PSB EXAM
______________ reaction- a reaction in which 2 or more simple substances react together to form a new complex substance. It is an endothermic reaction. For example, Na and Cl atom will join to form NaCl. Na + Cl → NaCl
Synthesis
___________________ is a process in which two liquids are separated from each other based on their boiling points. When a mixture of water and ethanol is heated, the ethanol evaporates at 78.73°C and is collected in a chamber. When the temperature rises to 100°C water also evaporates and is collected in a separate chamber. This process is also used in the purification of crude oil.
Fractional distillation
When molecules lose or gain electrons, they form _________________. When molecules gain electrons they form anionic molecules like SO4-2 and when molecules lose electrons, they form cationic molecules CH4+.
molecular ions
Ionic compounds conduct electricity when in ___________ form.
molten
Effectors are
muscles or glands that reverse the change and maintain homeostatic balance.
In covalent compounds atoms are joined by ____________________ for example in ammonia (NH3) one nitrogen atom shares three covalent bonds with three hydrogen atoms.
covalent bonds
The brainstem consists of
the midbrain, pons, and medulla oblongata
Radioactive decay normally emits three types of radiation:
alpha radiation (α-rays), beta radiation (β-rays), and gamma radiation (γ-rays).
Group 17 contains
halogens
_____________________ reaction- a reaction in which one element replaces another element in a compound and a new element is free. For example, Na metal and H2O reaction. 2Na + 2H2O → 2NaOH + H2
Single displacement
______________ are formed when a substance (solute) is dissolved in a liquid (solvent) to make a homogenized mixture. The amount of solute that is dissolvable in 100g of solvent at a fixed temperature is known as the solubility of the solute. The solubility increases with the increase of temperature. A solution that contains the maximum amount of a solute that is able to be dissolved at a fixed temperature is known as a saturated solution. The concentration of solutions is measured in g/dm3 or mol/dm3.
Solutions
Hydrogen is the most abundant element in the universe. It is present in the form of diatomic gas and is an important constituent of organic compounds. It is the __________ member of the periodic table and is nonmetallic in nature. It releases one electron and forms an H+1 ion. It forms both ionic and covalent compounds. The most important compound of hydrogen is __________, essential for life (in Greek, hydrogen means "water-former").
first, water
Class is
formed by combinations of orders. For example, Aves contain all types of birds, there are 108 different classes in animals.
The emission of a helium atom's nucleus during nuclear breakdown results in what kind of emission?
gamma ray emission
Radioactive elements decay to attain a stable atomic form. The time taken by half of the radioactive atom to decay is known as
half-life
A sensor or receptor detects changes in
homeostatic balance and reports the change via stimulus or signal to the control center.
Polymers: For example, when a lot of ethene molecules join they form polyethene, also known as polythene. Polymers are very interesting to understand as they can act as insulators for electricity and heat, are lightweight, and are waterproof. In living organisms, the best example of polymers are proteins. Polymers can be ______________ (consist of the same type of molecules) or ______________ (contain different types of molecules). Polymers can be classified based on their structure or source of availability.
homomer, heteropolymer
99 % of the universe consists of ________________________. Living organisms are mainly formed of nonmetals, for example, carbon, oxygen, hydrogen, nitrogen, sulfur, and phosphorus.
hydrogen and helium
Group 1 of the periodic table consists of Groups 13-16 each contain at least one metalloid. ... Group 17 contains halogens. ... Group 18 consists of noble gases.
hydrogen and the alkali metals.
Water is a colorless liquid that is composed of two hydrogen atoms that are covalently bound to an oxygen atom (H2O). The molecules of water have an extra intermolecular force of attraction known as _________________ bonding which gives it high melting and boiling points. From a chemical perspective, water is a natural _____________ compound. _____________ compounds are those compounds which can act both like acid and base.
hydrogen, amphoteric, Amphoteric
Liquids have no defined shape and take the shape of the container. Atoms have a force of attraction but not as strong as in solids. Atoms can randomly move in liquid form and have high _________ energy. Liquids have fixed volume but no fixed shapes
kinetic
The homeostatic balance works on a feedback system that involves
sensors, a control center, and effectors.
