MEGA/MOCA exam science flash cards elementary education multi-content

define atom, nucleus, electrons, and protons

-Atom- one of the most basic units of matter. An atom consists of a central nucleus surrounded by electrons. -Nucleus- central to atom, consists of protons and neutrons. It is positively charged, dense, and heavier than the surrounding electrons. The plural form of nucleus is nuclei. -Electrons- atomic particles that are negatively charged and orbit the nucleus of an atom -Protons- make up the nucleus of an atom along with neutrons. The number of protons in the nucleus determines the atomic number of an element. Carbon atoms, for example, have six protons. The atomic number of carbon is six. The number of protons minus the number of electrons indicates the charge of an atom.

define atomic number, neutrons, nucleon, and element

-Atomic number- the number of protons in the nucleus of an atom. A unique identifier for atoms. It can be represented as Z. Atoms with a neutral charge have an atomic number that is equal to the number of electrons. -Neutrons- the uncharged atomic particles contained within the nucleus. The number of neutrons in a nucleus can be represented as "N." -Nucleon- refers collectively to neutrons and protons -Element- matter with one particular type of atom. It can be identified by its atomic number. There are approximately 117 elements currently known, 94 of which occur naturally on Earth. Elements from the periodic table include hydrogen, carbon, iron, helium, mercury, and oxygen.

list the characteristics of the various orders of reptiles

-Crocodilia- This is a group of reptiles that can grow quite large, and includes alligators and crocodiles. Normally found near the water in warmer climates, Crocodilia might be more closely related to birds than other reptiles. -Squamata- This is the order of reptiles that includes snakes and lizards. Snakes are special because they have no legs and no ears. They feel vibrations, smell with their tongues, have specialized scales, and can unhinge their jaws to swallow prey that is larger than they are. Like snakes, lizards have scales, but they differ in that they have legs, can dig, can climb trees, and can grab things. -Chelonia- This is the order of reptiles that includes turtles and tortoises. It is a special group because its members have shells. Different varieties live in forests, water, and deserts, or anywhere the climate is warm enough. They also live a long time, even hundreds of years. Turtles are typically found near water and tortoises on land, even dry areas.

list some examples of energy transformations

-Electrical to mechanical: Ceiling fan -Chemical to heat: Internal combustion engine, transforms the chemical energy (a type of potential energy) of gas and oxygen into heat. This heat is transformed into propulsive energy, which is kinetic. Lighting a match and burning coal are also examples of chemical to heat energy transformations. -Chemical to light: Phosphorescence and luminescence (which allow objects to glow in the dark) occur because energy is absorbed by a substance (charged) and light is re-emitted comparatively slowly. This process is different from the one involved with glow sticks. They glow due to chemiluminescence, in which an excited state is created by a chemical reaction and transferred to another molecule. -Heat to electricity: Thermoelectric, geothermal, and ocean thermal. -Nuclear to heat: Examples include nuclear reactors and power plants. -Mechanical to sound: Playing a violin or almost any instrument. -Sound to electric: Microphone. -Light to electric: Solar panels. -Electric to light: Light bulbs.

define elements, compounds, solutions, and mixtures

-Elements- substances that consist of only one type of atom. -Compounds- substances containing two or more elements. Compounds are formed by chemical reactions and frequently have different properties than the original elements. Compounds are decomposed by a chemical reaction rather than separated by a physical one. -Solutions- homogeneous mixtures composed of two or more substances that have become one. -Mixtures- contain two or more substances that are combined but have not reacted chemically with each other. Mixtures can be separated using physical methods, while compounds cannot.

compare and contrast autotrophs, producers, herbivores, carnivores, omnivores, and decomposers

-Energy flows in one direction: from the sun, through photosynthetic organisms such as green plants (producers) and algae (autotrophs), and then to herbivores, carnivores, and decomposers. -Autotrophs are organisms capable of producing their own food. The organic molecules they produce are food for all other organisms (heterotrophs). -Producers are green plants that manufacture food by photosynthesis. -Herbivores are animals that eat only plants (deer, rabbits, etc). Since they are the first animals to receive the energy captured by producers, herbivores are called primary consumers. -Carnivores, or secondary consumers, are animals that eat the bodies of other animals for food. Predators (wolves, lions, etc) kill other animals, while scavengers consume animals that are already dead from predation or natural causes (buzzards). -Omnivores are animals that eat both plants and other animals (humans), Decomposers include saprophytic fungi and bacteria that break down the complex structures of the bodies of living things into simpler forms that can be used by other living things. This recycling process releases energy from organic molecules.

list the characteristics of arthropods

-Exoskeleton (outside instead of inside) -Molting. As the arthropod grows, it must shed its shell and grow a new one -Several legs, which are jointed -Advanced nervous systems that allow for hunting, moving around, finding a mate, and learning new behaviors for adaptation -Development through metamorphosis. As arthropods develop, they change body shape. There are two types of metamorphosis (complete- the entire body changes, as in the case of butterflies; gradual- the arthropod starts out small with no wings and then molts and grows wings, as in the case of grasshoppers) Arthropods include spiders, crustaceans, and the enormous insect species (26 orders) called uniramians. Ranging from fleas to mosquitoes, beetles, dragonflies, aphids, bees, flies, and many more, uniramians have exoskeletons made of chitin, compound eyes, complex digestive systems, and usually six legs. This group is extremely diverse. Some can fly, some have toxins or antennae, and some can make wax, silk, or honey.

define heat, energy, work, and thermal energy

-Heat: the transfer of energy from a body or system as a result of thermal contact. Heat consists of random motion and the vibration of atoms, molecules, and ions. The higher the temperature is, the greater the atomic or molecular motion will be. -Energy: the capacity to do work. -Work: the quantity of energy transferred by one system to another due to changes in a system that is the result of external forces, or macroscopic variables. Another way to put this is that work is the amount of energy that must be transferred to overcome a force. Lifting an object in the air is an example of work. The opposing force that must be overcome is gravity. Work is measured in joules (J). The rate at which work is performed is known as power. -Thermal energy: the energy present in a system due to temperature.

define mass, weight, volume, density, and specific gravity

-Mass: a measure of the amount of substance in an object. -Weight: a measure of the gravitational pull of Earth on an object. -Volume- a measure of the amount of space something occupies. There are many formulas to determine volume. For example, the volume of a cube is the length of one side cubed (a³) and the volume of a rectangular prism is length times width times height (l x w x h). The volume of an irregular shape can be determined by how much water it displaces. -Density: a measure of the amount of mass per unit volume. The formula to find density is mass divided by volume (D = m/V). It is expressed in terms of mass per cubic unit, such as grams per cubic centimeter (g/cm³). -Specific gravity: a measure of the ratio of a substance's density compared to the density of water.

list the five kingdoms of life forms and give a brief description of each

-Moneran Kingdom- This group contains the simplest known organisms (prokaryotes). Members have only one chromosome, reproduce asexually, may have flagella, and are very simple in form. Members are either bacteria or blue-green algae. -Protist Kingdom- This group contains the simplest eukaryotes. They have a true nucleus surrounded by a membrane that separates it from the cytoplasm. Most are one-celled and have no complex tissues like plants. Members include protozoa and algae. -Fungi Kingdom- Members have no chlorophyll, so they don't make their own food like plants. They reproduce using spores. Fungi are made up of filaments called hyphae that, in larger fungi, can interlace to form a tissue called mycelium. Fungi include mushrooms and microscopic organisms that may be parasitic. -Plant Kingdom- This group consists of all multi-celled organisms that have chlorophyll and make their own food. Plants have differentiated tissues and reproduce either sexually or asexually. -Animal Kingdom- This group consists of all multi-celled organisms that have no chlorophyll and have to feed on existing organic material. Animals have the most complex tissues and can move about.

list and briefly describe the life processes that all living things have in common

-Nutrition- process of obtaining, ingesting, and digesting foods; excreting unused or excess substances; and extracting energy from the foods to maintain structure -Transport (circulation)- the process of circulating essential materials such as nutrients, cells, hormones, and gases (oxygen and hydrogen) to the places they are needed by moving the through veins, arteries, and capillaries. Needed materials do not travel alone, but are piggybacked on transporting molecules. -Respiration- the process of breathing, which is exchanging gases between the interior and exterior using gills, trachea (insects), or lungs. -Regulation- the process of coordinating life activities through the nervous and endocrine systems. -Reproduction and growth- the process of producing more of one's own kind and growing them from birth to adulthood. The more highly evolved an animal is, the longer its growth time is. -Locomotion (in animals)- the process of moving from place to place in the environment by using legs, flight, or body motions.

define the following subfields of biology: zoology, botany, biophysics, biochemistry, cytology, histology, organology, physiology, genetics, ethology, and ecology

-Zoology- study of animals -Botany- study of plants -Biophysics- application of the laws of physics to the processes of organisms and the application of the facts about living things to human processes and inventions -Biochemistry- study of the chemistry of living organisms, including diseases and the pharmaceutical drugs used to cure them -Cytology- study of cells -Histology- study of tissues of plants and animals -Organology- study of tissues organized into organs -Physiology- study of the way organisms function, including metabolism, the exchange of matter and energy in nutrition, the senses, reproduction and development, and the work of the nervous system and brain -Genetics- study of heredity as it relates to the transmission of genes -Ethology- study of animal behavior -Ecology- study of the relationship of living organisms to their environments

