physical and chemical properties and identifies families of elements with similar properties. It is a common model for organizing and understanding elements. in the periodic table, each element has its own cell that includes varying amounts of information presented in symbol form about the properties of the element. Cells in the table are arranged in rows (periods) and columns (groups or families). At minimum, a cell for hydrogen, for example, which appears first in the upper left corner, includes an "H" and a "1" above the letter. Elements are ordered by atomic number, left to right, top to bottom.

Discuss how to identify rocks and minerals

The physical properties (as opposed ot chemical structures) used to identify minerals are hardness, luster, color, cleavage, streak, form (the external shape), and other special properties. Senses other than sight, such as touch, taste, and smell, may be used to observe physical properties. Hardness is the resistance a mineral has to scratches. The Mohs Hardness Scale is used to rate hardness from 1 to 10. Color can often not be determined definitively as some minerals can be more than one color. Luster is determined by reflected light. Luster can be described as metallic (shiny), sub-metallic (dull), non-metallic (vitreous, like glass) or earthy (like dirst or powder). Streak is the true color of the mineral in powdered form. It can be determined by rubbing the specimen across an unglazed porcelain tile. Fracture or cleavage is how a mineral reacts to stress, such as being struck with a hammer. Other properties that can be used to identify rocks and minerals include magnetism, a salty taste, or a pungent odor in a streak test.

Define pH and discuss the pH scale.

The potential of hydrogen (pH) is a measurement of the concentration of hydrogen ions in a substance in terms of the number of moles of H+ per liter of solution. A lower pH indicates a higher H+ concentration, while a higher pH indicates a lower H+ concentration. Pure water has a neutral pH, which is 7. Anything with a pH lower than water (less than 7) is considered acidic. Anything with a pH higher than water (greater than 7) is a base. Drain cleaner, soap, baking soda, ammonia, egg whites, and seawater are common bases. Urine, stomach acid, citric acid, vinegar, hydrochloric acid, and battery acids. A pH indicator is a substance that acts as a detector of hydrogen or hydronium ions. It is halochromic, meaning it changes color to indicate that hydrogen or hydronium ions have been detected.

Discuss the rate of evolution and how it is affected by the variability of a population.

The rate of evolution is affected by the variability of population. Variability increases the likelihood of evolution. Variability in a population can be increased by mutations, immigration, sexual reproduction ( as opposed to asexual reproduction), and size. Natural selection, emigration, and smaller populations can lead to decreased variability. Sexual selection affects evolutions. If fewer genes are available, it will limit the number of genes passed on to subsequent generations. Some animal mating behaviors are not as successful as others. A male that does not attract a female because of weak mating call or dull feathers, for example, will not pass on its genes. Mechanical isolation, which refers to sex organs that do not fit together very well, can also decrease successful mating.

Describe the components of the solar system

The solar system is a planetary system of objects that exist in an ecliptic plane. Objects orbit around and are bound by gravity to a star called the Sun. Objects that orbit around the Sun include: planets, dwarf planets, moons, asteroids, meteoroids, cosmic dust, and comets. The definition of planets has changed. At one time, there were nine planets in the solar system. There are now eight. Planetary objects in the solar system include four inner, terrestrial planets: Mercury, Venus, Earth, and Mars. They are relatively small, dense, rocky, lack rings, and have few or no moons. The four outer, or Jovian, planets are Jupiter, Saturn, Uranus, and Neptune, which are large and have low densities, rings, and moons. They are also known as gas giants. Between the inner and outer planets is the asteroid belt. Beyond Neptune is the Kuiper belt. Within these belts are five dwarf planets: Ceres, Pluto, Haumea, Makemake, and Eris.

Discuss the features and characteristics of the Sun

The sun is at the center of the solar system. it is composed of 70% hydrogen (H) an 28% helium (He). The remaining 2% is made up of metals. The sun is one of 100 billion stars in the Milky Way galaxy. Its diameter is 1,390,000 km, its mass is 1.989 x 10^30 kg, its surface temperature is 5,800 K, and its core temperature is 15,600,000 K The Sun represents more than 99.8% of the total mass of the solar system. At the core, the temperature is 15.6 million K, the pressure is 250 billion atmospheres, and the density is more than 150 times that of water. The surface is called the photosphere. The chromosphere live above this, and the corona, which extends millions of kilometers into space, is next. Sunspots are relatively cool regions on the surface with a temperature of 3,800 K. Temperatures in the corona are over 1,000,000 K. Its magnetosphere, or heliosphere, extends far beyond Pluto.

Explain the geometry of the Earth-Moon-Sun system

The system is responsible for eclipses. From Earth, the sun and the Moon appear to be about the same size. An eclipse of the Sun occurs during a new Moon, when the side of the Moon facing the Earth is not illuminate. The moon passes in front of the sun and blocks its view from earth. Eclipse do not occur every month because the orbit of the moon is at about a 5 degree angle to the plane of Earth's orbit. An eclipse of the moon happens during the full moon phase. the moon passes through the shadow of the Earth and blocks the sunlight from it reaching it, which temporarily causes darkness. During a lunar eclipse, there are two parts to the shadow. The umbra is the dark, inner region. The sun is completely blocked in this area. The penumbra is partially lighted area around the umbra. Earth's shadow is four times longer than the moon's shadow.

Explain the difference between inorganic and organic molecules

The term inorganic and organic have become less useful over time as their definitions have changed. Historically, inorganic molecules were defined as those of a mineral nature that were not created by biological processes. Organic molecules were defined as those that were produced biologically by a "life process" or "vital force". It was then discovered that organic compounds could be synthesized without a life process. Currently, molecules containing carbon are considered organic. Carbon is largely responsible for creating biological diversity, and is more capable than all other elements of forming large, complex, and diverse molecules of an organic nature. Carbon often completes its valence shell by sharing electrons with other atoms in four covalent bonds, which is also known as tetravalence.

Discuss the plate tectonic theory.

The theory of plate tectonic states that the lithosphere, the solid portion of the mantle and the Earth's crust, consists of major and minor plates. These plates are on top of and move with the viscous upper mantle, which is heated because of the convection cycle that occurs in the interior of the Earth. There are different estimates as to the exact number of major and minor plates. The number of major plates is believed to be between 9-15, and it is thought that there may be as many as 40 minor plates. The United States is atop the Northern American plate. The Pacific Ocean is atop the Pacific plate. The point at which these two plates slide horizontally along the San Andreas fault is an example of a transform plate boundary. The other two types of boundaries are divergent (plates that are spreading apart and forming new crust) and convergent (the process of subduction causes one plate to go under another). The movement of plates is what causes other features of the Earth's crust, such as mountains, volcanoes, and earthquakes.

Discuss the tilt of the Earth and its effect on seasonal variations in solar radiation.

The tilt of the Earth on its axis is 23.5 degrees. This tilt causes the seasons and affects the temperature because it affects the amount of Sun the area receives. When the Northern or Southern Hemispheres are tilted toward the Sun, the hemisphere tilted toward the sun experiences summer and the other hemisphere experiences winter. This reverses as the Earth revolves around the SUn. Fall and spring occur between the two extremes. The equator gets the same amount of sunlight every day of the year, about 12 hours, and doesn't experience seasons. Both poles have day during the winter when they are tilted away from the Sun and receive no daylight. The opposite effect occurs during the summer. THere are 24 hours of daylight and no night. THe summer solstice, the day with the most amount of sunlight, occurs on June 21st in the Northern Hemisphere and on December 21st in the Southern Hemisphere. The winter solstice, the day with the least amount of sunlight, occurs on the December 21st in the Northern Hemisphere and on June 21s in the Southern Hemisphere.

Describe the five main atmospheric layers and discuss their temperatures

The troposphere, stratosphere, mesosphere, thermosphere, and exosphere. Between each pair of layers is a transition layer called a pause. The troposphere includes the tropopause, which is the transitional layer of the stratosphere. Energy from Earth's surface is transferred to the troposphere. Temperature decreases with altitude in this layer. In the stratosphere, the temperature is inverted, meaning that it increases with altitude. THe stratosphere includes the ozone layer, which helps block ultraviolet light from the Sun. The stratopause is the transitional layer to the mesosphere. The temperature of the mesosphere decreases with height. It is considered the coldest place on Earth, and has an average temperature of -85 degrees Celsius. Temperature increases with altitude in the thermosphere, which includes the thermopause. Just past the thermosphere is the exobase, the base layer of the exosphere. Beyond the five main layers are the ionosphere, homosphere, heterosphere, and magnetosphere.

Explain the origin of the universe.

The universe can be said to consist of everything and nothing. The universe is the source of everything we know about space, matter, energy, and time. There are likely still phenomena that have yet to be discovered. The universe can also be thought of as nothing, since a vast portion of the known universe is empty space. It is believed that the universe is expanding. The Big Bang theory, which is widely accepted among astronomers, was developed to explain the origin of the universe. There are other theories regarding the origin of the universe, such as the Steady-State theory and the Creationist theory. The Big Bang theory states that all the matter in the universe was once in one place. THis matter underwent a huge explosion that spread the matter into space. Galaxies formed from this material and the universe is still expanding.

Discuss some applications that make use of the properties of light.

The various properties of light have numerous real life applications. For example, polarized sunglasses have lenses that help reduce glare, while non-polarized sunglasses have lenses that reduce the total amount of light that reaches the eyes. Polarized lenses consist of a chemical film of molecules aligned in parallel. This allows the lenses to block wavelengths of light that are intense, horizontal, and reflected from smooth, flat surfaces. The "fiber" in fiber optics refers to a tube or pipe that channels light. Because of the composition of the fiber, light can be transmitted a greater distances before losing the signal. The fiber consists of a core, cladding, and a coating. Fibers are bundled, allowing for the transmission of large amounts of data.

Discuss natural satellites in the solar system

There are about 335 moons, or satellites, that orbit the planets and objects in the solar system. Many of these satellites have been recently discovered, a few are theoretical, some are asteroid moons (moons orbiting asteroids), some are moonlets (small moons), and some are moons of dwarf planets and objects that have not been definitively categorized, such as trans-Neptunian objects. Mercury and Venus do not have any moons. There are several moons larger than the dwarf planet Pluto and two larger than Mercury. Some consider the Earth and Moon a pair of double planets rather than a planet and a satellite. Some satellites may have started out as asteroids. They were eventually captured by a planet's gravity and become moons.