The first vaccine was developed against which disease?
smallpox
On the basis of ____________, polymers can be linear polymers (a straight chain), branched-chain, or crosslinked polymers. On the basis of _______________, polymers can be classified as natural (starch), seminatural (cellulose nitrate), or synthetic (nylon). As the chain length of polymers increases, their strength also increases.
structure, availability
The freezing and melting points of water are 0°C and the boiling point is 100°C. Sometimes solids directly convert into gas instead of going through the liquid process is known as _______________. The opposite process is known as _____________.
sublimation, deposition
Your diastolic blood pressure is the bottom number on your reading. It measures...
the force of blood against your artery walls as your heart relaxes and the ventricles are allowed to refill with blood. Diastole — this period of time when your heart relaxes between beats — is also the time that your coronary artery is able to supply blood to your heart.
Your systolic blood pressure is the top number on your reading. It measures...
the force of blood against your artery walls while your ventricles — the lower two chambers of your heart — squeeze, pushing blood out to the rest of your body.
Lithosphere is
the outermost layer of earth which consists of the earth's crust and upper mantle (layer below the crust). It is subdivided into tectonic plates that move over thousands of years.
Group 18 consists of
noble gasses
Molecules are formed when _____________________. Molecules are considered the smallest independent entity of pure substance.
one or more atoms join together.
A process in which an atom/molecule loses electrons is known as _____________. A process in which an atom/molecule gains electrons is known as ______________. A reaction in which oxidation and reduction is occurring simultaneously is known as _______________.
oxidation, reduction, Redox reaction
Hemoglobin is responsible for distributing
oxygen, and to a lesser extent, carbon dioxide, throughout the circulatory systems of humans, vertebrates, and many invertebrates. The blood is more than the proteins, though
Increased use of chemicals releases chlorine and bromine in the ozone layer which strips the oxygen-free from the ozone layer, a process known as __________________. Ozone depletion has created holes in the ozone layer which is increasing global warming on earth and disturbing the Earth's ecosystems.
ozone depletion
The method to find out how much acid and base is required to neutralize each other is known as _____________. An indicator is used to see the endpoint of a reaction. _____________ are substances which change color with the change of pH.
titration, Indicators
Groups 3-12 contain
transition metals
Radioactive decay was first reported by a French scientist Henri Becquerel in 1896, when he reported emission of radiation from Uranium atoms. His student, Mary Curie discovered that only some elements emit radiation and she named this phenomenon...
radioactivity.
Coulomb (C) used for
charge (=As)
Nerve endings are present in the following layer of skin:
hypodermis
Ions
charged particles that are formed when an atom loses or gains electrons.
1 kg = ___ lbs
2.2 lbs
1 ton = ____ pounds
2000 lbs
Lipids are the storage unit of living organisms. Lipids are important for the formation of membranes and constitute carbon, oxygen, and hydrogen. Carbon is the ______th most abundant element of the universe and due to its unique chemical properties, it is known as the central element of life.
4th
Reactions are divided into ____ categories based on chemical properties, synthesis, decomposition, single displacement, double displacement, redox, and combustion.
6
Archaebacteria
Archaebacteria are the oldest known living organisms and the most recent addition to the kingdoms of organisms in the 1980s. They are single-celled and thrive in extreme environments like hot boiling water springs or in very salty environments such as The Great Salt Lake. Their cells have no membrane-bound organelles. Archaebacteria have the following characteristics: Extremophiles: live in extreme environments. Genetic material: circular DNA or smaller circular molecules of DNA called plasmids. Ribosomes: (70 S) are smaller than in eukaryotic cells. Cell wall: does not contain peptidoglycans. Cells divide by binary fission, not by mitosis and have no spores. Usually exist as single cells or small groups of cells.
The_______________ is the continuous movement of Carbon in the earth's biosphere and atmosphere. Carbon is a component of all major biological molecules. Carbohydrates, lipids, proteins, DNA, vitamins, and many other molecules all contain carbon.
Carbon Cycle
___________ is a member of group IV (4) in the periodic table. ___________ has 4 electrons in the outermost shell and forms usually four stable covalent bonds with other elements. It can make a vast number of variable compounds. _____________ can make large macromolecules or polymers. In living organisms __________ forms carbohydrates, proteins, nucleic acids, and lipids.
Carbon, Carbon, Carbon, Carbon
_______________ reaction- a reaction in which a compound is burned in the presence of oxygen. Combustion reactions are also exothermic reactions. For example, the burning of methane gas. CH4 + O2 → CO2 + 2H2
Combustion
__________________________ reaction- a reaction in which elements from two compounds replace each other and new compounds are formed. For example, Sodium iodide and Silver nitrate reaction. NaI + AgNO3 → NaNO3 + AgI
Double displacement
Protons have a relative mass of 1 and contain a charge of +1 (positive charge).