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 (pairs of north and south) attract. The magnetic field is a set of invisible lines representing the paths of attraction and repulsion. Magnetism can occur naturally, 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 paperclips. Dropping the nail 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 a 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.

briefly 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 (1 nm to 500 nm) particles is called a 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 has solids dispersed through it, such as milk or gelatin. An aerosol spray is a colloidal 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 foam is a liquid that has gas dispersed through it.

describe mountains and define orogeny, folded mountains, fault-block mountains, and dome mountains

A mountain is a portion of the earth that has been raised above its surroundings by volcanic action or tectonic plate movement. Mountains are made up of igneous, metamorphic, and sedimentary rocks, and most lie along active plate boundaries. There are two major mountain systems. The Circum-Pacific encircles the entire Pacific Ocean, from New Guinea up across Japan and the Aleutians and down to southern South America. The Alpine-Himalaya stretches from northern Africa across the Alps and to the Himalayas and Indonesia. Orogeny is the term for the process of natural mountain formation. Therefore, physical mountains are orogens. Folded mountains are created through the folding of rock layers when two crustal plates come together. The Alps and Himalayas are folded mountains. The latter was formed by the collision of India with Asia. Fault-block mountains are created from the tension forces of plate movements. These produce faults that vertically displace one section to form a mountain. Dome mountains are created from magma pushing up through the earth's crust.

discuss solutions

A solution is a homogeneous mixture. A mixture is two or more different substances that are mixed together, but not combined chemically. Homogeneous 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 solute is the sugar and the solvent is the water. The intermolecular attraction between the solute and the solvent 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 that salt (NaCl) dissolves in water to create a solution. The Na⁺ and the Cl⁻ ions in salt interact with the molecules of water and vice versa to overcome the individual molecular forces of the solute and the solvent.

compare and contrast Earth's sun to other stars

A star begins as a cloud of hydrogen and some heavier elements drawn together by their own mass. This matter then begins to rotate. The core heats up to several mil degrees Fahrenheit, which causes the hydrogen atoms to lose their shells and their nuclei to fuse. This releases enormous amounts of energy. The star then becomes stable, a stage called the main sequence. This is the stage our sun is in, and it will remain in this stage until its supply of hydrogen fuel runs out. Stars are not always alone like our sun, and may exist in pairs or groups. The hottest stars shine blue-white; medium-hot stars like our sun glow yellow; and cooler stars appear orange. The earth's sun is an average star in terms of mass, light production, and size. All stars, including our sun, have a core where fusion happens; a photosphere (surface) that produces sunspots (cool, dark areas); a red chromosphere that emits solar (bright) flares and shooting gases; and a corona, the transparent area only seen during an eclipse.

explain the difference between abiotic and biotic factors

Abiotic factors are the physical and chemical factors in the environment that are nonliving, but upon which the growth and survival of living organisms depends. These factors can determine the types of plants and animals that establish themselves and thrive in a particular area. Abiotic factors include: -Light intensity available for photosynthesis -temperature range -available moisture -type of rock substratum -types of minerals -types of atmospheric gases -relative acidity (pH) of the system Biotic factors are the living components of the environment that affect, directly or indirectly, the ecology of an area, possibly limiting the type and number of resident species. The relationships of predator/prey, producer/consumer, and parasite/host can define a community. Biotic factors include: -population levels of each species -food requirements of each species -interactions between species -wastes produced

discuss the structure of atoms

All matter consists of atoms. Atoms consist of a nucleus and electrons. The nucleus consists of protons and neutrons. The properties of these are measurable; they have mass and an electrical charge. The nucleus is positively charged due to the presence of protons. Electrons are negatively charged and orbit the nucleus. The nucleus has considerably more mass than the surrounding electrons. Atoms can bond together to make molecules. Atoms that have an equal number of protons and electrons are electrically neutral. If the number of protons and electrons in an atom is not equal, the atom has a positive or negative charge and is an ion.

List some of the subjects that can be covered in the personal health portion of science class

Among the personal and social perspectives of science are the issues of personal and public health care. In this area, students learn such things as: -The importance of regular exercise to the maintenance and improvement of health -The need for risk assessment and educated decisions to prevent injuries and illnesses because of the potential for accidents and the existence of hazards -The risk of illness and the social and psychological factors associated with the use of tobacco products -The dangers of abusing alcohol and other drug substances, including addiction and damage to body functions -The energy and nutrition values of various foods, their role in growth and development, and the requirements of the body according to variable factors -The complexities of human sexuality and the dangers of STDS -The relationship between environmental and human health, and the need to monitor soil, water, and air standards

describe the two types of aquifers

An aquifer is an underground water reservoir formed from groundwater that has infiltrated from the surface by passing through the soil and permeable rock layers (the zone of aeration) to a zone of saturation where the rocks are impermeable. There are two types of aquifers. In one the water is under pressure (confined) as the supply builds up between layers of impermeable rocks and has to move back towards the surface, resulting in a spring or artesian well. The second type of aquifer has room to expand and contract (unconfined) and the water has to be pumped out. The highest level of the aquifer is called the water table. If water is pumped out of the aquifer such that the water table dips in a specific area, that area is called a cone of depression.

define an ecological system and a biome and give examples of each

An ecological system, or ecosystem, is the community of all the living organisms in a specific area interacting with non-living factors such as temperature, sunlight, atmospheric pressure, weather patterns, wind, types of nutrients, etc. An ecosystem's development depends on the energy that passes in and out of it. The boundaries of an ecosystem depend on the use of the term, whether it refers to an ecosystem under a rock or in a valley, pond, or ocean. A biome is a general ecosystem type defined by the plants and animals that live there and the local climate patterns. Examples include tropical rainforests or savannas, deserts, grasslands, deciduous forests, tundra, woodlands, and ice caps. There can be more that one type of biome within a larger climate zone. The transition area between two biomes is an ecotone, which may have characteristics of both biomes.

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 or destroyed. If an equation is unbalanced, the numbers of atoms indicated by the stoichiometric coefficients on each side of the arrow won't 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, aren't possible. Equations can be balanced by multiplying the coefficients by a constant that produces the smallest possible whole number coefficient. H₂ + O₂ → 2H₂O, which indicates that it takes two moles of hydrogen and one of oxygen to produce two moles of water.

describe the characteristics of angiosperms

Angiosperms are plants that have flowers. This is advantageous because the plant's seeds and pollen can be spread not only by gravity and wind, but also by insects and pollinate the plant and distribute seeds. Some flowering plants also produce fruit. Then an animal eats the fruit, the plant seeds within get spread far and wide through the animal's excrement. There are two types of angiosperm seeds: monocotyledons (monocots) and dicotyledons (dicots). A cotyledon is the seed leaf or food package for the developing plant. Monocots are the simple flowering plants such as grasses, corn, palm trees, and lilies. They always have three petals on their flowers, and their leaves are longs strands (like a palm frond). A dicot has seeds with two cotyledons, or two seed leaves of food. Most everyday flowers are dicots with four or five petals and extremely complex leaves with veins. Examples include roses, sunflowers, cacti, and cherry trees.

identify the most abundant elements in the universe and on Earth

Aside from dark energy and dark matter, which are thought to account for all but four percent of the universe, the two most abundant elements in the universe are hydrogen (H) and helium (He). After hydrogen and helium, the most abundant elements are oxygen, neon, nitrogen, carbon, silicon, and magnesium. The most abundant isotopes in the solar system are hydrogen-1 and helium-4. Measurements of the masses of elements in the Earth's crust indicate that oxygen (O), silicon (Si), and aluminum (Al) are the most abundant chemical element in stars in their main sequences, but is relatively rare on planet Earth.

explain the relationship between conservation of matter and atomic theory

Atomic theory is concerned with the characteristics and properties of atoms that make up matter. It deals with the matter on a microscopic level as opposed to a macroscopic level. Atomic theory, for instance, discusses the kinetic motion of atoms in order to explain the properties of macroscopic quantities of matter. John Dalton (1766-1844) is credited with making many contributions to the field of atomic theory that are considered valid today. This includes the notion that all matter consists of atoms and that atoms are indestructible. In other words, atoms can be neither created nor destroyed. This is also the theory behind conservation of matter, which explains why chemical reactions do not result in any detectable gains or losses in matter. This holds true for chemical reactions and smaller scale processes. When dealing with large amounts of energy, however, atoms can be destroyed by nuclear reactions. This can happen in particle colliders or atom smashers.

discuss models of atoms

Atoms are extremely small. A hydrogen atom is about 5 x 10⁻⁸ mm in diameter. According to some estimates, five tril hydrogen atoms could fit on the head of a pin. Atomic radius refers to the average distance between the nucleus and the outermost electron. Models of atoms that include the proton, nucleus, and electrons typically show the electrons very close to the nucleus and revolving around it, similar to the Earth orbiting the sun. However, another model relates the Earth as the nucleus and its atmosphere as electrons, which is the basis of the term "electron cloud." Another description is that electrons swarm around the nucleus. It should be noted that these atomic models are not to scale. A more accurate representation would be a nucleus with a diameter of about 2 cm in a stadium. The electrons would be in the bleachers. This model is similar to the not-to-scale solar system model.