Discuss the life cycle of a star

There are different life cycle possibilities for stars after they initially form and enter into the main sequence stage. Small, relatively cold red dwarfs with relatively low masses burn hydrogen slowly, and will remain in the main sequence for hundreds of billions of years. Massive, hot supergiants will leave the main sequence after just a few million years. The Sun is a mid-sized star that may be in the main sequence for 10 billion years. After the main sequence, the star expands to become a red giant. Depending upon the initial mass of the star, it can become a black dwarf (from a medium-sized star), and then a small, cooling white dwarf. Massive stars become red supergiants (and sometimes blue supergiants), explode in a supernova, and then become neutron stars. The largest stars can become black holes.

Discuss some of the limitations of space exploration.

There are many limitations of space exploration. The main limitation is knowledge. Space exploration is currently time-consuming, dangerous, and costly. Manned and unmanned missions, even within the solar system, take years of planning and years to complete. The associated financial costs are great. Interstellar travel and intergalactic is not yet realistically feasible. Technological advances are needed before these types of missions can be carried out. By some estimates, it would take more than 70 years to travel to Proxima Centauri (the nearest star) using the fastest rocket technology available. It would take much longer using less advanced technologies. Space travel is dangerous for many reasons. Rocket fuel is highly explosive. Non-Earth environments are uninhabitable for humans. Finally, astronauts are exposed to larger than usual amounts of radiation.

List the number of electron shells and identify their corresponding subshells, their names, their maximum number of electrons, and their atomic orbitals.

There are seven electron shells. One is closet to the nucleus and seven is the farthest away. Electron shells can also be identified with the letters K, L, M, N, O, P, and Q. Traditionally, there were four subshells identified by the first letter of their descriptive name: s (sharp) , p (principal), d (diffuse), and f (fundamental). The maximum number of electrons for each subshell is as follows: s is 2, p is 6, d is 10, and f is 14. Every shell has an s subshell, the second shell and those above also have a p subshell, the third shell and those above have a d subshell, and so on. Each subshell contains atomic orbitals, which describes the wave-like characteristics of an electron or a pair of electrons expressed as two angles and the distance from the nucleus. Atomic orbital is a concept used to express the likelihood of an electron's position in accordance with the idea of wave-particle duality.

Define velocity and acceleratrion

There are two types of velocity to consider: average velocity and instantaneous velocity. Unless an object has a constant velocity or we are explicitly given an equation for the velocity, finding the instantaneous velocity of an object requires the use of calculus. If we want to calculate the average velocity of an object we need to know two things: the displacement, or the distance it has covered, and the time it took to cover this distance. The formula for average velocity is simply the distance traveled divided by the time required. In other words, the average velocity is equal to the change in position divided by the change in time. Average velocity is a vector and will always point in the same direction as the displacement vector ( since time is scalar and always positive). Acceleration is the change in the velocity of an object. One most test questions, the acceleration will be a constant value. Like position and velocity, acceleration is a vector quantity and will therefore have both magnitude and direction.

Define transpiration, respiration, and phylogenetic.

Transpiration is the movement of water through a vascular plant. It is also the method by which water is evaporated out of plants. Transpiration mainly happens during the process of photosynthesis, when water and minerals travel up through the xylem and are used and water is released through stomata (flattened oval-shaped openings). During transpiration, water is drawn up a plant. This process also helps cool leaves. Respiration: this refers to the process of metabolizing sugars to provide plants with the energy they need for growth and reproduction. The chemical equation is C6H12O6 + 6O2--> 6C)2 +6H2O + energy. During the process of respiration, sugars are burned, energy is released, oxygen is used, and water and carbon dioxide are produced. Respiration can occur as a light or dark reaction. Phylogenetic: this refers to organisms that are related because of their evolutionary history.

Define organic compounds and identify their characteristics

Two of the main characteristics of organic compounds are that they include carbon and are formed by covalent bonds. Carbon can form long chains, double and triple bonds, and rings. While inorganic compounds tend to have high melting points, organic compounds tend to melt at temperatures below 300 degrees Celsius. They also tend to boil, sublimate, and decompose below this temperature. Unlike inorganic compounds, they are not very water soluble. Organic molecules are organized into functional groups based on their specific atoms, which helps determine how they will react chemically. A few groups are alkanes, birton, alkenes, sulfides, amines, and carbolic acids. The hydroxyl group (-OH) consists of alcohols. These molecules are polar, which increases their solubility. By some estimates, there are more than 16 million organic compounds.

Define uniformitarianism, catastrophism, and superposition.

Uniformitarianism: also known as gradualism, is the belief among modern geologists that the forces, processes, and laws that we see today have existed throughout geologic time. It involves the belief that the present is the key to the past, and that relatively slow processes have shaped the geological features of Earth. Catastrophism: this is the belief that the Earth was shaped by sudden, short-term catastrophic events. Superposition: in geology, and in the field of stratigraphy in particular, the law of superposition is that underground layers closer to the surface were deposited more recently.

Differentiate between vascular and nonvascular plants

Vascular plants have vascular tissue in the form of xylem and phloem. These make up the parts of the plants, such as the roots, stems, and leaves that are involved in transporting minerals and water throughout the plant. This capability enables vascular plants to grow tall. Food/energy that is converted by photosynthesis in the leaves is brought down to the roots, while water is brought to the top of the plant. Nonvascular (or avascular) plants lack true leaves, stems, and roots. Nonvascular plants do not develop vascular tissue, such as xylem and phloem. They tend to be small, and individual cells are adjacent to their environment.

Define and briefly discuss the follwoing wave types: longitudinal, shear, surface, and plate.

Waves are divided into types based on the direction of particle motion in a medium and the direction of wave propagation. Longitudinal wave: are waves that travel in the same direction as the particle movement. They are sometimes called pressure, compressional, or density waves. Longitudinal sound waves are the easiest to produce and have the highest speed. A longitudinal wave consists of compressions and rarefactions, such as those seen by expanding and collapsing a slinky toy. Shear or transverse waves: are waves that move perpendicular to the direction of the particle movement. For example, if the particles in a medium move up and down, a transverse wave will move forward. Transverse waves are possible only in solids and are slower than longitudinal waves. Surface (circular) waves: these waves travel at the surface of a material and move in elliptical orbits. They are a little slower than shear waves. Plate waves: these waves move in elliptical orbits and only occur in very thing pieces of material.

Discuss wave interactions

Waves can be in phase or out of phase, which is similar to the concept of being in sync or out of sync. For example, it two separate waves originate from the same point and the peaks (crests) and valleys (troughs) are exactly aligned, they are said to be in phase. If the peak of a wave aligns with the valley of another wave, they are out of phase. When waves are in phase their displacement is doubled. If they are out of phase they cancel each other out. If they are somewhere in between being completely in phase and completely out of phase, the wave interaction is a wave that is the sum of the amplitudes of all points along the wave. If the waves originate from different points, the amplitude of particle displacement is the combined sum of the particle displacement amplitude of each individual wave.

Provide a brief overview of waves and identify the major types of waves

Waves have energy and can transfer energy when they interact with matter. Although waves transfer energy, they do not transport matter. They are a disturbance of matter that transfers energy from on particle to an adjacent particle. there are many types of waves, including sound, seismic, water, light, micro, and radio waves. The two basic categories of waves are mechanical and electromagnetic. Mechanical waves are those that transmit energy through matter. Electromagnetic waves can transmit energy through a vacuum. A transverse wave provides a good illustration of the features of a wave, which include crest, troughs, amplitude, and wavelength.

Discuss the formation of beaches and the different types of beaches

Weathering erodes the parent material of beaches, rock, and soil, into sand, which is typically quartz. Other parts of the soil such as clay and silt are deposited in areas of the continental shelf. The larger sand particles get deposited in the form of a beach. This includes a near shore, which is underwater, a fore shore, the area typically considered the beach, and a back shore. The offshore starts about 5 meters from the shoreline and extends to about 20 meters. The beach also includes wet and dry parts and a fore dune and rear dune. Waves typically move sand from the sea to the beach, and gravity and wave action move it back again. Wind gradually pushes sand particles uphill in a jumping motion called saltation. Sand stays deposited in the form of dunes and the dunes appear as if they roll backward. Storms can bot herode a beach and provide additional deposition.

Discuss the structure of the universe.

What can be seen of the universe is believed to be at least 93 billion light years across. To put this into perspective, the Milky Way galaxy is about 100,000 light years across. Our view of matter in the universe is that it forms into clumps. Matter is organized into stars, galaxies, clusters of galaxies, superclusters, and the Great Wall of galaxies. Galaxies consist of starts, come with planetary systems. Some estimates state that the universe is about 13 billion years old. It is not considered dense, and is believed to consists of 73 percent dark energy, 23 percent cold dark matter, and 4 percent regular matter. Cosmology is the study of the universe. Interstellar medium (ISM) is the gas and dust in the interstellar space between a galaxy's stars.

Explain what happens when light encounters a solid object.

When light waves encounter an object, they are either reflected, transmitted, or absorbed. If the light is reflected from the surface of the object, the angle at which it contacts the surface will be the same as the angle at which it leaves, on the other side of the perpendicular. If the ray of light is perpendicular to the surface, it will be reflected back in the direction from which it came. When light is transmitted through the object, its direction may be altered upon entering the object. This is known as refraction. When light waves are refracted, or bent, an image can appear distorted. THe degree to which the light is refracted depends on the speed at which light travels in the object. Light that is neither reflected nor transmitted will be absorbed by the surface and stored as heat energy. Nearly all instances of light hitting an object will involve a combination of two or even all three of these.

List some properties of acids.

When they are dissolved in aqueous solutions, some properties of acids are that they conduct electricity, change blue litmus paper to red, have a sour taste, react with bases to neutralize them, and react with active metals to free hydrogen. A weak acid is one that does not donate all of its protons or disassociate completely. Strong acids include hydrochloric, hydriodic, hydrobromic, perchloric, nitric, and sulfuric. They ionize completely. Superacids are those that are stronger than 100 percent sulfuric acid. THey include fluoroantimonic, magic, and perchloric acids. Acids can be used in pickling, a process used to remove rust and corrosion from metals. They are also used as catalysts in the processing of minerals and the production of salts and fertilizers. Phosphoric acid is added to sodas and other acids are added to food as preservatives or to add taste.

List some properties of bases.

When they are dissolved in aqueous solutions, some properties of bases are that they conduct electricity, change red litmus paper to blue, feel slippery, and react with acids to neutralize their properties. A weak base is one that does not completely ionize in an aqueous solution, and usually has a low pH. Strong bases can free protons in very weak acids. Examples of strong bases are hydroxide compounds such as potassium, barium, and lithium hydroxide. Most are in the first and second groups of the periodic table. A superbase is extremely strong compared to sodium hydroxide and cannot be kept in an aqueous solution. Superbases are organized into organic, organometallic, and inorganic classes. Bases are used as insoluble catalysts in heterogeneous reactions and as catalysts in hydrogenation.