Ernest Rutherford discovered protons in 1917. The number of protons in an atom is known as the atomic number of the atom.
_________ bonding is a strong electrostatic force of attraction between charged ions. One element loses an electron (cation) and the other element gains an electron (anions). This is the second strongest type of bonding. For example, in NaCl (Sodium Chloride) Na loses one electron and forms Na+1 ion and Cl gains one electron and forms Cl-1 ion and they are held together by the electrostatic force of attraction and form NaCl. Ionic compounds conduct electricity in molten form.
Ionic
________________ bonding is also a type of electrostatic force of attraction. When atoms of metal join together, the outer shell electrons freely move in the structure and metal atoms become positively charged ions. These delocalized electrons are attracted to positive nuclei by the electrostatic force of attraction to create metallic bonding. For example, in a magnesium metal, two electrons from the outermost shell move freely in the metallic lattice and the magnesium atom becomes a positively charged ion (Mg2+). These Mg2+ ions attract the freely moving electrons. Metallic bonding is only present in metals and delocalized electrons are the reason that metals are good conductors of electricity.
Metallic
________________ are elements that show both metallic and nonmetallic properties. Metalloids have ionization energy between that of metals and nonmetals. ______________ are semiconductors and have variable properties like conductivity, hardness, melting point, and boiling point. For example, silicon is a shiny solid, like metals but does not conduct electricity. Silicon is the second most abundant element on earth's crust. The smallest percentage of metalloids is present in living organisms.
Metalloids, Metalloids
______________ and ______________ sometimes are also defined on the basis of the transfer of oxygen. When a substance loses oxygen, it is reduced and when a substance gains oxygen it is oxidized.
Oxidation, reduction
The nucleus of an atom is composed of
PROTNOS AND NEUTRONS while electrons revolve around the nucleus. A nucleus is positively charged and all the mass of the atom is localized in the nucleus because the mass of electrons is negligible. Protons and neutrons are also known as nucleons due to their presence in the nucleus.
The number of __________ determines an element's atomic number (Z) and distinguishes one element from another.
PROTONS... For example, carbon's atomic number (Z) is 6 because it has 6 protons.
_______________________ is used to separate different colored compounds in a mixture via chromatogram. One good example is the separation of colored dyes. A mixture is added on a filter paper and put in a solvent. The solvent travels through the paper and the dyes also travel with it. Each dye travels based on its density. Less dense dyes will travel faster as compared to the denser dyes and therefore they are separated from each other.
Paper chromatography
How much stronger is a pH of 4 than a PH of 6?
The pH scale is logarithmic and as a result, each whole pH value below 7 is ten times more acidic than the next higher value. For example, pH 4 is ten times more acidic than pH 5 and 100 times (10 times 10) more acidic than pH 6.
Electrons constantly move around the nucleus in a region of space called orbits or shells. Electrons were discovered by J.J. Thompson in 1897.
The relative mass of an electron is 1/1836 of the mass of a proton and its charge is -1 (negative charge). The number of protons is equal to the number of electrons in a neutral atom. The arrangement of electrons in shells around the nucleus is known as electronic configuration. The number of electrons in each energy level is fixed.
A nerve is
an enclosed bundle of nerve fibers called axons and is the basic unit of the peripheral nervous system.
Endothermic reactions absorb heat from the surroundings, this heat energy is used to make new bonds. Endothermic reactions are also known as ____________ reactions. Exothermic reactions are those reactions that release heat in the environment. Heat is released when chemical bonds are broken. Exothermic reactions are also known as _______________ reactions. Chemical reactions are normally shown by symbolic balanced chemical equations. Reactant 1 + Reactant 2 → Product 1 + Product 2
anabolic, catabolic
Nitrogen is a member of group V (5). It is abundantly present in the form of diatomic gas in the earth's atmosphere. Nitrogen mainly forms covalent bonds and is an essential part of biomolecules, such as DNA and proteins. Nitrogen is a central member of amino acids which are building blocks of proteins and is fixed via plant-microbe interaction. Nitrogen-fixing bacteria live in the roots of plants (for example legumes) and fix free nitrogen into nitrogenous ions like ammonium ions (NH4+1). When living organisms die, ___________ in soil decompose the nitrogen from dead organisms.
bacteria
In 1869 Dimitri Mendeleev started to arrange elements in a table according to their mass number to make a periodic table of elements. In the modern periodic table, elements are arranged by _______________________________
increasing atomic number.