explain how atoms interact to form compounds

Atoms interact by transferring or sharing the electrons furthest from the nucleus. Known as the outer or valence electrons, they are responsible for the chemical properties of an element. Bonds between atoms are created when electrons are paired up by being transferred or shared. If electrons are transferred from one atom to another, the bond is ionic. If electrons are shared, the bond is covalent. Atoms of the same element may bond together to form molecules or crystalline solids. When two or more different types of atoms bind together chemically, a compound is made. The physical properties of compounds reflect the nature of the interactions among their molecules. These interactions are determined by the structure of the molecule, including the atoms they consist of and the distances and angles between them.

describe lipids, proteins, and nucleic acid

Besides hydrocarbons and carbohydrates, there are three other types of carbon molecules that are essential to life: lipids, proteins, and nucleic acids. Lipids are compounds that are insoluble or only partially soluble in water. There are three main types: fats, which act as an energy reserve for organisms; phospholipids, which are one of the essential components of cell membranes; and steroids such as cholesterol and estrogen, which are very important to metabolism. Proteins are complex substances that make up almost half the dry weight of animal bodies. These molecules contain hydrogen, carbon, oxygen, and other elements, chiefly nitrogen and sulfur. Proteins make up muscle fibers and, as enzymes, act as catalysts. Nucleic acids are large molecules (polymers) composed of a large number of simpler molecules (nucleotides). Each one has a sugar containing five carbons (pentose), a phosphorous compound (phosphate group), and a nitrogen compound (nitrogenated base). Nucleic acids facilitate perpetuation of the species because they carry genetic information as DNA and RNA.

define the euphotic zone, the bathyal zone, and the abyssal zone of the oceans

Beyond the subtidal zone, the ocean floor drops away to the deep ocean biome, which has three layers: The euphotic zone is the surface area of deep ocean water where there is a lot of sunshine and oxygen and therefore many small photosynthetic organisms. However, there are few nutrients because they fall to the bottom. The bathyal zone is the area further done that has dim light and no little organisms. It does, however, have some dish that go to feed on the organisms of the surface. The abyssal zone is the bottom of the ocean where it is pitch black. There are no producers and little oxygen. This zone is very cold and has high pressure. There are predator fish and living organisms that feed on whatever falls from the surface.

describe the biosphere

Biosphere is the term used by physical geographers to describe the living world of trees, bugs, and animals. It refers to any place where life exists on earth, and is the intersection of the hydrosphere, the atmosphere, the land, and the energy that comes from space. They biosphere includes the upper areas of the atmosphere where birds and insects can travel, areas deep inside caves, and hydrothermal vents at the bottom of the ocean. Factors that affect it include: -The distance and tilt between the earth and the sun- this produces temperatures that are conducive to life and causes the seasons. -Climate, daily weather, and erosion- these change the land and the organisms on and in it. -Earthquakes, tornadoes, volcanoes, tsunamis, and other natural phenomena- these all change the land. -Chemical erosion- this changes the composition of rocks and organic materials, as well as how bacteria and single-celled organisms break down organic and inorganic materials.

compare and contrast physical and chemical properties and changes

Both physical changes and chemical reactions are everyday occurrences. Physical changes do not result in different substances, For example, when water becomes ice it has undergone a physical change, but not a chemical change. It has changed its form, but not its composition. Ice is water. Chemical properties are concerned with the constituent particles that make up the physicality of a substance. Chemical properties are apparent when chemical changes occur. The chemical properties of a substance are influenced by its electron configuration, which is determined in part by the number of protons in the nucleus (the atomic number). Carbon, for example, has 6 protons and 6 electrons. It is an element's outermost valence electrons that mainly determine its chemical properties. Chemical reactions may release or consume energy.

compare and contrast hydrocarbons and carbohydrates

Carbon is an element found in all living things. Two types of carbon molecules that are essential to life are hydrocarbons and carbohydrates. Hydrocarbons, composed only of hydrogen and carbon, are the simplest organic molecules. The simplest of these is methane, which has one carbon atom and four hydrogen atoms. Methane is produced by the decomposition of animal or vegetable matter, and is part of petroleum and natural gas. Carbohydrates are compounds made of hydrogen, carbon, and oxygen. There are three types of these macromolecules (large molecules): -Sugars are soluble in water and, although they have less energy than fats, provide energy more quickly -Starches, insoluble in water, are long chains of glucose that act as reserve substances. Potatoes and cereals are valuable foods because they are rich in starch. Animals retain glucose in their cells as glycogen, a special type of starch. -Cellulose, composed of glucose chains, makes up the cells and tissues of plants, It is one of the most common organic materials.

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. The equation for the formation of water from hydrogen and oxygen, for example, is 2H₂(g) + O₂(g) → 2H₂O(l ). The 2 preceding hydrogen and water is the coefficient, which means there are 2 moles of hydrogen and 2 of water. There is 1 mole of oxygen, which does not have to be indicated with the number 1. In parentheses, g stands for gas, l stands for liquid, s stands for solid, and aq stands for aqueous solution (a substance dissolved in water). 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 bils 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 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 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.

describe the chloroplasts of plant cells

Chloroplasts, which make plants green, are the food producers of a plant cell. They differ from an animal cell's mitochondria, which break down sugars and nutrients. Photosynthesis occurs when the energy from the sun hits a chloroplast and the chlorophyll uses that energy to combine carbon dioxide and water to make sugars and oxygen. The nutrition and oxygen obtained from plants makes them the basis of all life on earth. A chloroplast has two membranes to contain and protect the inner parts. The stroma is an area inside the chloroplast where reactions occur and starches are created. A thylakoid has chlorophyll molecules on its surface, and a stack of thylakoids is called a granum. The stacks of sacs are connected by stromal lamellae, which act like the skeleton of the chloroplast, keeping all the sacs a safe distance from each other and maximizing the efficiency of the organelle.

define comets, asteroids, and meteoroids

Comets are celestial bodies composed of dust, rock, frozen gases, and ice. Invisible until they near the sun, the heat causes them to emit volatile components in jets of gas and dust. The coma is the comet's fog-like envelope that glows as it reflects sunlight and releases radiation. Solar winds blow a comet away from the sun and give it a tail of dust or electrically charged molecules. Each orbit of a comet causes it to lose matter until it breaks up or vaporizes into the sun. Asteroids are irregularly-shaped boulders, usually less than 60 miles in diameter, that orbit the sun. Most are made of graphite; about 25% are silicates, or iron and nickel. Collisions or gravitational forces can cause them to fly off and possibly hit a planet. Meteoroids are fragments of asteroids of various sizes. If they come through earth's atmosphere, they are called meteors or shooting stars. If they land on earth, they are called meteorites, and create craters on impact (such as the Barringer Crater in Arizona).

explain how to draw a conclusion after an experiment

Conclusions are based on data analysis and background research. The scientist has to take a hard look at the results of an experiment and check the accuracy of the data to draw preliminary conclusions. These should be compared to the background research to find out if the preliminary conclusion can be supported by previous research experiments. If the results do not support the hypothesis, or if they are contrary to what the background research predicted, then further research is needed. The focus should be on finding a reason for the different results. Finally, the scientist provides a discussion of finding that includes a summary of the results of the experiment, a statement as to whether the hypothesis was proven or disproven, a statement of the relationship between the independent and dependent variable, a summary and evaluation of the procedures of the experiment (including comments about successes and effectiveness), and suggestions for changes/modifications in procedures for further studies.

identify the characteristics of Earth's moon

Earth's moon is the closest celestial body to earth. Its proximity has allowed it to be studied since the invention of the telescope. As a result, its landforms have been named after astronomers, philosophers, and other scholars. Its surface has many craters created by asteroids since it has no protective atmosphere. These dark lowlands looked like seas to early astronomers, but the vast majority of the moon's water is frozen in spots not easily visible to us from Earth, especially the poles. These impact craters and depressions actually contain solidified lava flows. The bright highlands were thought to be continents, and were named terrae. The rocks of the moon have been pounded by asteroids so often that there is a layer of rubble and dust called the regolith. Also because there is no protective atmosphere, temperatures on the moon vary widely, from -255°F to 265°F.