Discuss wave interference in more detail, focusing on constructive and destructive interference.

When waves traveling in the same medium interact, it is known as wave intergerence. While a single wave generally remains the same in terms of waveform, frequency, amplitude, and wavelength, several waves traveling through particles in a medium take on a more complicated appearance after they interact. The final properties of a wave are dependent on many factors, such as the points of origin of waves and whether they are in phase, out of phase, or somewhere in between. Constructive interference refers to what happens when two crests or two troughs of a wave meet. The resulting amplitude of the crest or trough is doubled. Destructive interference is what happens when the crest of one wave and the trough of another that are the same shape meet. When this occurs, the two waves cancel each other out. An example of destructive interference is when two unlike sound waves reduce the volume of the sound.

Identify the causes of winds and global wind belts.

Winds are the result of air moving by convection. Masses of warm air rise, and cold air sweeps into their place. The arm air also moves, cools, and sinks. The term "prevailing wind" refers to the wind that usually blows in an area in a single direction. Dominant winds are the winds with the highest speeds. Belts or bands that run latitudinally and blow in a specific direction are associated with convection cells. Hadley cells are formed directly north and south of the equator. THe Farrell cells occur at about 30 degrees to 60 degrees. The jet stream runs between the Farrell cells and the polar cells. At mid latitudes, the direction is westerly. From the North Pole to the south, the surface winds are Polar High Easterlies, Subpolar Low Westerlies, Subtropical High or Horse Latitudes, North- East Trade winds, Equatorial Low or Doldrums, South-East Trades, Subtropical High or Horse Latitudes, Subpolar Low Easterlies, and Polar HIgh.

Define work

Work can be thought of as the amount of energy expended in accomplishing some goal. The simplest equation for mechanical work (W) is W=Fd, where F is the force exerted and d is the displacement of the object on which the force is exerted. This equation requires that the force be applied in the same direction as the displacement. If this is not the case, then the work may be calculated as W=Fd cos, where is the angle between the force and the displacement vectors. If force and displacement have the same direction, then work is positive; if they are in opposite directions, then work is negative; and if they are perpendicular, the work done by the force is zero.

Discuss the concepts community , species diversity, and niche. Define biome, biotic, ecology, and ecosystem

A community is any number of species interacting within a given area. A niche is the role of a species within a community. Species diversity refers to the number of species within a community and their populations. A biome refers to an area in which species are associated because of climate. The six major biomes in North America are desert, tropical rain forest, grassland, coniferous forest, deciduous forest, and tundra. Biotic factors are the living factors, such as other organisms, that affect a community or population. Abiotic factors are nonliving factors that affect a community or population, such as facets of the environment. Ecology: the study of plants, animals, their environments, and how they interact. Ecosystem: a community of species and all of the environmental factors that affect them.

Discuss food chains and biomagnification.

A food chain is a linking of organisms in a community that is based on how they use each other as food sources. Each link in the chain consumes the link above it and is consumed by the link below it. The exceptions are the organism at the top of the food chain and the organism at the bottom. Biomagnification (bioamplification): refers to an increase in concentration of a substance within a food chain. Examples are pesticides or mercury. Mercury is emitted from coal-fired power plants and gets into the water supply, where it is eaten by a fish. A larger fish eats smaller fish, and humans eat fish. The concentration of mercury in humans has now risen. Biomagnification is affected by the persistence of a chemical, whether it can be broken down and negated, food chain energetics, and whether organisms can reduce or negate the substance.

Discuss food webs, energy flow, and trophic levels.

A food web consists of interconnected food chains in a community. THe organisms can be linked to show the direction of energy flow. Energy flow in this sense is used to refer to the actual caloric flow through a system from trophic level to trophic level. Trophic level refers to a link in a food chain or a level of nutrition. THe 10% rule is that from trophic level to tevel, about 09% of the energy is lost (in the form of heat, for example). The lowest trophic level consists of primary producers (usually plants), then primary consumers, then secondary consumers, and finally tertiary consumers (large carnivores). The final link is decomposers, which break down the consumers at the top. Food chains usually do not contain more than six links. These links may also be referred to as ecological pyramids.

Define and discuss gene, genotype, phenotype, and allele

A gene is a portion of DNA at identifies how traits are expressed and passed on in an organism. A gene is part of the genetic code. Collectively, all genes form the genotype of an individual. The genotype includes genes that may not be expressed, such as recessive genes. The phenotype is the physical, visual manifestation of genes. it is determined by the basic genetic information and how genes have been affected by their environment. An allele is a variation of a gene. Also known as a trait, it determines the manifestation of a gene. This manifestation results in a specific physical appearance of some facet of an organism, such as eye color or height. For example the genetic information for eye color is a gene. The gene variations responsible for blue, green, brown, or black eyes are called alleles. Locus (plural loci) refers to the location of a gene or alleles.

Define organism and microbe. Differentiate between a unicellular and multicellular organism

An organism is a living thing. A unicellular organism is an organism that has only one cell. Examples of unicellular organisms are bacteria and paramecium. A multicellular organism is one that consists of many cells. Humans are a good example. By some estimates, the human body is made up of billions of cells. Others think the human body has more than 75 trillion cells. The term microbe refers to small organisms that are only visible through a microscope. Examples include viruses, bacteria, fungi, and protozoa. Microbes are also referred to as microorganisms, and it is these that are studied by microbiologists. Bacteria can be rod shaped, round (cocci) or spiral (spirilla). These shapes are used to differentiate among types of bacteria. Bacteria can be identified by staining them. THis particular type of stain is called a gram stain. If bacteria are gram-positive, they aboard the stain and become purple. If bacteria are gram-negative, they do not absorb the stain and become a pinkish color.

Identify the four main animal tissue types and their characteristics.

Animals have four main tissues types: epithelial, connective, muscle, and bone. Epithelial tissue is found on body surfaces (like skin) and lining body cavities (like stomach). Its function is to form and protect various glands. The three types of epithelial tissue are squamous (flattened), cuboidal (cube-shaped), and columnar (elongated). It can be further classified as simple (a single- layer) or stratified (more than one layer). Epithelial cells move substances in, around, and out of the body. They can also have protective and secretory functions. Glands comprised of epithelial tissue can be unicellular or multicellular. Connective tissue is used to bind, support, protect, form blood, store fat, and fill space. The two kinds of connective tissue are loose and fibrous. In the human body, cartilage, bone, tendons, ligaments, blood, and protective layers on muscle, nerve, and blood vessels are types of connective tissue. THe three types of muscle tissue are skeletal (striated), smooth, and cardiac.

Discuss classifications of animals according to their food sources and food requirements

As heterotrophs, animals can be further classified as carnivores, herbivores, omnivores, and parasites. Predation refers to a predator that feeds on another organism, which results in its death. Detritivory refers to heterotrophs that consume organic dead matter. Carnivores are animals that are meat eaters. Herbivores are plant eaters, and Omnivores eat both meat and plants. A parasite's food source is its host. A parasite lives off a host, which does not benefit from the interaction. Nutrients can be classified as carbohydrates, fats, fiber, minerals, proteins, vitamins,and water. Each supply a specific substance required for various species to survive, grow, and reproduce. A calorie is a measurement of heat energy. It can be used to represent both how much energy a food can provide and how much energy an organism needs to live.

Differentiate among the reproductive systems in animals

Based on whether or not and when an organism uses meiosis or mitosis, the three possible cycles of reproduction are haplontic, diplontic, and haplodiplontic. Gungi, green algae, and protozoa are haplontic. Animals and some brown algae and fungi are diplontic. Plants and some fungi are haplodiplontic. Diplontic organisms, like multicelled animals, have a dominant diploid life cycle. The haploid generation is simply the egg and sperm. Monoecious species are bisexual ( hermaphroditic). In this case, the individual has both male and female organs: sperm-bearing testicles and egg-bearing ovaries. Hermaphroditic species can self fertilize. Some worms are hermaphroditic. Cross fertilization is when individuals exchange genetic information. Most animals species are dioecious, meaning individuals are distinctly male or female.

Discuss biochemical cycles. Define mimicry.

Biochemical cycles are how chemical elements required by living organisms cycle between living and nonliving organisms. Elements that are frequently required are phosphorus sulfer, oxygen, carbon, gaseous nitrogen, and water. Elements can go through gas cycles, sedimentary cycles, or both. elements circulate through the air in a gas cycle and from land to water in a sedimentary one. Mimicry is an adaptation developed as a response to predation. It refers to an organism that has a similar appearance to another species, which is meant to fool the predator into thinking the organism is more dangerous than it really is. Two examples are the drone fly and the io moth. The fly looks like a bee, but cannot sting. The io moth has marking on its wings that make it look like an owl. The moth can startle predators and gain time to escape. Predators can also use mimicry to lure their prey.

Differentiate among the different reproduction methods used by various categories of plants.

Bryophytes are seedless plants. They include liverworts, hornworts, and mosses. They use spores that form into gametophytes to reproduce. Sperm are flagellated, meaning they require at least some water to wim to the egg. Some bryophytes are plants that are one sex or the other, but other bryophytes have both sexes on the same plant. Ferns also have flagellated sperm and require water for the same reason as bryophytes. Both ferns and bryophytes undergo alternation of generations. These plants spend about half their reproductive cycles as sporophytes, making haploid spores through meiosis during this stage. The other half of the cycle is spent as a haploid gametophyte. At this point, male and female gametes join to form one zygote. Seed plants use seeds to reproduce. Flowering plants use flowers and seeds.

Define the following terms as they relate to cell division: chromatids, gametes, and haploid/diploid.

Cell division is performed in organisms so they can grow and replace cells that are old, worn out, or damaged. Chromatids: During cell division, the DNA is replicated, and chromatids are the two identical replicated pieces of chromosome that are joined at the centromere to form and "x". Gametes: These are cells used by organisms to reproduce sexually. Gametes in humans are haploid, meaning they contain only half the genetic information of the organism (23 chromosomes). Other human cells contain all 46 chromosomes. Haploid/diploid: Haploid means there is one set of chromosomes. Diploid means there are two sets of chromosomes (one set from each parent).

Define and describe the following structures that are unique to plant cells: cell wall, chloroplast, plastid, and plasmodesmata.

Cell wall: made of cellulose and composed of numerous layers, the cell wall provides plants with a sturdy barrier that can hold fluid within the cell. The cell wall surrounds the cell membrane Chloroplast: this is a specialized organelle that plant cells use for photosynthesis, which is the process plants use to create food energy from sunlight. Chloroplasts contain chlorophyll, which has a green color. Plastid: this is a membrane-bound organelle found in plant cells that is used to make chemical compounds and store food. It can also contain pigments used during photosynthesis Plastids can develop into more specialized structures such as chloroplasts, chromoplasts (make and hold yellow and orange pigments), amyloplasts (store starch), and leucoplasts (lack pigments, but can become differentiated). Plasmodesmata (singular plasmodesma): these are channels between the cell walls of plants cells that allow for transport between cells.