In solids, atoms are closely packed and form a shape. Atoms of solids are bound by a strong force of attraction. The atoms have less __________ energy and they cannot move around, they can only vibrate in a fixed position. Solids have fixed volumes and shapes.
kinetic
The ________________ is similar to the carbon cycle, it is a biogeochemical process in which nitrogen passes from the atmosphere to the biosphere of an ecosystem and then back to the atmosphere. Nitrogen as an element is present in many biological compounds including proteins, amino acids, most vitamins, DNA, and ATP.
nitrogen cycle
In translation, adaptor molecules that carry the amino acid in a ribosome and read the codon are called
tRNA
The solar system consists of
the sun and gravitationally bound objects that orbit around it. The solar system is 4.6 billion years old. Most of the mass of the solar system is in the sun and then planet Jupiter. Mercury, Venus, Earth, and Mars, are terrestrial planets, being primarily composed of rock and metal. The two largest planets, Jupiter and Saturn, are gas giants, being composed mainly of hydrogen and helium. The two outermost planets, with the sun being in the center of the orbit, are Uranus and Neptune, they are both ice giants. Earth is the only habitable planet in the solar system and all life forms on earth depend on the sun. Without the Sun's heat and light, Earth would be a lifeless ball of ice-coated rock. The Sun generates our weather patterns and gives energy to the growing plants that provide the food and oxygen for life on Earth.
What is strongest kind of bonding?
Covalent bonding
Newton (N) used for
force (= kgms-2)
Radioactive isotopes/radioisotope are
unstable isotopes which release an enormous amount of energy in the form of radiation.
Vessels that carry blood toward the heart are....
veins
In the gas phase, atoms move more randomly and have no force of attraction. The kinetic energy in gas molecules is very high. Gases do not have a fixed ___________ or shape.
volume
The pH scale is numbered _____________. A neutral solution has a pH of 7.0, where an acidic solution has a pH between 1-7, and a basic solution has a pH between 7-14. The acidity of an acid is the tendency of compounds to release H+ ions in a solution. The basicity of a base is the tendency of the base to release OH ions in solutions. Acids and bases react to form salt and water, this process is known as neutralization process. Acid releases H+ ions and base releases OH-1 ions which join to form water molecules. An example reaction is between Copper oxide and Sulfuric acid
1 to 14
1 kilometer (km) =
1,000 m
3 layers of geosphere
1. Earth's crust is the uppermost layer which is 1% of earth volume. Earth's crust is often confused with the lithosphere. The crust comprises several elements that can vary in percentage in different areas but majorly it is as follows: 46.6% oxygen, 27.7% silicon, 8.1% aluminum, 5% iron, 3.6% calcium, 2.8% sodium, 2.6% potassium, and 2.1% magnesium. Earth's crust is further divided into oceanic crusts (5 to 10 km thick) and continental crusts (30 to 50 km thick). 2. Mantle is the solid bulk of the Earth's interior which comprises 67% of earth's total volume. The mantle lies below the earth's thin crust. The mantle is about 2,900 kilometers thick. Silicon, magnesium, and iron dominate the composition of the mantle. It varies from a solid-state (near crust) to a molten state (near core) due to temperature differences. 3. Core is the innermost layer of the geosphere. It is divided into two parts, the outer core, and inner core. The outer core is molten and mainly composed of iron and nickel and its thickness is between 2800 to 5000 km. The inner core is solid and mainly consists of iron and a small amount of nickel and gold. The Inner core moves from north to south and is responsible for the creation of the earth's magnetic field. The temperature of the inner core is 5700 K (close to the temperature of the sun) and the thickness is 5000-6000 km.
A chemical reaction is a process in which one substance is converted chemically into another substance. The two types of chemical reactions are based on their energy requirements 1. _____________ 2. _____________
1. Endothermic 2. Exothermic.
The nitrogen cycle has the following stages:
1. Nitrogen fixation is a process by which nitrogen-fixing bacteria in root nodules found in the soil convert nitrogen gas into ammonia. 2. Nitrification is a process by which ammonia is converted into nitrites (NO2-) and then into nitrates (NO3-) which are used by the plants to make amino acids and proteins, however, side by side denitrifying bacteria in soil converts nitrogen back into gaseous form. 3. When fungi and bacteria go through the process of decomposition, ammonia is produced from the nitrogen-containing organic compounds like proteins, DNA, and vitamins. The death and decomposition of plants return the nitrogen to the soil as ammonia.