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 batter or other voltage source.

explain how molecules are formed

Electrons in an atom can orbit different levels around the nucleus. They can absorb or release energy, which can change the location of their orbit or even allow them to break free from the atom. The outermost layer is the valence layer, which contains the valence electrons. The valence layer tends to have or share eight electrons. Molecules are formed by a chemical bond between atoms, a bond which occurs at the valence level. Two basic types of bonds are ionic and covalent. An ionic bond is formed when at atom transfers an electron to another atom. A covalent bond is formed when atoms share electrons. A hydrogen bond is a weak bond between a hydrogen atom of one molecule and an electronegative atom (such as nitrogen, oxygen, or fluorine) of another molecule. The Van der Waals force is a weak force between molecules. This type of force is much weaker than actual chemical bonds between atoms.

explain the difference between atoms and molecules

Elements from the periodic table such as hydrogen, carbon, iron, helium, mercury, and oxygen are atoms. Atoms combine to form molecules. For example, two atoms of hydrogen (H) and one of oxygen (O) combine to form one molecule of water (H₂O).

describe erosion

Erosion is the process that breaks down matter, whether it is a rock that is broken into pebbles or mountains that are rained on until they become hills. Erosion always happens in a down-slope direction. The erosion of land by weather or breaking waves is called denudation. Mass wasting is the movement of masses of dirt and rock form one place to another. This can occur in two ways: mechanical (such as breaking a rock with a hammer) or chemical (such as pouring acid on a rock to dissolve it). If the material changes color, it indicates that a break down was chemical in nature. Whatever is broken down must go somewhere, so erosion eventually builds something up. For example, an eroded mountain ends up in a river that carries the sediment toward the ocean, where it builds up and creates a wetland or delta at the mouth of the river.

describe the structure of the nucleus and mitochondria in eukaryotic cells

Eukaryotic cells have a nucleus, a big dark spot floating somewhere in the center that acts like the brain of the cell by controlling eating, movement, and reproduction. A nuclear envelope surrounds the nucleus and its contents, but allows RNA and proteins to pass through. Chromatin, made up of DNA, RNA, and nuclear proteins, is present in the nucleus. The nucleus also contains a nucleolus made of RNA and proteins. Mitochondria are very small organelles that take in nutrients, break them down, and create energy for the cell through a process called cellular respiration. There might be thousands of mitochondria depending on the cell's purpose. A muscle cell needs more energy for movement than a cell that transmits nerve impulses, for example. Mitochondria have two membranes: a cover and the inner cristae that folds over many times to increase the surface work area. The fluid inside the mitochondria, the matrix, is full of water and enzymes that take food molecules and combine them with oxygen so they can be digested.

discuss Newton's first two laws of motion

First law: An object at rest or in motion remains 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. Second law: An object's acceleration is directly 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 the net force acting 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.

explain how fossil and rock records can reveal changes in the earth's history

Fossils can show how animal and plant life have changed or remained the same over time. For example, fossils have provided evidence of the existence of dinosaurs even though they no longer roam the earth, and have also been used to prove that certain insects have been around forever. Fossils have been used to identify four basic eras: Proterozoic, the age of primitive life; Paleozoic, the age of fishes; Mesozoic, the age of dinosaurs; and Cenozoic, the age of mammals. Most ancient forms of life have disappeared, and there are reference tables that list when this occurred. Fossil records also show the evolution of certain life forms, such as the horse from the eohippus. However, the majority of changes do not involve evolution from simple to complex forms, but rather an increase in the variety of forms.

define freshwater biomes, estuaries, intertidal zones, and subtidal zones

Freshwater biomes are areas of relatively slow-moving water, such as rivers, lakes, and ponds. Since the water is not moving so quickly as to move life forms along, insects and fish have time to grow, and plants have time to attach themselves to the soil. Estuaries are coastline regions where the fresh water from rivers mixes with the salt water of the ocean. This mix is attractive to numerous types of marine life (and birds). It is especially suitable for laying eggs because the water is nearly stagnant and its brackishness hides newborn fish. The intertidal zone is the space on the coastline that is under water during high tide and dry during low tide. It is usually rocky, and contains abundant amounts of algae, small marine life, and many birds looking for food. The subtidal zone, which may have large sandy plains, is always under water near the coast. Coral reefs and most of the world's fish are here because the waves create abundant life-sustaining oxygen in the water.

discuss friction

Friction is a force that arises as a resistance to motion where two surfaces are in contact. The maximum magnitude of the frictional force (f) can be calculated as f = F꜀μ, where F꜀ is the contact force between the two objects and μ is a coefficient of friction based on the surfaces' material composition. Two types of friction are static and kinetic. To picture these concepts, imagine a book resting on a table. The force of its 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 (f) 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 (because the frictional coefficient for static friction is larger), 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 genetics, genes, and chromosomes

Genetics is the science devoted to the study of how characteristics are transmitted from one generation to another. In the 1800s, Gregor Mendel discovered the three laws of heredity that explain how genetics works. Genes are the hereditary units of material that are transmitted from one generation to the next. They are capable of undergoing mutations, can be recombined with other genes, and can determine the nature of an organism, including its color, shape, and size. Genotype is the genetic makeup of an individual based on one or more characteristics, while phenotype is the external manifestation of the genotype. For example, genotype can determine hair color, and phenotype is the actual color of the hair. Chromosomes are the structures inside the nucleus of a cell made up primarily of deoxyribonucleic acid (DNA) and proteins. The chromosomes carry the genes. The numbers vary according to the species, but they are always the same for each species. For example, the human has 26 chromosomes, and the water lily has 112.

list the geological eras and their dates

Geologists divide the history of the earth into units of time called eons, which are divided into eras, then into periods, then into epochs, and finally into ages. Dates are approximate of course, and there may be variations of a few million years. (Million years ago is abbreviated as Ma). Some of the most commonly known periods are: -Hadean Period- about 4.5 to 3.8 billion years ago -Archaean Period- 3.8 to 2.5 billion years ago -Proterozoic Period- 2.5 billion to 542 Ma -Cambrian Period- 542 to 488 Ma -Ordovician Period- 488 to 443 Ma -Silurian Period- 443 to 416 Ma -Devonian Period- 416 to 359 Ma -Carboniferous Period- 359 to 290 Ma -Permian Period- 290 to 248 Ma -Triassic Period- 251 to 200 Ma -Jurassic Period- 200 to 150 Ma -Cretaceous Period- 150 to 65 Ma -Paleogene Period- 65 to 28 Ma -Neogene Period- 28 to 2 Ma -Quaternary Period- about 2 Ma to the present

explain how geologists match rocks and geologic events in one place with those of another

Geologists physically follow rock layers from one location to another by a process called "walking the outcrop." Geologists walk along the outcropping to see where it goes and what the differences and similarities of the neighboring locations they cross are. Similar rock types or patterns of rock layers that are similar in terms of thickness, color, composition, and fossil remains tell geologists that two locations have a similar geologic history. Fossils are found all over the earth, but are from a relatively small time period in earth's history. Therefore, fossil evidence helps date a rock layer, regardless of where it occurs. Volcanic ash is a good time indicator since ash is deposited quickly over a widespread area. Matching the date of an eruption to the ash allows for a precise identification of time. Similarly, the meteor impact at the intersection of the Cretaceous and Tertiary Periods left a time marker. Wherever the meteor's iridium content is found, geologists are able to date rock layers.

describe the formation and types of glaciers

Glaciers start high in the mountains, where snow and ice accumulate inside a cirque ( a small semicircular depression). The snow becomes firmly packed into masses of coarse-grained ice that are slowly pulled down a slope by gravity. Glaciers grow with large amounts of snowfall and retreat (diminish) if warm weather melts more ice than can be replaced. Glaciers once covered large areas of both the northern and southern hemispheres with mile-thick ice that carved out valleys, fjords, and other land formations. They also moved plants, animals, and rocks from one area to another. There were two types of glaciers: valley, which produced U-shaped erosion and sharp-peaked mountains; and continental, which moved over and rounded mountain tops and ridges. These glaciers existed during the ice ages, the last of which occurred from 2.5 mil to 12,000 years ago.

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 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 characteristics of gymnosperms, cycads, and conifers

Gymnosperms are plants with vascular systems and seeds but no flowers (flowers are an evolutionary advancement). The function of the seed is to ensure offspring can be produced by the plant by providing a protective coating that lets the plant survive for long periods until it germinates. It also stores food for the new plant to use until it can make its own. Seeds can be spread over a wide area. Cycads are sturdy plants with big, waxy fronds that make them look like ferns or palms. They can survive in harsh conditions if there is warm weather. For reproduction, they have big cones located in the center of the plant. The female plant grows a fruit in the middle of the stem. Conifers are trees that thrive in northern latitudes and have cones. Examples of conifers are pine, cedar, redwood, and spruce. Conifers are evergreens because they have needles that take full advantage of the sun year round. They are also very tall and strong because of the chemical substance xylem in their systems.

compare and contrast heat and temperature

Heat is energy transfer (other than direct work) from one body or system to another due to thermal contact. Everything tends to become less organized and less orderly over time (entropy). In all energy transfers, therefore, the overall result is that the energy is spread out uniformly. This transfer of heat energy from hotter to cooler objects is accomplished by conduction, radiation, or convection. Temperature is a measurement of an object's stored heat energy. More specifically, temperature is the average kinetic energy of an object's particles. When the temperature of an object increases and its atoms move faster, kinetic energy also increases. Temperature is not energy since it changes and is not conserved. Thermometers are used to measure temperature.