Define and discuss cellular respiration

Cellular respiration refers to a set of metabolic reactions that convert chemical bonds into energy stored in the form of ATP. Respiration includes many oxidation and reduction reactions that occur thanks to the electron transport system within the cell. Oxidation is a loss of electrons and reduction is a gain of electrons. Electrons in C-H (carbon/hydrogen) and C-C(carbon/carbon) bonds are donated to oxygen atoms. Processes involved in cellular respiration include glycolysis, the Krebs cycle, the electron transport chain, and chemiosmosis. The two forms of respiration are aerobic and anaerobic. Aerobic respiration is very common, and oxygen is the final electron acceptor. In anaerobic respiration, the final electron acceptor is not oxygen. Aerobic respiration results in more ATP than anaerobic respiration. Fermentation is another process by which energy is converted.

Define and describe the following structures that are unique to animal cells: centrosome, centriole, lysosome, cilia, and flagella.

Centrosome: this is comprised of the pair of centrioles located at right angles to each other and surrounded by protein. The centrosome is involved in mitosis and the cell cycle. Centriole: these are cylinder-shaped structures near the nucleus that are involved in cellular division. Each cylinder consists of nine groups of three microtubules. Centrioles occur in pairs. Lysosome: this digests proteins, lipids, and carbohydrates, and also transports undigested substances to the cell membrane so they can be removed. The shape of lysosome depends on the material being transported. Cilia (singular cilium): these are appendages extending from the surface of the cell, the movement of which causes the cell to move. They can also result in fluid being moved by the cell. Flagella: these are tail-like structures on cells that use whip-like movements to help the cell move. They are similar to cilia, but are usually longer and not as numerous. A cell usually only has one or a few flagella.

Identify the major plant phyla (divisions) and their characteristics.

Chlorophyta are green algae. Bryophytes are nonvascular mosses and liverworts. They have root-like parts called rhizoids. Since they do not have the vascular structures to transport water, they live in moist environments. Lycophyta are club mosses. They are vascular plants. They use spores and need water to reproduce. Equisetopsida (sphenophyta- are horsetails. Like lycophyta, they need water to reproduce with spores. They have rhizoids and needle-like leaves. The pteridophytes (filicopsida) are ferns. They have stems (rhizomes). Spermatopsida are the seed plants. Gymnosperms are a conifer, which means they have cones with seeds that are used in reproduction. Plants with seeds require less water. Cycadophyta are cone-bearing and look like palms. Gnetophyta are plants that live in the desert. Coniferophyta are pine trees, and have both cones and needles. Ginkgophyta are ginkos. Anthophyta is the division with the largest number of plant species, and includes flowering plants with true seeds.

Define and discuss codons.

Codons are groups of three nucleotides on the messenger RNA, and can be visualized as three rungs of a ladder. A codon has the code for a single amino acid. There are 64 codons but 20 amino acids. More than one combination, or triplet, can be used to synthesize the necessary amino acids. For example, AAA (adenine-adenine-adenine), or AAG (adenine-adenine-guanine) can serve as codons for lysine. These groups of three occur in strings, and might be thought of as frames. For example, AAAUCUUCGU, if read in groups of three from the beginning, would be AAA,UCU,UCG, which are codons for lysine, serine, and serine, respectively.If the same sequence was read in groups of three starting from the second position, the groups would be AAU (asparagine), CUU (proline), and so on. The resulting amino acids would be completely different. For this reason, there are start and stop codons that indicate the beginning and ending of a sequence (or frame) AUG (methionine) is the start codon. UAA, UGA, and UAG, are also known as ocher, opal, and amber, respectively, are stop codons.

Define and discuss codons

Codons are groups of three nucleotides on the messenger RNA, and can be visualized as three rungs of a ladder. A condon has the code for a single amino acid. There are 64 codons but 20 amino acids. More than one combination, or triplet, can be used to synthesize the necessary amino acids. For example, AAA (adenine-adenine- adenine) or AAG (adenine-adenine-guanine) can serve as codons for lysine. These groups of three occur in strings, and might be thought of as frames. For example, AAAUCUUCGU, if read in groups of three from the beginning, would be AAA, UCU, UCG, which are codons for lysine, serine, and serine, respectively. If the same sequence was read in groups of three starting from the second position, the groups would be AAU (asparagine), CUU (proline) and so on. The resulting amino acids would be completely different. For this reason, there are start and stop codons that indicate the beginning and the ending of a sequence (or frame). AUG (methionine) is the start codon. UAA, UGA, and UAG, also known as ocher, opal, and amber, respectively are stop codons.

List some facts about the digestive and respiratory systems, including hormonal control mechanisms, parts of the systems, their locations, and their functions.

Digestive: this includes the mouth, pharynx, esophagus, stomach, intestines, rectum, anal canal, teeth, salivary glands, tongue, liver, gallbladder, pancreas, and appendix. THe system helps change food into a form that the body can process and use for energy and nutrients. Food is eventually eliminated as solid waste. Digestive processes can be mechanical, such as chewing food and churning it in the stomach, and chemical, such as secreting hydrochloric acid to kill bacteria and converting protein to amino acids. The overall system converts large food particles into molecules so the body can use them. the small intestine transports the molecules to the circulatory system. The large intestine absorbs nutrients and prepares the unused portions of food for elimination. Respiratory: this includes the nose, pharynx, larynx, trachea, bronchi, and lungs. It is involved in gas exchange, which occurs in the alveoli. Fish have gills instead of lungs.

Define the process of erosion.

Erosion is the wearing away of rock materials from the Earth's surface. Erosion can be classified as natural geologic erosion and erosion due to human activity. Natural geologic erosion occurs due to weathering and gravity. Factors involved in natural geologic erosion are typically long term forces. Human activity such as development, farming, and deforestation occurs over shorter periods of time. Soil, which supports plant growth, is the topmost layer of organic material. One type of erosion is sheet erosion, which is the gradual and somewhat uniform removal of surface soil. Rills are small rivulets that cut into soil. Fullies are rills that have become enlarged due to extended water run-off. Sand Blows are caused by wind blowing away particles. Negative effects of erosion include sedimentation in rivers, which can pollute water and damage ecosystems. Erosion can also result in the removal of topsoil, which destroys crops and prevents plants from growing. This reduces food production and alters ecosystems.

List some facts about the excretory, immune, and reproductive systems, including hormonal control mechanisms, parts of the systems, their locations, and their functions.

Excretory: this includes the kidneys, ureters, bladder, and urethra. The excretory system helps maintain the amount of fluids in the body. Wastes from the blood system and excess water are removed in urine. The system also helps remove solid waste. Immune: this includes the lymphatic system, lymph nodes, lymph vessels, thymus, and spllen. Lymph fluid is moved throughout the body by lymph vessels that provide protection against disease. This system protects the body from external intrusions, such as microscopic organisms and foreign substances. It can also protect against some cancerous cells. Reproductive: in the male, this system includes the testes, vas deferens, urethra, prostate, penis, and scrotum. In the female, this system includes the ovaries, fallopian tubes (oviduct and uterine tubes), cervix, uterus, vagina, vulva, and mammary glands. Sexual reproduction helps provide genetic diversity as gametes from each parent contribute half the DNA to the zygote offspring. The system provides a method of growth and development of the embryo. Hormones involved are testosterone, interstitial cell stimulating hormones (ICSH), luteinizing hormone (LH), follicle stimulating hormone (FSH), and estrogen. Estrogens secreted from the ovaries include estradiol, estrone, and estriol. They encourage growth, among other things. Progesterone helps prepare the endometrium for pregnancy.

Define extrinsic and discuss hormones. Differentiate between endoskeletons and exoskeletons, vertebrates and invertebrates

Extrinsic refers to homeostatic systems that are controlled from outside the body. In higher animals, the nervous system and endocrine system help regulate body functions by responding to stimuli. Hormones in animals regulate many processes, including growth, metabolism, reproduction, and fluid balance. THe names of hormones tend to end in "-one." Endocrine hormones are proteins or steroids. Steroid hormones (anabolic steroids) help control the manufacture of protein in muscles and bone. Invertebrates do not have a backbone, whereas vertebrates do. The great majority of animal species (an estimated 98%) are invertebrates, including worms, jellyfish, mollusks, slugs, insects, and spiders. They comprise 30 phyla in all Vertebrates belong to the phylum chordata. The vertebrate body has two cavities. The thoracic cavity holds the heart and lungs and the abdominal cavity holds the digestive organs. Animals with exoskeletons have skeletons on the outside. Examples include crabs, scorpions, and insects. Animals with endoskeletons have skeletons on the inside. Examples are humans, tigers, birds, and reptiles. All vertebrates have endoskeletons.

Describe the sexual parts of flowering plants in detail

Flowering plants can be categorized sexually according to which organs they have. Flowers can be bisexual or unisexual. Species can be dioecious, which means male and female flowers are contained on different individual plants. Monoecious means that both male and female flowers are on one individual. Bisexual flowers are those that have all of the following: sepal, petal, stamen, and pistil. If they have all of these parts, they are considered complete. They have both the male stamen and the female counterpart, the pistil. Unisexual flowers only have a pistil or stamen. Not both. Incomplete flowers do not have a ll four parts. THe flower rests upon a pedicel and is contained with the receptacle. The carpal is made up of the stigma at the tip, a style, and the ovary at the base. The ovary contains the ovules (eggs). Carpels are sometimes formed as a single pistil. The stamen includes the anther and the filament, and produces the male pollen.

Differentiate among the different types of mutations

Gene disorders are a result of DNA mutations. DNA mutations lead to unfavorable gene disorders, but also provide genetic variability. THis diversity can lead to increased survivability of a species. Mutations can be neutral, beneficial, or harmful. Mutations can be hereditary, meaning they are passed from parent to child. Polymorphism refers to differences in humans, such as eye and hair color, that may have originally been the result of gene mutations, but are not part of the normal variation of the species. Mutations can be de novo, meaning they happen either only in sex cells or shortly after fertilization. They can also be acquired, or somatic. These are the kinds that happen as a result of DNA changes due to environmental factors or replication errors. Mosaicism is when a mutation happens in a cell during an early embryonic stage. The result is that some cells will have the mutation and some will not.