1 nanometer (nm) =
1/1,000,000,000 m
1 micrometer (µm) =
1/1,000,000m
1 decimeter (dm) = ___ m
1/10 meter= 0.1 m
1 centimeter (cm) =
1/100 meter = 0.01 m
1 millimeter (mm) =
1/1000m
The mass of an electron is negligible. As a fraction of the mass of a proton, it is around:
1/1836
Water is an excellent solvent thus responsible for most chemical reactions in living organisms. Pure water has pH of _____. The existence of life requires water, living organisms are 90% water by body mass. Water has unique properties that are not exhibited by other compounds. All the chemical reactions in living bodies occur in the presence of water. Hydrogen bonding in water provides cohesion and adhesion properties to water molecules.
7
One atmosphere of pressure is equivalent to
760 mm Hg (millimetre of mercury)
Types of Ions: if an atom gains an electron and becomes negatively charged it is known as an
ANION... For example, a chlorine atom gains one electron and becomes negatively charged chloride ion Cl-1.
___________ are substances that release H+ ions in a solution. For example, when HCl is mixed into a solution it forms H+ and Cl- ions. __________ are substances that release OH ions in a solution. NaOH when dissolved in water forms Na+ and OH-1 ions. The idea of acids and bases is centuries old. In 1883 Svante Arrhenius first defined the above-mentioned definitions of acids and base. In 1909 the pH scale was developed to measures the strength of acids and bases.
Acids, Base or alkalis
ATP
Adenosine triphosphate is an organic compound and hydrotrope that provides energy to drive many processes in living cells, such as muscle contraction, nerve impulse propagation, condensate dissolution, and chemical synthesis. Found in all known forms of life, ATP is often referred to as the "molecular unit of currency" of intracellular energy transfer.
In which organs is food moved through by peristalsis?
After food is swallowed, it is moved down the esophagus by peristalsis. The muscles in the stomach, small intestine, and large intestine continue the process.
Electricity: Current (I) = Charge (Q) / time (t) .....or....
Ampere = Coulombs/ seconds
Types of Ions: When an atom loses electrons, it becomes positively charged and known as a
CATION... For example, a sodium atom loses an electron and becomes Na+1.
Phylum is formed by the combination of
Classes. For example, Phylum Chordata contains all classes of animals with a backbone. There are 35 animal phyla.
_____________ is an attraction between water molecules that make water droplets. _____________ is an attraction between water molecules and non-watery surfaces like glass. Hydrogen bonding also provides spaces between water molecules when it freezes to form ice. That is the reason ice is light in weight and water expands when it forms ice. The freezing and melting point of water is 0°C and the boiling point is 100°C.
Cohesion, Adhesion
Photosynthesis is a process that fixes the carbon from air (carbon dioxide) in organic compounds in the presence of sunlight. The food chain passes the carbon compound from plants to various consumers in an ecosystem known as carbon assimilation, or fixation. Respiration is a process in which organic compounds are broken down into inorganic carbon dioxide to release energy....
Combustion is a process in which carbon dioxide is released into the atmosphere from the burning of fuels. Fossilization is a process in which carbon-containing compounds of living organisms do not decay fully when they die due to the conditions in the soil, therefore fossil fuels are formed.
There are two main types of compounds 1. ____________ compounds and 2. _________ compounds.
Covalent, Ionic
CHEM: ______________bonding is a type of bonding in which one or more pairs of electrons are shared between the atoms. ________________ bonding creates stability in compounds, and they are difficult to break. For example, in a diamond, carbon atoms share 4 electrons with other carbon atoms which create such a strong bond that gives diamonds extremely high melting and boiling point. They do not conduct electricity in solid or molten form.
Covalent, covalent
_______________ is a process used to separate a crystal-forming solute from water. Water evaporates and crystals of the solute remain. An example is the separation of sodium chloride from sodium chloride solution.
Crystallization
______________ reaction- a reaction in which a complex compound breaks down and makes simple compounds. It is an exothermic reaction and the opposite of a synthesis reaction. For example, H2O breaks down. 2H2O → 2H2 + O2
Decomposition
________________ is a process in which evaporation and condensation is used to separate components of a solution. For example, when a solvent is evaporated by heating, it is collected in a glass tube, so it condenses back into liquid and collected separately.
Distillation
Radioactive decay was first reported by a French scientist ___________ in 1896, when he reported emission of radiation from Uranium atoms. His student, ___________ discovered that only some elements emit radiation and she named this phenomenon as radioactivity.