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 (the 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, its hydrophobic qualities, and its ability to float in its solid form. Hydrogen bonds are also an important component of proteins, nucleic acids, and DNA.

define the following components of scientific experimentation: hypothesis, theory, law, control, constants, independent variables, and dependent variables

Hypothesis- tentative supposition about a phenomenon (or a fact or a set of facts) made in order to examine and test its logical or empirical consequences through investigation or methodological experimentation. Theory- a scientifically proven, general principle offered to explain phenomena. A theory is derived from a hypothesis and verified by experimentation and research. Scientific law- generally accepted conclusion about a body of observations to which no exceptions have been found. Scientific laws explain things, but do not describe them. Control- a normal, unchanged situation used for comparison against experimental data. Constants- factors in an experiment that remain the same. Independent variables- factors, traits, or conditions that are changed in an experiment. A good experiment has only one independent variable so that the scientist can track one thing at a time. The independent variable changes from experiment to experiment. Dependent variables- changes that result from variations in the independent variable.

describe inquiry-based science in the classroom

If learning in the science classroom is inquiry-based, children should see themselves as being involved in the process of learning. They should feel free to express curiosity and skepticism, change ideas and procedures, take risks, and exchange information with their classmates. Inquiry-based learning in science begins with observations of details, sequences, events, changes, similarities and differences, etc. Observations are followed by investigations based on scientific standards and safety that are designed by students. Designs should allow for verification, extension, or dismissal of ideas. Investigations should involve choosing tools, handling materials, measuring, observing, and recording data. The results of an investigation can take the form of a journal, report, drawing, graph, or chart. The summary of the observations and investigations should include explanations, solutions, and connections to other ideas, as well as further questions, an assessment of the quality of the work, a description of any problems encountered, and a description of the strengths and weaknesses of the investigation. Finally, students should reflect together about the lessons learned from the investigation.

describe the three major subdivisions of rock: igneous, metamorphic, and sedimentary

Igneous (magmatites)- formed from the cooling of liquid magma. In the process, minerals crystallize and amalgamate. If solidification occurs deep in the earth (plutonic rock), the cooling process is slow. This allows for the formation of large crystals, giving rock a coarse-grained texture (granite). Quickly cooled magma has a glassy texture (obsidian). Metamorphic- rock material that melts under conditions of high temperature and pressure within the earth's crust and changes structure to transition/metamorphize into a new type of rock with different minerals. If the minerals appear in bands, the rock is foliated. Examples include marble (unfoliated) and slate (foliated). Sedimentary- the most common type of rock on earth. Formed by sedimentation, compaction, and then cementation of many small particles of mineral, animal, or plant material. There are three types of sedimentary rocks: clastic, clay, and sand that came from disintegrated rocks; chemical (rock salt and gypsum), formed by evaporation of aqueous solutions; and biogenic (coal), formed from animal or plant remnants.

name the planets and describe them in relation to their orbits

In order of their distance from the sun (closest to furthest away), the planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto (which is a dwarf planet). All the planets revolve around the sun, which is an average-sized star in the spiral Milky Way galaxy. They revolve in the same direction in nearly circular orbits. If the planets were viewed by looking down from the sun, they would rotate in a counter-clockwise direction. Pluto's orbit is so highly inclined at 18 degrees that at times its ellipse is nearer to the sun than to its neighbor, Neptune. All the planets are in or near the same plane, called the ecliptic, and the axis of rotation is nearly perpendicular to the ecliptic. The exceptions are Uranus and Pluto, which are tipped on their sides.

identify the purpose of studying interactions among humans, natural hazards, and the environment in science class

In science class, students will learn that humans can be affected by factors from both their natural environments and technology they use in their daily lives. Factors can be positive or negative, so students need to learn how to prepare for, respond to, and analyze and evaluate the consequences of environmental occurrences over a long period of time. Natural disasters are a negative experience, but so are human-made disasters such as pollution and deforestation. Students need to understand that science is involved in the interactions between the human population, natural hazards, and the environment. They should know that the aim of science is to make these interactions balanced and positive. Science is a discipline that can help find ways to increase safety during and remediate after natural disasters, advance technology in an environmentally safe manner, prevent and cure diseases, and remediate the environmental damage that has already been done.

outline the characteristics of the three types of invertebrates: marine, freshwater, and terrestrial

Invertebrates are animals with no internal skeletons. They can be divided into three groups: Marine invertebrates- invertebrates living in oceans and seas. Marine invertebrates include sponges, corals, jellyfish, snails, clams, octopuses, squids, and crustaceans, none of which live on the surface. Freshwater invertebrates- invertebrates living in lakes and rivers. Freshwater invertebrates include worms on the bottom, microscopic crustaceans, and terrestrial insect larvae that live in the water column, but only where there is no strong current. Some live on the surface of the water. Terrestrial invertebrates- invertebrates living on dry ground. Terrestrial invertebrates include insects, mollusks (snails, slugs), arachnids, and myriapods (centipedes and millipedes). Terrestrial invertebrates breathe through a series of tubes that penetrate into the body (trachea) and deliver oxygen into tissues. Underground terrestrial invertebrates are generally light-colored with atrophied eyes and no cuticle to protect them from desiccation. They include worms that live underground and in caves and rock crevices. This group also includes insects such as ants that create colonies underground.

explain why it is important to study science in the context of personal and social perspectives

Learning must be relevant, so when students study science in the context of personal and social perspectives, they see the practical application of the textbook knowledge. They are given an understanding of the issues around them that can be solved by science and the means to act on those issues. Science should be taught within the social context of history so that students can see where society has been and how far it has come thanks to scientific advancements related to tools, medicine, transportation, and communication. Students should also understand how these advances developed in response to resources, needs, and values. Students need to review the process of scientific inquiry through the centuries to get a sense of the benefits of intellectual curiosity, the inter-relatedness of science, and the development of civilization. Students should question the role science has played in the development of various cultures by considering how computers, refrigeration, vaccines, microscopes, fertilizers, etc. have improved the lives of people.

list some of the biological, chemical, and physical properties that contribute to the earth's life-sustaining system

Life on Earth is dependent on: -All three states of water- gas (water vapor), liquid, and solid (ice) -A variety of forms of carbon, the basis of life (carbon-based units) -In the atmosphere, carbon dioxide in the forms of methane and black carbon soot produce the greenhouse effect that provides a habitable atmosphere -The earth's atmosphere and electromagnetic field, which shield the surface from harmful radiation and allow useful radiation to go through -The earth's relationship to the sun and moon, which creates the four seasons and the cycles of plant and animal life -The combination of water, carbon, and nutrients, which provides sustenance for life and regulates the climate system in a habitable temperature range with non-toxic air

discuss visible light as part of the electromagnetic spectrum

Light is the portion of the electromagnetic spectrum that is visible because of its 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 on the spectrum. The wavelengths of visible light cover a range form 380 nm (violet) to 760nm (red). Different wavelengths correspond to different colors.

discuss what matter is and describe its properties

Matter refers to substances that have mass and occupy space (or volume). The traditional definition of matter describes it as having three states: solid, liquid, and gas, These different states are caused by differences in the distances and angles between molecules or atoms, which result in differences in the energy that binds them. Solid structures are rigid or nearly rigid and have strong bonds. Molecules or atoms of liquids move around and have weak bonds, though not weak enough to readily break. Molecules or atoms of gases move almost independently of each other, are typically far apart, and do not form bonds. The current definition of matter describes it as having four states. The fourth is plasma, which is an ionized gas that has some electrons that are described as free because they are not bound to an atom or molecule.

describe microbes (microorganisms)

Microbes are the smallest, simplest, and most abundant organisms on earth. Their numbers are incalculable, and a microscope is required to see them. There is a huge variety of microbes, including bacteria, fungi, some algae, and protozoa. Microbes can be harmful or helpful. Microbes can be heterotrophic (eat other things) or autotrophic (make food for themselves). They can be solitary or colonial, sexual or asexual. Examples include mold, a multi-cellular type of fungus, and yeasts, which are single-celled but may live in colonies. A mushroom is a fungus that lives as a group of strands underground called hyphae that decompose leaves or bark on the ground. When it reproduces, it develops a mushroom whose cap contains spores. Mold is a type of zygote fungi that reproduces with a stalk, but releases zygospores. Good bacteria can be those that help plants absorb the nitrogen needed for growth or help grazing animals break down the cellulose in plants. Some bad bacteria are killed by the penicillin developed from a fungus.

explain the process of mitotic cell replication

Mitosis is the duplication of a cell and all its parts, including the DNA, into two identical daughter cells. There are five phases in the life cycle of a cell: -Prophase- the process of duplicating everything in preparation for division. -Metaphase- the cell's different pieces align themselves for the split. The DNA lines up along a central axis and the centrioles send out specialized tubules that connect to the centromere. The centromere has two strands of a chromosome (condensed DNA) attached to it. -Anaphase- half of the chromosomes go one way and half go the other. -Telophase- when the chromosomes get to the side of the cell, the cell membrane closes in and splits the cell into two pieces. This results in two separate cells, each with half of the original DNA. -Interphase- the normal state of the cell, or the resting stage between divisions. During this stage, the cell duplicates nucleic acids in preparation for the next division.