Discuss the concept of dominant and recessive

Gene traits are represented in pairs with an upper case letter for the dominant trait (A) and a lower case letter for the recessive trait (a). Genes occur in pairs (AA, Aa, or aa). There is one gene on each chromosome half supplied by each parent organism. Since half the genetic material is from each parent, the offspring's traits are represented as a combination of these. A dominant trait only requires one gene of a gene pair for it t o be expressed in a phenotype, whereas a recessive requires both genes in order to be manifested. For example, if the mother's genotype is Dd and the father's is dd, the possible combinations are Dd and dd. the dominant trait will be manifested if the genotype is dd. Both DD and dd are homozygous pairs. Dd is heterozygous.

Define monohybrid and hybrid crosses

Genetic crosses are the possible combinations of alleles, and can be represented using Punnett squares. A monohybrid cross refers to a cross involving only one trait. Typically, the ratio is 3:1 (DD, Dd, Dd, dd) which is the ratio of dominant gene manifestation to recessive gene manifestation. This ratio occurs when both parents have a pair of dominant genes (DD) and the other has a pair of recessive (dd) genes, the recessive trait cannot be expressed in the next generation because the resulting crosses all have the Dd genotype. A dihybrid cross refers to one involving more than one trait, which means more combinations are possible. The ratio of genotypes for a dihybrid cross is 9:3:3:1 when the traits are not linked. The ratio for incomplete dominance is 1:2:1, which corresponds to dominant, mixed, and recessive phenotypes.

Define homeostasis and discuss negative and positive feedback loops

Homeostasis is the ability and tendency of an organism, cell, or body to adjust to environmental changes to maintain equilibrium. One way an organism, such as a human body, can maintain homeostasis is through the release of hormones. Some hormones work in pairs. When a condition reaches an upper limit, a hormone is released to correct the condition. When a condition reaches the other end of the spectrum, another hormone is released. Hormones that work in this way are termed antagonistic. Insulin and glucagon are a pair of antagonistic hormones that help regulate the level of glucagon in the blood. Positive feedback loops actually tend to destabilize systems by increasing changes. A negative feedback loop acts to make a system more stable by buffering changes.

Define homeostasis, gene expression, transcription, translation, and cellular differentiation. Discuss the relative sizes of cells and organelles.

Homeostasis: This describes the ability and tendency of an organism, cell, or body to adjust to environmental changes to maintain equilibrium. Gene expression: This refers to the use of information in a gene, usually during the processes of transcription and translation, that result in a protein product. Transcription: This refers to the synthesis of RNA. Information is provided by DNA. Translation: This is the decoding of mRNA (messenger RNA) used in the fabrication of protein. It occurs after transcription. Cellular differentiation: This is the process by which a less specialized cell becomes a more specialized cell. Size: The size of the nucleus in a eukaryotic cell is about 6 micrometers. It occupies about 10 percent of the cell. A chloroplast is about 1 micrometers. Plant and animal cell sizes range from about 10-100 micrometers, while the

Provide an overview of glycolysis

In glycolysis, glucose is converted into pyruvate and energy stored in ATP bonds is released. Glycolysis can involve various pathways. Various intermediates are produced that are used in other processes, and the pyruvic acid produced by glycolysis can be further used for respiration by the Krebs cycle or in fermentation. Glycolysis occurs in both aerobic and anaerobic organisms. Oxidation of molecules produces reduced coenzymes, such as NADH. The coenzymes relocate the hydrogens to the electron transport chain. THe proton is transported through the cell membrane and the electron is transported down the chain by proteins. At the end of the chain, water is formed when the final acceptor releases two electrons that combine with oxygen. THe protons are pumped back into the cell or organelle by the ATP synthase enzyme, which uses energy produced to add a phosphate to ADP to form ATP. The proton motive force is produced by the protons being moved across the membrane.

List the primary events that occur during mitosis.

Interphase, Prophase, Metaphase, Anaphase, Telophase, Cytokinesis. Interphase: the cell prepares for division by replicating its genetic and cytoplasmic material. Interphase can be further divided into G1, S, and G2. Prophase: The chromatin thickens into chromosomes and the nuclear membrane begins to disintegrate. Pairs of centrioles move to opposite side of the cell and spindle fibers begin to form. The mitotic spindle, formed from cytoskeleton parts, moves chromosomes around within the cell. Metaphase: the spindle moves to the center ofthe cell and chromosome pairs align along the center of the spindle structue. Anaphase: The pairs of chromosomes, called sisters, begin to pull apart, and may bend. When they are separated, they are called daughter chromosomes. Grooves appear in the cell membrane. Telophase: The spindle disintegrates, the nuclear membranes reform, an the chromosomes revert to chromatin. In animal cells, the membrane is pinched. In plant cells, a new cell wall begins to form. Cytokinesis: This is the physical splitting of the cell (including the cytoplasm) into two cells. Cytokinesis begins during anaphase, as the cell begins to furrow, and is completed following telophase.

Define lethal allele, pleiotropy, epistasis, and karyotype. Discuss the interaction between heredity and environment.

Lethal allele: this is when a mutation in an essential gene results in the death of the organism. Cystic fibrosis and Tay-Sachs disease are examples of lethal recessive alleles. Pleiotropy: this refers to a gene that affects more than one trait. Epistasis: this refers to the situation in which two or more genes determine a single phenotype. Karyotype: this is a picture of genes based on a sample of blood or skin. The non-Mendelian concept of polygenetic inheritance takes into account environmental factors on phenotypes. For example, an individual inherits genes that help determine height, but a diet lacking in certain nutrients could limit that individual's ability to reach that height. Another example is the concept of genetic disposition, which is a propensity for a certain disease that is genetically inherited, but not necessarily manifested. For example, individuals with certain skin types are more likely to develop skin cancer. If they limit their exposure to solar radiation, however, this will not necessarily occur.

Elaborate on the functions of proteins in DNA replication

Many proteins are involved in the replication of DNA, and each has a specific function. Helicase is a protein that facilitates the unwinding of the double helix structure of DNA. Single strand binding (SSB) proteins attach themselves to each strand to prevent the DNA strands from joining back together. After DNA is unwound, there are leading and lagging strands. The leading strand is synthesized continuously and the lagging strand is synthesized in Okazaki fragments. Primase, and RNA polymerase (catalyzing enzyme), acts as a starting point for replication by forming short strands, or primers, of RNA. The DNA clamp, or sliding clamp, helps prevent DNA polymerase from coming apart from the strand. DNA polymerase helps form the DNA strand by linking nucleotides. As the process progresses, RNase H removes the primers. DNA ligase then links the existing shorter strands into a longer strand.

List the primary events that occur during meiosis

Meiosis has the same phases as mitosis, but they happen twice. In addition, different events occur during some phases of meiosis than mitosis. THe events that occur during the first phase of meiosis are interphase (I), prophase (I), metaphase (I), anaphase (I), telophase (I), and cytokinesis (I). During this first phase of meiosis, chromosomes cross over, genetic material is exchanged, and tetrads of four chromatids are formed. The nuclear membrane dissolves. Homologous pairs of chromatids are separated and travel to different poles. At this point, there has been one cell division, which consists of prophase (II), metaphase (II), anaphase (II), telophase (II), and cytokinesis (II). The result is four daughter cells with different sets of chromosomes. THe daughter cells are haploid, which means they contain half the genetic material of the parent cell. The second phase of meiosis is similar to the process of mitosis. Meiosis encourages genetic diversity.

Discuss Mendel's laws and Punnett squares

Mendel's law are the law of segregation (the first law) and the law of independent assortment. (the second law). The law of segregation states that there are two alleles and that half of the total number of alleles are contributed by each parent organism. The law of independent assortment states that traits are passed on randomly and are not influenced by other traits. The exception to this is linked traits. A Punnett square can illustrate how alleles combine from the contributing genes to form various phenotypes. One set of a parent's genes are put in columns, while genes from the other parent are placed in rows. The allele combinations are shown in each cell. When two different alleles are present in a pair, the dominant one is expressed. A Punnett square can be used to predict the outcome of crosses.

Define and discuss metabolism, macromolecules, metabolic pathways, and anabolic and catabolic reactions.

Metabolism is all of the chemical reactions that take place within a living organism that produce either energy or macromolecules. Macromolecules are large and complex, and play an important role in cell structure and function. Metabolic pathways refer to a series of reaction in which the product of one reaction is the substrate for the next. These pathways are dependent upon enzymes that act as a catalysts. An anabolic reaction is one that builds larger and more complex molecules (MACRO) from smaller ones. Catabolic reactions are the opposite. Larger molecules are broken down into smaller, simpler molecules. Catabolic reactions release energy, while anabolic ones require energy.

Explain what metamorphic rock is and how it is formed

Metamorphic rock is that which has been changed by great heat and pressure. This results in a variety of outcomes, including deformation, compaction, destruction of the characteristics of the original rock, bending, folding, and formation of new minerals because of chemical reactions, and changes in the size and shape of the mineral grain. For example, the igneous rock ferromagnesian can be changed into marble The texture of metamorphic rocks can be classified as foliated and unfoliated. Foliation, or layering, occurs when rock is compressed along one axis during recrystallization. This can be seen in schist and shale. Unfoliated rock does not include this banding. Rocks that are compressed equally from all sides or lack specific minerals will be unfoliated. An example is marble.

Explain how and why minerals are classified

Minerals are classified by chemical composition and internal crystalline structure. They are organized into classes. Native elements such as gold and silver are not classified in this manner. The eight classes are sulfides, oxides\hydroxides, halides, carbonates, sulfates, phosphates, and silicates. These classes are based on the dominant anion (negatively charged iron) or anionic group. Minerals are classified in this way for three main reasons. First, minerals with the same snion have unmistakable resemblances. Second, minerals with the same anion are often found in the same geologic environment. For example, calcite and dolomite, which belong to the same group, are often found together, Last, this method is similar to the naming convention used to identify inorganic compounds in chemistry. Minerals can be further separated into groups on the basis of internal structure.

Compare and contrast rocks and minerals

Minerals are naturally occurring, inorganic solids with a definite chemical composition and an orderly internal crystal structure. A polymorph is two minerals with the same chemical composition, but a different crystal structure. Rocks are aggregates of one or more minerals, and may also contain mineraloids (minerals lacking a crystalline structure) and organic remains. The three types of rocks are sedimentary, igneous, and metamorphic. Rocks are classified based on their formation and the minerals they contain. Minerals are classified by their chemical composition. Geology is the study of the planet Earth as it pertains to the composition, structure, and origin of its rocks. Petrology is the study of rocks, including their composition, texture, structure, occurrence, mode of formation, and history. Mineralogy is the study of minerals.