Henri Becquerel, Mary Curie
Eubacteria are
Eubacteria are single-celled, common, and well-known bacterial organisms. This kingdom makes up most of the parasites like Streptococci which causes throat infection. However, these bacteria also have useful aspects as they help in the production of many antibiotics, vitamins, and yogurt. Eubacteria have the following characteristics: Nucleus: cells with no nucleus. Organelles: no membrane-bound organelles (such as mitochondria) are present. Ribosomes: smaller than in eukaryotic cells. Cell wall: contains peptidoglycans (not cellulose). Cells division: binary fission, spore formation.
The periodic table has groups and periods. ___________ are vertical columns that are named from I (1) to VIII (8, also known as group 0). The number of the __________ represents the number of outermost shell electrons of the elements. For example, all elements in group I have one electron in their outermost shell while elements in group VII (7) have seven electrons in the outermost shell. _____________ are horizontal rows. The ___________ number shows the number of occupied shells of an element for example sodium (11Na) is in the third period and has an electronic configuration of 2,8,1. This means three shells are occupied.
Groups, group, Periods, period
Neutrons are also present in the nucleus, have a mass of 1, and are neutral (not positively or negatively charged). Neutrons were discovered by
James Chadwick in the year 1932. The total number of protons and neutrons is known as mass number or nucleon number.
All other units are derived from these basic and supplementary units and are known as derived units, for example, the SI unit of force is Newton (N) which is equal to kgms-2. It is derived from mass, length and time. The most common derived units are:
Joules (J) used for energy (= kgm2s-2), Watt (W) used for power (= kgm2s-3) Coulomb (C) used for charge (=As) Newton (N) used for force (= kgms-2)
Molecules can have similar or different atoms. The size of molecules varies and depends upon the number of atoms and their size. Large molecules are known as ________________ like Carbohydrates, DNA, and Hemoglobin.
Macromolecules
What are the four classes of macromolecules?
Macromolecules that constitute all living matter: carbohydrates, lipids, proteins, and nucleic acids.They are all composed of long complex chains of molecules (polymers) made up of simpler, smaller subunits (monomers).
____________ are formed when 2 or more substances are mixed together without any chemical reaction. Components of mixtures retain their individual properties. One good example of a naturally occurring mixture is crude oil which has different organic compounds mixed together. The separation of mixtures can be done by different methods such as filtration, crystallization, distillation, fractional distillation, and paper chromatography.
Mixtures
_______________ formulas show the actual number of atoms in a molecule. For example, the glucose molecule has C6H12O6 as its ______________ formula. The simplest ratio of atoms in a molecule is known as an _______________ formula, for example, the empirical formula of glucose is CH2O.
Molecular, molecular, empirical
The functional unit of the kidney is the...
NEPHRON and it is called the functional unit because its the smallest structure in the kidney that can carry out its functions.
Kingdom is the major category of classifications. There are six known kingdoms:
Prokaryotes Eubacteria, Archaebacteria, Protista, Animalia, Plantae, and Fungi.
Protista or Protozoa
Protista or Protozoa are single-celled organisms. They are more complex than single-celled bacteria. This kingdom includes algae and slime molds. Any microscopic organism that does not fall into the bacterial, fungi, plant, or animal kingdoms is considered a part of the Protista kingdom. Protista have the following characteristics: Nucleus: have nucleus, eukaryotic. Some have animal-like cells (no cell wall) and are sometimes known as protozoa. Others have plant-like cells (with cellulose cell walls and chloroplasts) and are sometimes known as algae.
Vertebrates have two kinds of photoreceptor cells, called
RODS AND CONES because of their distinctive shapes. Cones function in bright light and are responsible for color vision, whereas rods function in dim light but do not perceive color. A human retina contains about 3 million cones and 100 million rods.
______________ reaction- a reaction in which electrons are transferred from an atom/molecule to another for example Zinc chloride electrolysis Zn+2 + 2e- → Zn (reduction) 2C1-1 → Cl2 + 2e- (oxidation)
Redox
Relative atomic mass
Relative atomic mass = (mass of isotope X abundance of the isotope in nature) + (mass of isotope X abundance of the isotope in nature)/ 100 For example, lithium has two isotopes Li-6 (abundance 7 %) and Li-7 (abundance 93 %). In order to calculate the relative atomic mass Relative atomic mass= (6×7) + (7×93) /100 Relative atomic mass = (42 + 651) /100 Relative atomic mass = 693/100 Relative atomic mass = 6.93 Relative atomic mass also gives the idea that which isotope is more abundant in nature. For example, in the above example, the relative atomic mass is 6.93 which is closer to 7, so Li-7 is more abundant in nature.