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 a 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 flows. A roller coaster car requires work to be performed to transport it to a point where it has potential energy (the top of a sloping track). 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 the traditional earth science disciplines

Modern science is approaching the study of the earth in an integrated way that sees the earth as an interconnected system that is impacted by humankind and, therefore, must include social dimensions. Traditionally, the following were the earth science disciplines: -Geology- the study of the origin and structure of the earth and of the changes it has undergone and is in the process of undergoing. Geologists work from the crust inward. -Meteorology- the study of the atmosphere, including atmospheric pressure, temperature, clouds, winds, precipitation, etc. It is also concerned with describing and explaining weather. -Oceanography- the study of the oceans, which includes studying their extent and depth, the physics and chemistry of ocean waters, and the exploitation of their resources. -Ecology- the study of living organisms in relation to their environment and to other living things. It is the study of the interrelations between the different components of the ecosystem.

define motion and displacement

Motion is a change in the location of an object, and is the result of an unbalanced net force acting 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 a 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 traverses the same path in the opposite direction, its displacement is -10 cm. 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 the other. 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 (1.5 V) battery, a small light bulb, and a piece of copper wire to create a circuit to light the bulb.

provide the definition of a planet as agreed upon by the International Astronomical Union in 2006 and briefly describe the solar system

On August 24, 2006, the International Astronomical Union redefined the criteria a body must meet to be classified as a planet, stating that the following conditions must be met: -A planet orbits around a star and is neither a star nor a moon -Its shape is spherical due to its gravity -It has "cleared" the space of its orbit A dwarf planet such as Pluto doesn't meet the third condition. Small solar system bodies such as asteroids and comets meet only the first condition. The solar system developed about 4.6 bil years ago out of an enormous cloud of dust and gas circling around the sun. Four rocky planets orbit relatively close to the sun. Their inside orbit is separated from the outside orbit of the four, larger gaseous planets by an asteroid belt. Pluto, some comets, and several small objects circle in the Kuiper belt outside Neptune's orbit. The Oort cloud, composed of icy space objects, encloses the planetary system like a shell.

describe the field of paleontology

Paleontology is the study of prehistoric plant and animal life through the analysis of fossil remains. These fossils reveal the ecologies of the past and the path of evolution for both extinct and living organisms. A historical science, paleontology seeks information about the identity, origin, environment, and evolution of past organisms and what they can reveal about the past of the earth as a while. Paleontology explains causes as opposed to conducting experiments to observe effects. It is related to the fields of biology, geology, and archaeology, and is divided into several sub-disciplines concerned with the types of fossils studies, the process of fossilization, and the ecology and climate of the past. Paleontologists also help identify the composition of the earth's rock layers by the fossils that are found, thus identifying potential sites for oil, mineral, and water extraction.

compare and contrast passive and active transport

Passive transport within a cell does not require energy and work. For example, when there is a large concentration difference between the outside and the inside of the cell, the pressure of the greater concentration, not energy, moves molecules across the lipid bilayer into the cell. Another example of passive transport is osmosis which is the movement of water across a membrane. Too much water in a cell can cause it to burst, so the cell moves ions in and out to help equalize the amount of water. Active transport is when a cell uses energy to move individual molecules across the cell membrane to maintain a proper balance. Proteins embedded in the lipid bilayer do most of the transport work. There are hundreds of different types of proteins because they are specific. For instance, a protein that moves glucose doesn't move calcium. The activity of these proteins can be stopped by inhibitors or poisons, which can plug up or destroy a protein.

define pitch, loudness, sound intensity, timbre, and oscillation

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

explain how plants manufacture food

Plants are the only organisms capable of transforming inorganic material from the environment into organic matter by using water and solar energy. This transformation is made possible by chloroplasts, flat structures inside plant cells. Chloroplasts, located primarily in the leaves, contain chlorophyll (the pigment capable of absorbing light and storing it in chemical compounds), DNA, ribosomes, and numerous enzymes. Chloroplasts are surrounded by a membrane. The leaves of plants are the main producers of oxygen, which helps purify the air. The chlorophyll in chloroplasts is responsible for the light, or luminous, phase of photosynthesis. The energy it absorbs breaks down water absorbed through the roots into hydrogen and oxygen to form ATP molecules that store energy. In the dark phase, when the plant has no light, the energy molecules are used to attach carbon dioxide to water and form glucose, a sugar.

list ways that the earth's geologic history can be sequenced from the fossil and rock record

Reference tables are used to match specimens and time periods. For example, the fossil record has been divided into time units of the earth's history. Rocks can therefore be dated by the fossils found with them. There are also reference tables for dating plate motions and mountain building events in geologic history. Since humans have been around for a relatively short period of time, fossilized human remains help to affix a date to a location. Some areas have missing geologic layers because of erosion or other factors, but reference tables specific to a region can list what is complete or missing. The theory of uniformitarianism assumes that geologic processes have been the same throughout history. Therefore, the way erosion or volcanic eruptions happen today is the same as the way these events happened mils of years ago because there is no reason for them to have changed. Therefore, knowledge about current events can be applied to the past to make judgements about events in the rock record.

explain risk and benefit analysis as studied in the personal and social perspectives of science

Risk analysis considers the type of hazard and estimates the number of people who might be exposed and the number likely to suffer consequences. The results are used to determine options for reducing or eliminating risks. For example, the Center for Disease Control must analyze the risk of a certain new virus strain causing a pandemic, how many people and what age groups need to be vaccinated first, and what precautions can be taken to guard against the spread of the disease. Risk and benefit analysis involves having students consider the dancers of natural (major storms), chemical (pollution), biological (pollen and bacteria), social (occupational safety and transportation), and personal (smoking, dieting, and drugs) hazards. Students then use a systematic approach to think critically about these hazards, apply probability estimates to the risks, and compare them to estimated and perceived personal and social benefits.

explain the function of roots, stems, and leaves

Roots are structures designed to pull water and minerals from soil or water. In large plants such as trees, the roots usually go deep into the ground to not only reach the water, but also to support and stabilize the tree. There are some plant species that have roots above ground, and there are also plants called epiphytes that live in trees with their roots clinging to the branches. Some roots, like carrots and turnips, serve as food. Roots are classified as primary and lateral (like a trunk and branches). The apical meristem is the tip of a root or shoot that helps the plant increase in length. Root hairs are fuzzy root extensions that help with the absorption of water and nutrients. The majority of the plant above ground is made up of the stems (trunk and branches) and leaves. Stems transport food and water and act as support structures. Leaves are the site of photosynthesis. and are connected to the rest of the plant by a vascular system,

describe science as a series of processes

Science is not just the steps of experimentation. While the process of posing a question, forming a hypothesis, testing the hypothesis, recording data, and drawing a conclusion is at the heart of scientific inquiry, there are other processes that are important as well. Once the scientist has completed the testing of a hypothesis and possibly come up with a theory, the scientists should then go through the process of getting feedback from colleagues, publishing an article about the work in a peer-reviewed journal, or otherwise reporting the results to the scientific community, replicating the experiment for verification of results (by the original scientist or others), and developing new questions. Sciences is not just a means of satisfying curiosity, but is also a process for developing technology, addressing social issues, building knowledge, and solving everyday problems.

name the different types of climates and identify the factors that affect climates

Scientists have determined the following different types of climates: -Polar (ice caps) -Polar (tundra) -Subtropical (dry summer) -Subtropical (dry winter) -Subtropical (humid) -Subtropical (marine west coast) -Subtropical (Mediterranean) -Subtropical (wet) -Tropical (monsoon) -Tropical (savannah/grasslands) -Tropical (wet) Several factors make up and affect climates, including: -Temperature -Atmospheric pressure -Number of clouds and amount of dust or smog -Humidity -Winds The moistest and warmest of all the climates is that of the tropical rainforest. It has daily convection thunderstorms caused by the surface daytime heat and the high humidity, which combine to form thunderclouds.

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 enables 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 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.

discuss different types of energy

Some discussions of energy consider only two types of energy: kinetic energy (the energy of motion) and potential energy (which depends on relative position or orientation). There are, however, other types of energy. Electromagnetic waves, for example, are a type of energy contained by a field. Another type of potential energy is electrical energy, which is the energy it takes to pull apart positive and negative electrical charges. Chemical energy refers to the manner in which atoms form into molecules, and this energy can be released or absorbed when molecules regroup. Solar energy comes in the form of visible light and non-visible light, such as infrared and ultraviolet rays. Sound energy refers to the energy in sound waves.

list some properties of salts

Some properties of salts are that they are formed form 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 (NaCl), sodium bisulfate, potassium dichromate (K₂Cr₂O₇), and calcium chloride (CaCl₂). Calcium chloride is used as a drying agent, and may be used to absorb moisture when freezing mixtures. Potassium nitrate (KNO₃ is used to make fertilizer and in the manufacture of explosives. Sodium nitrate (NaNO₃) is also used in the making of fertilizer. Baking soda (sodium bicarbonate) is a salt, as are Epsom salts [magnesium sulfate (MgSO₄)]. Salt and water can react to form a base and an acid. This is called a hydrolysis reaction.

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. Waves of sound energy move outward in all directions from the 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. Different sounds have different wavelengths. Sound is a form of kinetic energy.

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 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 as 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.

explain how the rock record can help determine the order in which geologic events occurred

The Law of Superposition logically assumes that the bottom layer of a series of sedimentary layers is the oldest, unless it has been overturned or older rock has been pushed over it. In addition, since igneous intrusions can cut through or flow above other rocks, these other rocks are older. For example, molten rock (lava) flows out over already present, older rocks. Another guideline for the rock record is that rock layers are older than the folds and faults in them because the rocks must exist before they can be folded or faulted. If a rock contains atomic nuclei, reference tables of the half lives of commonly used radio isotopes can be used to match the decay rate of known substances to the nuclei in a rock, and thereby determine its age. Ages of rocks can also be determined from contact metamorphism, the re-crystallization of pre-existing rocks due to changes in physical and chemical conditions, such as heat, pressure, and chemically active fluids that might be present in lava or polluted waters.

define the Terrestrial Planets and the Jovian Planets, and describe the mass of the planets in the solar system

The Terrestrial Planets are Mercury, Venus, Earth, and Mars. These are the four planets closest to the sun. They are called terrestrial because they all have a compact, rocky surface similar to the Earth's. Venus, Earth, and Mars have significant atmospheres, but Mercury has almost no atmosphere. The Jovian Planets are Jupiter (the largest planet), Saturn, Uranus, and Neptune. They are called Jovian (Jupiter-like) because of their huge sizes in relation to the Earth and their gaseous nature like Jupiter's. Although gas giants, some or all of the Jovian Planets may have small, solid cores. Pluto does not have the characteristics necessary to fit into either the Terrestrial or the Jovian group. The sun represents 99.85% of all the matter in our solar system. Combined, the planets make up only 0.135% of the mass of the solar system, with Jupiter having twice the mass of all the other planets combined. The remaining 0.015% of the mass comes from comets, planetary satellites, asteroids, meteoroids, and interplanetary medium.