Discuss earthquakes as they relate to plate tectonics

Most earthquakes are caused by tectonic plate movement. They occur along fractures called faults or fault zones. Friction in the faults prevents smooth movement. Tension builds up over time, and the release of that tension results in earthquakes. Faults are grouped based on the type of slippage that occurs. The types of faults are dip-slip, strike-slip, and oblique-slip. A dip-slip fault involves vertical movement along the fault plane. In a normal dip-slip fault, the wall that is above the fault plane moves down. In a reverse dip-slip fault, the wall above the fault plane moves up. A strike-slip fault involves horizontal movement along the fault plane. Oblique-slip faults involve both vertical and horizontal movement. The Richter magnitude scale measure how much seismic energy was released by an earthquake.

Discuss the kingdom Fungi

Mycology is the study of fungi. The Fungi kingdom includes about 100,000 species. They are further delineated as mushrooms, yeasts, molds, rusts, mildews, stinkhorns, puffballs, and truffles. Fungi are characterized by cell walls that have chitin, a long chain polymer carbohydrate. Fungi are different from species in the Plant kingdom, which have cell walls consisting of cellulose. Fungi are thought to have evolved from a single ancestor. Although they are often thought of as a type of plant, they are more similar to animals than plants. Fungi are typically small and numerous, and have a diverse morphology among species. They can have bright red cups and be orange jellylike masses, and their shapes can resemble gold balls, bird nests with eggs, starfish, parasols, and male genitalia. Some members of the stinkhorn family emit odors similar to dog scat to attract flies that help transport spores that are involved in reproduction. Fungi of this family are also consumed by humans.

Define and describe the following nuclear parts of a eukaryotic cell: nucleus, chromosomes, chromatin, nucleolus, nuclear envelope, nuclear pores, and nucleoplasm.

Nucleus (plural form; nuclei): This is a small structure that contains the chromosomes and regulates the DNA of a cell. The nucleus is the defining structure of eukaryotic cells, and all eukaryotic cells have a nucleus. The nucleus is responsible for the passing on of genetic traits between generations. The nucleus contains a nuclear envelope, nucleoplasm, a nucleolus, nuclear pores, chromatin, and ribosomes. Chromosomes: These are highly condensed, threadlike rods of DNA. Short for deoxyribonucleic acid, DNA is the genetic material that stores information about the plant or animal. Chromatin: THis consists of the DNA and protein that make up chromosomes. Nucleolus (nucleole) This structure contained within the nucleus consists of protein. It is small, round, does not have a membrane, is involved in protein synthesis, and synthesizes and stores RNA. (ribonucleic acid). Nuclear envelope: This encloses the structures of the nucleus. It consists of inner and outer membranes made of lipids. Nuclear pores: These are involved in the exchange of material between the nucleus and the cytoplasm. Nucleoplasm: This is the liquid within the nucleus, and is similar to cytoplasm.

Explain scientific theories of the origin of life on Earth.

One theory of how life originated on Earth is that life developed from nonliving materials. The first stage of this transformation happens when abiotic (nonliving) synthesis took place, which is the formation of monomers like amino acids and nucleotides. Next, monomers joined together to create polymers such as proteins and nucleic acids. These polymers are then believed to have formed into protobionts. The last stage was the development of the process of heredity. Supports of this theory believe that RNA was the first genetic material. Another theory postulates that hereditary systems came about before the origination of nucleic acids. Another theory is that life, or the precursors for it, were transported to Earth from a meteorite or other object from space. There is no real evidence to support this theory.

Explain the classification of organisms that are part of the kingdom Protista.

Organisms in the Protista kingdom are classified according to their methods of locomotion, their methods or reproduction, and how they get their nutrients. Protists can move by the use of a flagellum, cilia, or pseudopodia. Flagellates have flagellum, which are long tails are whip-like structure that are rotated to help the protist move. Ciliates use cilia, which are smaller hair-like structures on the exterior of a cell that wiggle to help move the surrounding matter. Amoeboid use pseudopodia to move. Bacteria reproduce either sexually or asexually Binary fission is a form of asexual reproduction whereby bacteria divide in half to produce two new organisms that are clones of the parent. In sexual reproduction, genetic material is exchanged. When kingdom members are categorized according to how they obtain nutrients, the three types of protists are photosynthetic, consumers, and saprophytes. Photosynthetic protists convert sunlight into energy. Organisms that use photosynthesis are considered producers. Consumers, also known as heterotrophs, eat or consume other organisms. Saprophytes consume dead or decaying substances.

Outline the differences between plant and animal cells

Plant cells can be much larger than animal cells, ranging from 10 to 100 micrometers. Animal cells are 10-30 micrometers in size. Plant cells can have much larger vacuoles that occupy a large portion of the cell. They also have cell walls, which are thick barriers consisting of protein and sugars. Animal cells lack cell walls. Chloroplasts in plants that perform photosynthesis absorb sunlight and convert it into energy. Mitochondria produce energy from food in animal cells. Plant and animal cells are both eukaryotic, meaning they contain a nucleus. Both plant and animal cells duplicate genetic material, separate it, and then divide in half to reproduce. Plant cells build a cell plate between two new cells, while animal cells make a cleavage furrow and pinch in half. Microtubules are components of the cytoskeleton in both plant and animal cells. Microtubule organizing centers (MTOCs) make microtubules in plant cells, while centrioles make microtubules in animal cells.

Identify some major and specialized parts of the root system and the transportaion system in plants.

Plant roots include zones where cell differentiation, elongation and division, jand meristem formation occur. Primary meristems include protoderms, ground meristems, procambiums, and apical meristems. There is also a root cap. A tuber is an underground stem that is enlarged and used for food storage. A rhizome is an underground stem of sorts that sends out roots and shoots from its nodes (bulging or swelling points). Vascular tissues include xylem and phloem. Xylem can be scattered throughout a pith or formed into rings. Phloem allows for food transport down a plant. The food travels from where it was produced through photosynthesis to other structures, such as roots, that require the food. Phloem can be made up of bundles of sieve tubes. It is usually located outside of the xylem.

Discuss the major processes and systems of plants.

Plants are autotrophs, which means they make their own food. In a sense, they are self sufficient. Three major processes used by plants are photosynthesis, transpiration, and respiration. Photosynthesis involves using sunlight to make food for plants. Transpiration evaporates water out of plants. Respiration is the utilization of food that was produced during photosynthesis. Two major systems in plants ar the shoot and the root system. THe shoot system includes leaves, buds, and stems. It also includes the flowers and fruits in flowering plants. The shoot system is located above the ground. The root system is the component of the plant that is underground, and includes roots, tubers, and rhizomes. Meristems form plant cells by mitosis. Cells then differentiate into cell types to form the three types of plant tissues, which are dermal, ground, and vascular. Dermal refers to tissues that form the covering or outer layer of a plant. Ground tissue consists of parenchyma, collenchyma, and/or sclerenchyma cells.

Discuss population, population growth, carrying capacity, population curves, population dynamics, and biotic potential.

Population is a measure of how many individual exist in a specific area. It can be used to measure the size of human, plant, or animal groups. Population growth depends on many factors. Factors that can limit the number of individuals in a population include lack of resources such as food and water, space, habitat destruction, competition, disease and predators. Exponential growth refers to an unlimited rising growth rate. This kind of growth can be plotted on a chart in the shape of a J. Carrying capacity is the population size that can be sustained. The world's population is about 7.5 billion and growing. The human population has not yet reached its carrying capacity. Population dynamics refers to how a population changes over time and the factors that cause changes. An S-shaped curve shows that population growth has leveled off. Biotic potential refers to the maximum reproductive capacity of a population given ideal environmental conditions.

Discuss interspecific relationships. Define predation, parasitism, commensalism, and mutualism.

Predation, parasitism, commensalism, and mutualism are all types of species interactions that affect species populations. Intraspecific relationships are relationships among members of a species. Interspecific relationships are relationships between members of a different species. Predation: THis is a relationship in which one individual feeds on another (the prey), causing the prey to die. Commensalism: This refers to interspecific relationships in which one of the organisms benefits. Mutualism, competition, and parasitism are all types of commensalism. Mutualism: this is a relationship in which both organisms benefit from an interaction. Competition: this is a relationship in which both organisms are harmed. Parasitism: this is a relationship in which one organism benefits and the other is harmed. Biomass: in ecology, biomass refers to the mass of one or all of the species (species biomass) in an ecosystem or area.

Cell Cycle

Process by which a cell reproduces, this involves cell growth, duplication of genetic material, and cell division. The cell cycle can take 24 hrs in animal cells. Time varies between cell types. Neurons do not grow or divide. Cells can reproduce two ways; meiosis and mitosis. Mitosis replication, the "daughter cell" is an exact replica of the parent cell. In meiosis, the daughter cells have different genetic coding than the parent cell. Meiosis only happens in specialized reproductive cells called gametes.

Describe RNA and its three types

RNA acts as a helper to DNA and carries out a number of other functions. Types of RNA include ribosomal RNA (rRNA), transfer RNA (tRNA), and messenger RNA (mRNA). Viruses can use RNA to carry their genetic material to DNA. Ribosomal RNA is not believed to have changed much over time. For this reason, it can be used to study relationships in organisms. Messenger RNA carries a copy strand of DNA and transports it from the nucleus to the cytoplasm. Transcription is the process whereby DNA use RNA in transcription. DNA unwinds itself and serves as a template while RNA is being assembled. The DNA molecules are copied to RNA. Translation is the process whereby ribosomes use transcribed RNA to put together the needed protein. Transfer RNA is a molecule that helps in the translation process, and is found in the cytoplasm. Ribosomal RNA is in the ribosomes.

Differentiate between RNA and DNA

RNA and DNA differ in terms of structure and function. RNA has a different sugar than DNA. It has ribose rather than deoxyribose sugar. The RNA nitrogenous bases are adenine (A), guanine (G), cytosine (C), and uracil (U). Uracil is only found in RNA and thymine (T) is found only in DNA. RNA consists of a single strand and DNA has two strands. If straightened out, DNA has two side rails. RNA only has on "backbone", or strand of sugar and phosphate group components. RNA uses the fully hydroxylated sugar pentose, which includes an extra oxygen compared to deoxyribose, which is sugar used by DNA. RNA supports the functions carried out by DNA. It aids in gene expression, replication, and transportation.

Define and describe the following cell structures: ribosomes, Golgi complex, vacuoles, vesicle, cytoskeleton, and microtubules

Ribosomes are involved in synthesizing proteins from amino acids. They are numerous, making up about one quarter of the cell. Some cells contain thousands of ribosome. Some are mobile and some are embedded in the rough endoplasmic reticulum. Golgi complex (golgi apparatus) is involved in synthesizing materials such as proteins that are transported out of the cell. It is located near the nucleus and consists of layers of membranes. Vacuoles are sacs used for storage, digestion, and waste removal. There is one large vacuole in plant cells. Animal cells have small, some times numerous vacuoles. Vesicles are small organelle within a cell. It has a membrane and performs varying functions, including moving materials within a cell. Cytoskeleton consists of microtubules that help shape and support hecell. Microtubules are part of the cytoskeleton and help support the cell. They are made of protein.