Boron has 2 isotopes B-10 which has 20% abundance and B-11 which has 80% abundance. Its relative atomic mass is:
Relative atomic mass= (20×10) + (11×80) /100 Relative atomic mass = 200 + 880 /100 Relative atomic mass = 1080/100 Relative atomic mass = 10.8
meter (unit of length), kilogram (unit of mass), second (unit of time), kelvin (unit of temperature), ampere (unit of current), candela (unit of luminous intensity), and the mole (unit of substance amount).
SI Units
The largest kingdom of organisms is made up of complex, multi-celled organisms. All organisms in the animal kingdom are heterotrophs meaning, animals feed upon other organisms.
The animal kingdom has over one million known species. Animals have the following characteristics: Multicellular eukaryotes Cells do not have chloroplasts or cell wall Cell vacuoles are small and temporary (for example, lysosomes and food vacuoles) Heterotrophic nutrition Tissues and organs
thymus gland function
The thymus is a specialized primary lymphoid organ of the immune system. Within the thymus, thymus cell lymphocytes or T cells mature. T cells are critical to the adaptive immune system, where the body adapts specifically to foreign invaders. The thymus is located in the upper front part of the chest, in the anterior superior mediastinum, behind the sternum, and in front of the heart. It is made up of two lobes, each consisting of a central medulla and an outer cortex, surrounded by a capsule.
Chemical bonding: (chemistry) Covalent bonding is
a type of bonding in which one or more pairs of electrons are shared between the atoms. Covalent bonding creates stability in compounds, and they are difficult to break. For example, in a diamond, carbon atoms share 4 electrons with other carbon atoms which create such a strong bond that gives diamonds extremely high melting and boiling point. They do not conduct electricity in solid or molten form.
______________________ forces are distance related intermolecular electrostatic forces. There are three types of Van der Waal forces A. dipole-dipole interaction B. dispersion forces C. hydrogen bonding. They are weaker than covalent and ionic bonding and act over a short-range. Hydrogen bonding is a special intermolecular force of attraction between hydrogen atoms and a nearby electronegative atom in liquids or solutions. For example, in water, a hydrogen atom of one water molecule is attracted by an oxygen atom of another water molecule.
Van der Waal
The Water cycle is also known as the hydrological cycle is the continuous movement of water in the earth's biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth
Water cycles involve the transfer of energy also such as when water evaporates the process is endothermic and the environment becomes cooler. When water condenses, the process is exothermic, it warms the surroundings.
Biosphere, also known as the ecosphere, is
a closed system that contains all life on earth. The biosphere is also defined as a global ecological system that deals with living organisms and their interaction with elements of the lithosphere, hydrosphere, and atmosphere. The term biosphere was first described in 1875 by geologist Eduard Suess, which he defined as the place on Earth's surface where life dwells. The oldest biological signature found in fossils is 3.7 billion years old.
Order is
a combination of similar families. For example, there are 12 carnivorous families in the order Carnivora.
Genus is
a group of similar species. One example is the Rosa genus which contains hundreds of rose flower species. Family is a combination of similar genera. For example, the genus of horses and zebras form a family.
The limbic system is
a set of structures in the brain that deal with emotions and memory. It regulates autonomic or endocrine function in response to emotional stimuli and also is involved in reinforcing behavior
The Punnett square
a square diagram that is used to predict the genotypes of a particular cross or breeding experiment. The diagram is used by biologists to determine the probability of an offspring having a particular genotype.
Chemical bonding: (chemistry) Ionic bonding is
a strong electrostatic force of attraction between charged ions. One element loses an electron (cation) and the other element gains an electron (anions). This is the second strongest type of bonding. For example, in NaCl (Sodium Chloride) Na loses one electron and forms Na+1 ion and Cl gains one electron and forms Cl-1 ion and they are held together by the electrostatic force of attraction and form NaCl. Ionic compounds conduct electricity in molten form.
Alcohols are organic compounds that contain -OH groups. The general formula is ROH where R is an alkyl group. Alcohols have covalent bonding as well as hydrogen bonding. Alcohols are soluble in water and form hydrogen bonding with water molecules too. Alcohols are __________(basic or acidic) in nature. Alcohols are highly flammable and good solvents of organic compounds. Alcohol undergoes a combustion reaction and forms water and carbon dioxide.
acidic
Group 2 consists of the
alkaline earth metals
Geosphere is
all the solid layers of earth, in contrast to the lithosphere which is the uppermost layer of earth layers. The geosphere has three main layers named Earth's crust, mantle, and core.