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 toward it. An electron within the force of the field is pulled toward 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 the two objects. Electric charge is measured with the unit Coulomb (C). It is the amount of charge moved in one second by a steady current of one ampere (1C = 1A X 1s)

explain the role of a cell and describe its basic contents

The cell is the basic organizational unit of all living things. Each piece within a cell has a function that helps organisms grow and survive. There are many types of cells, but cells are unique to each type of organism. The one thing that all cells have in common is a membrane, which is comparable to a semi-permeable plastic bag. The membrane is composed of phospholipids. There are also some transport holes, which are proteins that help certain molecules and ions move in and out of the cell. The cell is full of a fluid called cytoplasm or cytosol. Within the cell are a variety of organelles, groups of complex molecules that help a cell survive, each with its own unique membrane that has a different chemical makeup from the cell membrane. The larger the cell, the more organelles it needs to live.

describe the components of each earth system science

The complex and interconnected dynamics of the continents, atmosphere, oceans, ice, and life forms are the subject of earth system science. These interconnected dynamics require an interdisciplinary approach that includes chemistry, physics, biology, mathematics, and applied sciences in order to study the Earth as an integrated system and determine (while considering human impact and interaction) the past, present, and future states of the earth. Scientific inquiry in this field includes exploration of: -Extreme weather events as they pertain to a changing climate -Earthquakes and volcanic eruptions as they pertain to tectonic shifts -Losses in biodiversity in relation to the changes in the earth's ecosystems -Causes and effects in the environment -The sun's solar variability in relation to the earth's climate -The atmosphere's increasing concentrations of carbon dioxide and aerosols -Trends in the earth's systems in terms of changes and their consequences

describe the layers of the earth

The earth has several distinct layers, each with its own properties: -Crust- the outermost layer of the earth that is comprised of the continents and the ocean basins. It has a variable thickness (35-70 km in the continents and 5-10 km in the ocean basins) and is composed mostly of alumino-silicates. -Mantle- about 2900 km thick and made up of ferro-magnesium silicates. It is divided into an upper and lower mantle. Most of the internal heat of the earth is located in the mantle. Large convective cells circulate heat, and may cause plate tectonic movement. -Core- separated into the liquid outer core and the solid inner core. The outer core is 2300 km thick (composed mostly of nickel-iron alloy), and the inner core is 12 km thick (composed of almost entirely iron). The earth's magnetic field is thought to be controlled by the liquid outer core.

describe the composition of Earth's atmosphere

The earth's atmosphere is 79% nitrogen, 20% oxygen, and 1% other gases. The oxygen was originally produced almost entirely by algae-type plants. The atmosphere has four layers: -Troposphere- the layer closest to the earth where all weather takes place. It is the region that contains rising and falling packets of air. Air pressure at sea level is 0.1 atmospheres, but the top of the troposphere is about 10% of that amount. -Stratosphere- in this layer, air flow is mainly horizontal. The upper portion has a thin layer of concentrated ozone (a reactive form of oxygen) that is largely responsible for absorbing the sun's ultraviolet rays. -Mesosphere- the coldest layer. Temperatures drop to -100°C at the top. -Thermosphere- divided into the lower ionosphere and the higher exosphere. This layer is very thin and has many ionized atoms with a net electrical charge. The aurora and Van Allen Belts are here. This layer also absorbs the most energetic photons from the sun and reflects radio waves, enabling long distance radio communication.

discuss the electromagnetic spectrum

The electromagnetic spectrum is defined by frequency (f) and wavelength (λ). 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 the formula f = c/λ, where c is the speed of light (about 300 mil meters per second). 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 10⁵ meters, while their frequencies range from about 10³ to 10¹¹ Hz.

briefly outline the development of life on earth according to time periods

The evolution of life on earth is believed to have occurred as follows: -Igneous rocks formed (Hadean) -The continents formed (Archaean Eon) -One-celled creatures such as hydras, jellyfish, and sponges appeared about 600 Ma -Flatworms, roundworms, and segmented worms appeared about 550 Ma -Moss, arthropods, octopus, and eels appeared (Cambrian Period) -Mushrooms, fungi, and other primitive plants appeared; sea animals began to use calcium to build bones and shells (Ordovician Period) -Fish with jaws appeared (Silurian Period) -Fish developed lungs and legs (frogs) and went on land; ferns appeared (Devonian Period) -Reptiles developed the ability to lay eggs on land and pine trees appeared (Carboniferous Period) -Dinosaurs dominated the land during the Triassic and Jurassic Periods -Flying insects, birds, and the first flowering plants appeared; dinosaurs died out (Cretaceous Period) -Mammals evolved and dominated; grasses became widespread (50 Ma) -Hominids appeared more than 2 Ma

explain the role of producers, consumers, and decomposers in the food chain

The food chain, or food web, is a series of events that happens when one organism consumes another to survive. Every organism is involved in dozens of connections with others, so what happens to one affects the environment of the others. In the food chain, there are three main categories: -Producers- plants and vegetables are at the beginning of the food chain because they take energy from the sun and make food for themselves through photosynthesis. They are food sources for other organisms. -Consumers- there are three levels of consumers: the organisms that eat plants (primary consumers, or herbivores); the organisms that eat the primary consumers (secondary consumers, or carnivores); and, in some ecosystems, the organisms that eat both plants and animals (tertiary consumers, or omnivores). -Decomposers- these are the organisms that eat dead things or waste matter and return the nutrients to the soil, thus returning essential molecules to the producers and completing the cycle.

explain the purpose of the skeletal system

The human body has an endoskeleton, meaning it is inside the body. It is made up of bones instead of the hard plate of exoskeletons or fluids in tubes, which comprise the hydrostatic system of the starfish. The purpose of the skeleton is to support the body, provide a framework to which the muscles and organs can connect, and protect the inner organs. The skull protects the all-important brain and the ribs protect the internal organs from impact. The skeletal system interacts with the muscular system to help the body more, and softer cartilage works with the calcified bone to allow smooth movement of the body. The skeletal system also interacts with the circulatory system in that the marrow inside the bones helps produce both white and red blood cells.

describe the hydrosphere and the hydrologic cycle

The hydrosphere is anything on earth that is related to water, whether it is in the air, on land, or in a plant or animal system. A water molecule consists of only two atoms of hydrogen and one of oxygen, yet it is what makes life possible. Unlike the other planets, earth is able to sustain life because its temperature allows water to be in its liquid state most of the time. Water vapor and ice are of no use to living organisms. The hydrologic cycle is the journey water takes as it assumes different forms. Liquid surface water evaporates to form the gaseous state of a cloud, and then becomes liquid again in the form of rain. This process takes about 10 days if water becomes a cloud. Water at the bottom of the ocean or in a glacier is not likely to change form, even over periods of thousands of years.

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 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.

compare and contrast hunters and prey animals

The interaction between predators and their prey is important to controlling the balance of an ecosystem. Hunters are carnivorous animals at the top of the ecological pyramid that eat other animals. Hunters tend to be territorial, leaving signs to warn others to stay out or risk a fight. Hunters are equipped to capture with claws, curved beaks, spurs, fangs, etc. They try to use a minimum amount of energy for each capture, so they prey on the more vulnerable (the young, the old, and the unwell) when given a choice. Predators never kill more than they can eat. Some hunters have great speed, some stalk, and some hunt in groups. Prey animals are those that are captured by predators for food. They are usually herbivores further down the ecological pyramid. Prey animals have special characteristics to help them flee from predators. They may hide in nests or caves, become totally immobile to escape detection, have protective coloration or camouflage, have warning coloration to indicate being poisonous, or have shells or spikes for protection.

identify some of the interactions of science and technology with society

The interactions of science and technology with society include: -Scientific knowledge and the procedures used by scientists influence the way many people think about themselves, others, and the environment. -Technology influences society through its products and processes. It influences quality of life and the ways people act and interact. Technological changes are often accompanied by social, political, and economic changes. Science and technology contribute enormously to economic growth and productivity. The introduction of the cell phone into society is a perfect example of technology influencing society, quality of life, human interaction, and the economy. -Societal challenges often inspire questions for scientific research, and social priorities often influence research priorities through the availability of research funds. Science and technology have been advanced through the contributions of many different people in a variety of cultures during different time periods in history. Scientists and engineers work in colleges, businesses and industries, research institutes, and government agencies, touching many lives in a variety of settings.