List the scientific evidence that supports the theory of evolution.

Scientific evidence supporting the theory of evolution can be found in biogeography, comparative anatomy and embryology, the fossil record, and molecular evidence. Biogeography studies the geographical distribution of animals and plants. Evidence of evolution related to the area of biogeography includes species that are well suited for extreme environments. The fossil record shows that species lived only for a short time period before becoming extinct. The fossil record can also show the succession of plants and animals. Living fossils are existing species that have not changed much morphologically and are very similar to ancient examples in the fossil record. Examples include the horseshoe crab and ginko. Comparative embryology studies how species are similar in the embryonic stage, but become increasingly specialized and diverse as they age. Vestigial organs are those that still exist, but become nonfunctional. Examples include the hind limbs of whales and the wings of birds that can not longer fly, such as ostriches.

Explain what sedimentary rock is and how it is formed

Sedimentary rocks are formed by the process of lithification, which involves compaction, the expulsion of liquids from pores, and the cementation of the pre-existing rock. It is pressure and temperature that are responsible of this process. Sedimentary rocks are often formed in layers in the presence of water, and may contain organic remains, such as fossils. Sedimentary rocks are organized into three groups: detrital, biogenic, and chemical. Texture refers to the size, shape, and grains of sedimentary rock. Texture can be used to determine how a particular sedimentary rock was created. Composition refers to the types of minerals present in the rock. The origin of sedimentary rock refers to the type of water that was involved in its creation. Marine deposits, for example, likely involved ocean environments, while continental deposits likely involved dry land and lakes.

Differentiate between skeletal, smooth, and cardiac muscle in mammals.

Skeletal muscle is strong, quick and capable of voluntary contraction. Skeletal muscle fibers are striated and cylinder shaped. They have about 25 nuclei that are located to the side of the cell. Skeletal muscle consists of myofibrils that contain two types of filaments (myofilaments) made of proteins, The two types of filaments are actin and myosin. These filaments are aligned, giving the appearance of striation. During contraction, they slide against each other and become more overlapped. Smooth muscle is weak, slow, and usually contract involuntarily. Examples in humans can be found in the gastrointestinal tract, blood vessels, bladder, uterus, hair follicles, and parts of the eye. Smooth muscle fibers are not striated, but spindle shaped. They are somewhat long and a little wider in the center. Each cell contains one nucleus that is centrally located. Smooth muscle cells also contain myofibrils, but they are not aligned. Cardiac muscle is strong, quick and continuously contracts involuntarily. It is found in the myocardium of the heart.

Define the following prezygotic barriers to reproduction: spatial, geographical, habitat, temporal, behavioral, mechanical, and gametic isolation.

Spatial: this refers to species that are separated by a distance that prevents them from mating. Geographical: this is when species are physically separated by a barrier. A barrier can divide a population, which is known as vicariance. If a population crosses a barrier to create two species, it is known as dispersal. Habitat: this refers to species that live in different habitats in the same area. Temporal: this refers to the fact that species reach sexual maturity at different times. An example is plants that flower at different times of the year. Behavioral: this refers to the fact that mating rituals distinguish interaction between sexes. For example, many species of crickets are morphologically (structurally) the same, yet a female of one species will only respond to the mating rituals of males within her species. Mechanical: this refers to the physiological structural differences that prevent mating or the transfer of gametes. Gametic isolation: this refers to the fact that fertilization may not occur when gametes of different species are not compatible.

Discuss systems and structures in animals

Systems in animals have developed to perform various functions, including providing physical protection and obtaining food. Some animals have internal or external skeletons, shells, or skin that provide protection and support. Skin helps prevent water loss. Muscle systems enable movement. Brains and nervous systems help animals respond ot external stimuli by processing incoming and outgoing signals. The main systems in animals are skeletal, muscular, nervous, digestive, respiratory, reproductive, and circulatory. THe human stomach, for example, aids in the process of turning consumed food sources into energy. It has many tissue types; smooth muscle tissue, loose connective tissue, nervous tissue, blood, and columnar epithelial tissue. Many animals have a stomach or digestive chamber with two openings. These are known as metazoans.

Define the following social behaviors: territoriality, dominance, altruism, and threat display. Explain the principle of competitive exclusion.

Territoriality: this refers to members of a species protecting areas from other members of their species and from other species. Species members claim specific areas as their own. Dominance: this refers to the species in a community that is the most populous. Altruism: this is when a species or individual in a community exhibits behaviors that benefit another individual at a cost to itself. In biology, altruism does not have to be a conscious sacrifice. Threat display: this refers to behavior by an organism that is intended to intimidate or frighten away members of its own or another species. The principle of competitive exclusion (Gause's Law) states that if these are limited or insufficient resources and species are competing for them, these species will not be able to co-exist. The result is that one of the species will become extinct or be forced to undergo a behavioral or evolutionary change. Another way to say this is that "complete competitors cannot coexist".

List some facts about the major organ systems in general and the skeletal, muscular, and nervous systems in particular.

The 11 major organ systems are: skeletal, muscular, nervous, digestive, respiratory, circulatory, skin, excretory, immune, endocrine, and reproductive. Skeletal: this consists of the bones and joints. the skeletal system provides support for the body through its rigid structure, provides protection for internal organs, and works to make organisms motile. Growth hormone affects the rate of reproduction and the size of the body cells, and also helps amino acids move through membranes. Muscular: this includes the muscles. The muscular system allows the body to move and respond to its environment. Nervous: this includes the brain, spinal cord, and nerves. The nervous system is a signaling system for intrabody communications among systems, responses to stimuli, and interaction within an environment. Signals are electrochemical. Conscious thoughts and memories and sense interpretation occur in the nervous system. It also controls involuntary muscles and functions, such as breathing and the beating of the heart.

Describe the Earth's structure

The Earth is ellipsoid, not perfectly spherical. THis means the diameter is different through the poles and at the equator. Through the poles, the Earth is about 12,715 kim in diameter. This approximate center of the Earth is at a depth of 6,378 km. The Earth is divided into a crust, mantle, and core. The core consists of a solid inner portion. Moving outward, the molten outer core occupies the space from about a depth of 5,150 km to the depth of 2,890km. The mantle consists of a lower and upper layer. The lower layer includes the D' (D prime) and D" (D double-prime) layers. The solid portion of the upper mantle and crust together form the lithosphere, or rocky sphere. Below this, but still within the mantle, is the asthenosphere, or weak sphere. These layers are distinguishable because the lithosphere is relatively rigid, while the asthenosphere resembles a liquid.

Describe the Earth's chemical composition

The Earth's core consists of hot iron and forms of nickel. THe mantle consists of different materials, including iron, magnesium,, and calcium. The crust covers the mantle consists of a thin layer of much lighter rocks, and is further subdivided into continental and oceanic portions. The continental portion consists mainly of silicates, such as granite. The oceanic portion consists of heavier, volcanic rocks, such as basalt. The upper 10 miles of the lithosphere layer (the crust and part of the mantle) is made up of 95% igneous rock (or its metamorphic equivalent), 4% shale, 0.75% sandstone, and 0.25% limestone. THere are over 4,000 known minerals, but only about 20 make up some 95% of all rocks. There are, however, more than 3.000 individual kinds of minerals in the Earth's crust. Silicates are the largest group of minerals.

Discuss the subdivisions of the animal kingdom

The animal kingdom includes about one million species. Metazoans are multicellular animals. Food is ingested and enters a mesoderm-lined coelom (body cavity). Phylum porifera and coelenterate are exceptions. The taxonomy of animals involves grouping them into phyla according to body symmetry and plan, as well as the presence of or lack of segmentation. The more complex ad phyla that have coelom and a digestive system are further classified as protostomes or deuterostomes according to blastula development. In protostomes, the clastul's blastopore (opening) forms a mouth. In deuterostomes, the blastopore forms and anus. Taxonomy schemes vary, but there are about 36 phyla of animals. The corresponding term for plants are this level is division. The most notable phyla include chordata, mollusca, porifera, cnidaria, platyhelminthes, nematoda, annelida, arthropoda, and echinodermata, which account for about 96 percent of all animal species.

List some facts about the animal kingdom.

The animal kingdom is comprised of more than one million species in about 30 divisions (the plant kingdom uses the term phyla). There about 800,000 species of insects alone, representing half of all animals species. The characteristics that distinguish members of the animal kingdom from members of other kingdoms are that they are multicellular, are heterotrophic, reproduce sexually (there are some exceptions), have cells that do not contain cell walls or photosynthetic pigments, can move at some stage of life, and can rapidly respond to the environment as a result of specialized tissues like nerve and muscle. Heterotrophic refers to a method of getting energy by eating food that has energy releasing substances. Plants, on the other hand, are autotrophs, which mean they make their own energy. During reproduction, animals have diploid embryo in the blastula stage. This structure is unique to animals. The blastula resembles a fluid-filled ball.

Discuss pollination in flowering plants.

The anthers of the stamens (male parts) have microsporangia that form into a pollen grain, which consists of a small germ cell within a larger cell. the pollen grain is released and lands on a stigma (female) portion of the pistil. It grows a pollen tube the length of the style and ends up at the ovule. The pollen grain releases the sperm and fertilization occurs. In double fertilization, one of the sperm joins with the egg to become a diploid zygote. The other sperm becomes the endosperm nucleus. Seeds are formed. One cotyledon (monocot) or two cotyledons (dicot) also form to store food and surround the embryo. Correspondingly, monocots produce one seed leaf, while dicots produce two. The seed matures and becomes dormant, and fruits typically form.

Explain Cell Theory

The basic tenets of cell-theory are that all living things are made up of cells and that cells are the basic units of life. Cell theory has evolved over time and is subject to interpretation. The development of cell theory is attributed to Matthias Schleiden and Theodor Schwann, who developed the theory in the early 1800s. Early cell theory was comprised of four statements: all organisms (living things) are made up of cells; new cells are formed from pre-existing cells; all cells are similar; and cells are the most basic units of life. Other concepts related to classic and modern cell theory include statements such as: cells provide the basic units of functionality and structure in living things; cells are both distinct stand-alone units and basic building blocks; energy flow occurs within cells; cells contain genetic information in the form of DNA; and all cells consist of mostly the same chemicals.

List the major glands of the endocrine system and describe how the system works. Identify the hormones of the endocrine system and how they influence the adrenal glands, islets of Langerhans, and the parathyroid.