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 force 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 a 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 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.

list the four basic laws of thermodynamics

The laws of thermodynamics are generalized principles dealing with energy and heat. -The zeroth law of thermodynamics states that two objects in thermodynamic equilibrium with a third object are also in thermodynamic equilibrium with each other. Being in thermodynamic equilibrium basically means that different objects are at the same temperature. -The first law deals with conservation of energy. It states that neither mass nor energy can be destroyed; only converted from one form to another. -The second law states that the entropy (the amount of energy in a system that is no longer available for work or the amount of disorder in a system) of an isolated system can only increase. The second law also states that heat is not transferred from a lower-temperature system to a higher-temperature one unless additional work is done. -The third law of thermodynamics states that as temperature approaches absolute zero, entropy approaches a constant minimum. It also states that a system cannot be cooled to absolute zero.

outline the system of classification for living organisms

The main characteristic by which living organisms are classified is the degree to which they are related, not the degree to which they resemble each other. The science of classification is called taxonomy, a difficult science since the division lines between groups is not always clear. Some animals have characteristics of two separate groups. The basic system of taxonomy involves placing an organism into a major kingdom (Moneran, Protist, Fungi, Plants, and Animals), and then dividing those kingdoms into phyla, then classes, then orders, then families, and finally genuses. For example, the family cat is in the kingdom of animals, the phylum of chordates, the class of mammals, the order of carnivores, the family of felidae, and the genus of felis. All species of living beings can be identified with Latin scientific names that are assigned by the worldwide binomial system. The genus name comes first, and is followed by the name of the species. The family cat is felis domesticus. Although not part of taxonomy, behavior is also considered in identifying living beings. For example, birds are identified according to their songs or means of flight.

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 phosphorous, and metal complexes. A metal complex has a central 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 vary water soluble, and crystallize easily. Minerals and silicates are also inorganic compounds.

explain magnetic fields as they related 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 force 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.

describe the functions of the nervous system

The nervous system is divided into two parts: the central nervous system (brain and spinal cord) and the peripheral nervous system (a network of billions of neurons of different types throughout the entire body). The neurons are connected end to end, and transmit electrical impulses to each other. Efferent neurons sent impulses from the central system to the limbs and organs. Afferent neurons receive sensory information and transmit it back to the central system. The nervous system is concerned with senses and action. In other words, it senses something and then acts upon it. An example is a predator sensing prey and attacking it. The nervous system also automatically senses activity inside the body and reacts to stimuli. For example, the first bite of a meal sets the whole digestive system into motion. The nervous system interacts with every other system in the body because all the tissues and organs need instruction, even when individuals are not aware of any activity occurring. For instance, the endocrine system is constantly working to produce hormones or adrenalin as needed.

describe the periodic table and its 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 includes the symbol for the element and its atomic number. The cell for hydrogen, for example, which appears first in the upper left corner, includes and "H" and a "1" above the letter. Elements are ordered by atomic number, left to right, top to bottom.

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 (more than 7) is a base. Urine, stomach acid, citric acid, vinegar, hydrochloric acid, and battery acid are acids. Drain cleaner, soap, baking soda, ammonia, egg whites, and sea water are common bases. 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.

describe the respiratory system, including examples of diseases and interactions with other systems

The respiratory system exchanges gases with the environment. Amphibians exchange gases through their moist skin and fish use gills, but mammals, birds, and reptiles have lungs. The human respiratory system is made up of the nose, mouth, pharynx, trachea, and two lungs. The purpose of the respiratory system is to bring oxygen into the body and expel carbon dioxide. The respiratory system can inhale viruses, bacteria, and dangerous chemicals, so it is vulnerable to toxins and diseases such as pneumonia, which causes the lungs to fil l with fluid until they cannot take in enough oxygen to support the body. Emphysema, often caused by smoking tobacco, destroys the tissues in the lungs, which cannot be regenerated. The respiratory system interacts with the digestive system in that the mouth and pharynx are used to swallow food and drink, as well as to breathe. It interacts with the circulatory system in that it provides fresh oxygen through blood vessels that pass through the lungs. This oxygen is then carried by the circulatory system throughout the body.

outline the characteristics of the vertebrate groups: fish, amphibians, reptiles and birds, and mammals

The vertebrates, animals with an internal skeleton, are divided into four groups: -Fish- the most primitive group, but also the group from which all others evolved. Fish live in water, breathe with gills, are cold-blooded, have fins and scales, and are typically oviparous. Fish typically have either cartilaginous skeletons (such as rays and sharks) or bony skeletons. -Amphibians- the skin of animals in this group is delicate and permeable, so they need water to keep it moist. Amphibians are oviparous. The young start out in water with gills, but the adults use lungs. -Reptiles and birds- the skin of animals in this group has very hard, horn-like scales. Birds have exchanged scales for feathers. Reptiles and birds are oviparous, although birds care for their eggs and reptiles do not. Members have a cloaca, an excretory and reproductive cavity that opens to the outside. Reptiles are cold-blooded, but birds are warm-blooded. -Mammals- these are the most highly evolved vertebrates. Mammals have bodies covered with fur; are warm-blooded, are viviparous, meaning they give birth to live young which are fed with milk from female mammary glands; and are tetrapods (four-limbed). Most live on the ground (except whales and dolphins) and a few fly (bats).

describe the three types of reproduction in mammals

There are three types of mammals when they're classified by how they reproduce: -Monotremes are rare mammals that lay eggs. These were the first mammals, and are more closely related to reptiles than other mammals. Examples include the duck-billed platypus and the spiny anteater. -Marsupials are special mammals. They give birth to live young, but the babies mature in pouches, where they are carried and can feed on milk. Many are found Australia. The isolation of this island continent prevented placental mammals from taking hold. Examples of marsupials include kangaroos, possums, and koalas. -Placental mammals give birth from the females' placenta to live young. The young may be able to walk immediately, or they may need to be carried. They are dependent on parental care for at least a short time. Placental mammals are the dominant form of mammals. Members of this group include cetaceans such as whales and dolphins, which are mammals that evolved but returned to the ocean.

discuss past atomic models and theories

There have been many revisions to theories regarding the structure of atoms and their particles. Part of the challenge in developing an understanding of matter is that atoms and their particles are too small to be seen. It is believed that the first conceptualization of the atom was developed by Democritus in 400 BC. Some of the more notable models are the solid sphere or billiard ball model postulated by John Dalton, the plum pudding or raisin bun model by J.J. Thomson, the planetary or nuclear model by Ernest Rutherford, the Bohr or orbit model by Niels Bohr, and the electron cloud or quantum mechanical model by Louis de Broglie and Erwin Schrodinger. Rutherford directed the alpha scattering experiment that discounted the plum pudding model. The shortcoming of the Bohr model was the belief that electrons orbited in fixed rather than changing ecliptic orbits.

define thermal contact

Thermal contact refers to energy transferred to a body by a means other than work. A system in thermal contact with another can exchange energy with is through the process of heat transfer. Thermal contact does not necessarily involve direct physical contact. Heat is energy that can be transferred from one body or system without work being done. Everything tends to become less organized and less useful over time (entropy). In all energy transfers, therefore, the overall result is that the heat is spread out so that objects are in thermodynamic equilibrium and the heat can no longer be transferred without additional work.

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 300º C. 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, nitro, 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 mil organic compounds.

list the organisms that interfere with cell activity, and then explain how they enter the body and how they cause problems

Viruses, bacteria, fungi, and other parasites may infect plants and animals and interfere with normal life functions, create imbalances, or disrupt the operations of cells. Viruses- These enter the body by inhalation (airborne) or through contact with contaminated food, water, or infected tissues. They affect the body by taking over the cell's protein synthesis mechanism to make more viruses. They kill the host cell and impact tissue and organ operations. Examples of viruses include measles, rabies, pneumonia, and AIDS. Bacteria- These enter the body through breaks in the skin or contaminated food or water, or by inhalation. They reproduce rapidly and produce toxins that kill healthy host tissues. Examples include diphtheria, the bubonic plague, TB, and syphilis. Fungi- These feed on healthy tissues of the body by sending rootlike tendrils into the tissues to digest them extracellularly. Examples include athlete's foot and ringworm. Parasites- These enter the body through the skin, via insect bites, or through contaminated food or water. Examples include tapeworms, malaria, or typhus.

name different types of volcanoes and volcanic mountains

Volcanoes are classified according to their activity level. An active volcano is in the process of erupting or building to an eruption; a dormant volcano has erupted and may erupt again someday but is not currently active; and an extinct volcano has died out volcanically and won't ever erupt again. Active volcanoes endanger plant and animal life, but lava and ash add enriching minerals to the soil. There are three types of volcanic mountains: -Shield volcanoes are the largest volcanic mountains because of a repeated, viscous lava flow from small eruptions over a long period of time that cause the mountain to grow. -Cinder cone volcanoes, or linear volcanoes, are small in size, but have massive explosions through linear shafts that spread cinders and ash around the vent. This results in a cone-shaped hill. -Composite volcanoes get their name from the mix of lava and ash layers that build the mountain.

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 one 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 picture of the features of a wave, which includes crests, troughs, amplitude, and wavelength.

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. Superacids are those that are stronger than 100% 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 (H₃PO₄) is added to sodas and other acids are added to foods 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 hydroxides. 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.