The endocrine system includes the pituitary gland, pineal gland, hypothalamus, thyroid gland, parathyroids, thymus, adrenals, pancreas, ovaries, and testes. It controls systems and processes by secreting hormones into the blood system. Exocrine glands are those that secrete fluid into ducts. Endocrine glands secrete hormones directly into the bloodstream without the use of ducts. Prostaglandin (tissue hormones) diffuses only a short distance from the tissue that created it, and influences nearby cells only. Adrenal glands are located above each kidney. The cortex secrets some sex hormones, as well as kidney. The cortex secretes some sex hormones, as well as mineralocorticoids and glucocorticoids involved in immune suppression. The medulla secretes epinephrine and norepinephrine. Both elevate blood sugar, increase blood pressure, and accelerate heart rate. Epinephrine also stimulates heart muscle. The islets of Langerhans are clumped within the pancreas and secrete glucagon and insulin, thereby regulating blood sugar levels. The four parathyroid glands at the rear of the thyroid secrete parathyroid hormone.

Discuss the five kingdom classification system.

The groupings in the five kingdom classification system are kingdom, phylum/division, class, order, family, genus, and species. A memory aid is King Phillip Came Over For Good Soup. The fine kingdoms are Monera, Protista, Fungi, Plantae, and Animalia. The kingdom is the top level of classification in this system. Below that are the following groupings; phylum, class, order, family, genus, and species. The Monera kingdom includes about 10,000 known species of prokaryotes, such as bacteria and cyanobacteria. Members of this kingdom can be unicellular organisms or colonies. The next four kingdoms consist of eukaryotes. The Protista kingdom includes about 250,00 species of unicellular protozoans and unicellular and multicellular algae. The Fungi kingdom includes about 100,000 species. A recently introduced system of classification includes a three domain grouping above kingdom. The domain groupings are Archaea, Bacteria (which both consist of prokaryotes), and Eukarya, which include eukaryotes. According to the five kingdom classification system, humans are: kingdom Animalia, phylum CHordata, subphylum Vertebrata, class Mammalia, order Primate, family Hominidae, genus Homo, and species Sapiens.

Discuss the Krebs cycle, in particular its steps and products.

The krebs cycle is also called the citric acid cycle or the tricarboxylic acid cycle (TCA) It is a catabolic pathway in which the bonds of glucose and occasionally fats or lipids are broken down and reformed into ATP. It is a respiration process that uses oxygen and produces carbon dioxide, water, and ATP. Cells require energy from ATP to synthesize proteins from amino acids and replicate DNA. The cycle is acetyl CoA, citric acid, isocitric acid, ketoglutaric acid (products are amino acids and CO2), succinyl CoA, succinic acid, fumaric acid, malic acid, and oxaloacetic acid. One of the products of the Krebs cycle is NADH, which is then used in the electron chain transport system to manufacture ATP. From glycolysis, pyruvate is oxidized in a step linking to the Krebs cycle. After the Krebs cycle, NADH and succinate are oxidized in the electron transport chain.

Compare eukaryotic and prokaryotic cells

The main difference between eukaryotic and prokaryotic cells is that eukaryotic cells have a nucleus and prokaryotic cells do not. Eukaryotic cells are considered more complex, while prokaryotic cells are smaller and simpler. Eukaryotic cells have membrane-bound organelles that perform various functions and contribute to the complexity of these types of cells. Prokaryotic cells do not contain membrane-bound organelles. In prokaryotic cells, the genetic material (DNA) is not contained within a membrane-bound nucleus. Instead, it aggregates in the cytoplasm in a nucleoid. The eukaryotic cells, DNA is mostly contained in chromosomes in the nucleus, although there is some DNA in mitochondria and chloroplasts. Prokaryotic cells usually divide by binary fission and are haploid. Eukaryotic cells divide by mitosis and are diploid. Prokaryotic structures include plasmids, ribosomes, cytoplasm, a cytoskeleton, granules of nutritional substances, a plasma membrane, flagella, and a few others. They are single-celled organisms. Bacteria are prokaryotic cells.

Explain sexual reproduction, seed formation, and germination in flowering plants.

There are at least 230,000 species of flowering plants. They represent about 90% of all plants. Angiosperms have a sexual reproduction phase that includes flowering. When growing plants, one may think they develop in the following order: seeds, growth, flowers, and fruit. The reproductive cycle has the following order: flowers, fruit, and seeds. In other words, seeds are the products of successful reproduction. THe colors and scents of flowers seve to attract pollinators. Flowers and other plants can also be pollinated by wind. When a pollen grain meets the ovule and is successfully fertilized, the ovule develops into a seed. A seed consists of three parts: the embryo, the endosperm, and a seed coat. The embryo is a small plant that has started to develop, but this development is paused. Germination is when the embryo starts to grow again. The endosperm consists of proteins, carbohydrates, or fats. It typically serves as a food source for the embryo. The seed coat provides protection from disease, insects, and water.

Discuss blood typing in terms of genetics

There are four possible blood types A, B, AB, and O. These types are produced by combinations of the three alleles. AA and AO lead to type A blood. BB and BO lead to type B blood. AB leads to type AB blood because the alleles are co-dominant. AB has both A protein and antigens and B proteins and antigens. THe O allele is recessive. OO leads to blood type O, which lacks proteins and blood-surface antigens. Blood donors with an O blood type are known as universal donors because they do not have the type of antigens that can trigger immune system response. Blood donors with type AB blood are known as universal recipients because they do not have the antibodies that will attack A and B antigen molecules. If parents have AB and O blood offspring have a 50% chance of having type A blood and a 0% chance of having type O blood.

Compare mechanical and chemical weathering

There are two basic types of weathering: mechanical and chemical. Weathering is a very prominent process on the Earth's surface. Materials weather at different rates, which are known as differential weathering. .Mechanical and chemical weathering is interdependent. For example, chemical weathering can loosen the bonds between molecules and allow mechanical weathering to take place. Mechanical weathering can expose the surfaces of land masses and allow chemical weathering to take place. Impact, abrasion, frost wedging, root wedging, salt wedging and uploading are types of mechanical weathering. Types of chemical weathering are dissolution, hydration, hydrolysis, oxidation, biological, and carbonation. The primary type of chemical weathering is caused by water dissolving a mineral. The more acidic water is, the more effective it is at weathering. Carbonic and sulfuric acids can enter rain when they are present in the atmosphere. This lowers the pH value of rain, making it more acidic. Normal rain water has a pH value of 5.5. Acid rain has a pH value of 4 or less.

Explain three types of evolution and discuss the mechanisms of evolution. Define species, speciation, and the biological species concept.

Three types of evolution are divergent, convergent, and parallel. Divergent evolution refers to two species that become different over time. This can be caused by one of the species adapting to a different environment. Convergent evolution refers to two species that start out fairly different, but evolve to share many similar traits. Parallel evolution refers to species that are not similar and do not become more or less similar over time. Mechanisms of evolution include descent (the passing of genetic information), mutation, migration, natural selection, and genetic variation and drift. The biological definition of species refers to a group of individuals that can mate and reproduce. Speciation refers to the evolution of a new biological species. The biological species concept BSC basically states that a species is a community of individuals that can reproduce and have a niche in nature.

Define translocation and explain how it occurs in individuals with Down syndrome.

Translocation is a genetic mutation in which one piece of a chromosome is transferred to another chromosome. Burkitt's lymphoma, chronic myelogenous leukemia, and Down syndrome are all examples. Trisomy 21, or Down syndrome, occurs when a copy of chromosome 21 attaches to chromosome 12. Most Down syndrome cases are caused by a pair of chromosomes (the 21st) that does not split during meiosis. Both divided cells will have an abnormal number of chromosomes. One will have 22 and the other will have 24. When this egg gets fertilized, it will have three copies of chromosome 21 instead of two. Down syndrome can also be caused by translocation between the 14th and 21st chromosomes. In these instances, genetic material is swapped. There are 200 to 250 genes on the 21st chromosome. THe overexpression of gene results in the following Down syndrome traits; premature aging, decreased immune system function, heart defects, skeletal abnormalities, disruption of DNA synthesis and repair, intellectual disabilities, and cataracts.

Explain tropism, geotropic, plagiotropic, phototropism, and thigmotropism. Discuss plant hormones.

Tropism refers to the fact that plants grow in response to specific stimuli. Seeds are geotropic (or gravitropic) meaning they grow as a response to gravity. Roots are positively geotropic and grow towards gravity. A seed planted upside down will still grow roots and stems in the right direction. Plagiotropic refers to the fact that secondary branches and roots grow at right angles to gravity. Phototropism refers to the fact that a plant bends or grows toward a light source. Thigmotropism refers to how plants respond to contact. Plant hormones are organic compounds that usually influence changes in plants. They can cause fruit to ripen or instigate plant growth. Five major groups of hormones are auxins, gibberellins, ethylenes, cytokinins, and abscisic acids. Auxins occur naturally and can be synthesized. They affect plant cell elongation, apical dominance, and rooting. Gibberellins affect plant height. Ethylenes help fruit ripen. Cytokinins are involved in cell division. Abscisic acids inhibit other hormones .

List some facts about and characteristics of viruses

Viruses are microorganisms that replicate in the cells of other organisms, including plants, animals, bacteria, and other microorganisms. All viruses have a head. Some also have a tail consisting of protein. THe tail is used to attach to a host cell and enter it. This is one way in which viruses introduce their genetic material to the host. The head of a virus, also called a protein capsid, contains genetic material in the form of DNA, RNA, or enzymes. The adenovirus and the herpes virus are both DNA viruses. The HIV retrovirus, influenza, and the rotavirus are RNA viruses. the number of virus types is thought to be in the millions. Virology is a branch of microbiology that is devoted to the study of viruses. Viruses can be transmitted to other organisms in a number of ways, such as by insects, by air and through direct contact.

Discuss volcanic activities and plate tectonics

Volcanoes can occur along any type of tectonic plate boundary. At a divergent boundary, as plates move apart, magma rises to the surface, cools, and forms a ridge. An example of this is the mid-Atlantic ridge. Convergent boundaries, where one plate slides under another, are often areas with a lot of volcanic activity. The subduction process creates magma. When it rises to the surface, volcanoes can be created. Volcanoes can also be created in the middle of a plate over hot spots. Hot spots are locations where narrow plumes of magma rise through the mantle in a fixed place over a long period of time. The Hawaiian Islands and Midway are examples. The plate shifts and the island moves. Magma continues to rise through the mantle, however, which produces another island. Volcanoes can be active, dormant, or extinct. Active volcanoes are those that are erupting or about to erupt. Dormant volcanoes are those that might erupt in the future and still have internal volcanic activity. Extinct volcanoes are those that will not erupt.