Hydrosphere is
all water forms on earth which include underground water, atmospheric vapors, and water on the surface of the Earth. It is 4 billion years old. Saltwater accounts for 97.5% of this amount, whereas freshwater accounts for only 2.5%. Of the freshwater, 68.9% is in the form of ice and permanent snow cover in the Arctic, the Antarctic, and mountain glaciers; 30.8% is in the form of fresh groundwater; and only 0.3% of the freshwater on Earth is in easily accessible lakes, reservoirs, and river systems.
Metallic bonding is
also a type of electrostatic force of attraction. When atoms of metal join together, the outer shell electrons freely move in the structure and metal atoms become positively charged ions. These delocalized electrons are attracted to positive nuclei by the electrostatic force of attraction to create metallic bonding. For example, in a magnesium metal, two electrons from the outermost shell move freely in the metallic lattice and the magnesium atom becomes a positively charged ion (Mg2+). These Mg2+ ions attract the freely moving electrons. Metallic bonding is only present in metals and delocalized electrons are the reason that metals are good conductors of electricity.
All the living things mainly consist of organic compounds that contain __________, ___________, ___________ and ______________. These elements are also known as abundant and essential elements of the universe.
carbon, oxygen, hydrogen and nitrogen
Proteins are made of ____________ that contain mainly ___________ and ___________. Proteins are the building blocks of living bodies. All enzymes are also proteins. Nucleic acid (DNA and RNA) contains carbon, hydrogen, oxygen, nitrogen, and phosphorus. Nucleic acids carry the genetic information of an organism.
amino acids, carbon and nitrogen
Taxonomy is the study of classification, which involves
arranging organisms in a series of groups or units known as taxa. In biological classification system all organisms are ranked as previous categories
Vessels that carry blood away from the heart are....
arteries
Groups 13-16 each contain
at least one metalloid.
In terms of ecology, the Earth is divided into the following regions:
atmosphere, hydrosphere, lithosphere, geosphere, and biosphere.
Isotopes are
atoms that have the same number of electrons and protons but vary in the number of neutrons.
The temperature at which liquid turns into gas is known as the ___________ point. The opposite process in which gas turns into liquid is known as ____________.
boiling, condensation
Isotopes were first described by the radiochemist Frederick Soddy. Example:
carbon has three naturally occurring isotopes carbon-12, carbon-13, and carbon-14. All three isotopes have 6 electrons, 6 protons but the number of neutrons is 6, 7, and 8 respectively. Isotopes can be radioactive or non-radioactive in nature.
Carbohydrates consist of mainly _________, _________, and __________ atoms. Carbohydrates are the main source of energy for living cells. The breakdown of carbohydrates in living cells releases energy which living organisms use for survival and other vital functions.
carbon, oxygen, and hydrogen
Compounds are different from mixtures. In mixtures, two or more substances are mixed together without any ____________________, for example-- an iron and sulfur mixture. In compounds, atoms lose their __________________ while in mixtures atoms do not. Atoms of a compound can only be separated by chemical means, while substances in a mixture can be separated by physical means like crystallization, fractional distillation, and chromatography.
chemical reaction, individual properties
When two or more different atoms join together chemically, they form ________________. The atoms are held together in a ______________ by the strong bonding forces.
compounds, compound
Species can be defined as
consisting of similar individuals capable of exchanging genes or interbreeding. For example, monkeys living in a habitat are species. There are 8.7 million different species of organisms on Earth.
The Plant or Plantae kingdom
consists of all types of plants, mosses, and ferns. Plants are multi-celled, complex organisms and are considered autotrophic. This means that plants create their own food through photosynthesis. The plant kingdom has over 25,000 known species. Plants have the following characteristics: Multicellular eukaryotes. Some cells have chloroplasts and photosynthesis. Cells have large vacuoles for support and cell walls are always present and are made of cellulose. Autotrophic nutrition. Tissues and organs.
The fungi kingdom
consists of mushrooms, molds, mildews, and yeasts. Unlike the organisms in the archaebacteria and eubacteria kingdoms, fungi are multi-celled organisms. Fungi have the following characteristics: Eukaryotic- simple body form Do not have chlorophyll and do not photosynthesis Reproduce by means of spores Cells have cell walls made of chitin or other substances, not cellulose Heterotrophic nutrition
The relaxation phase of the heartbeat is called the ____________, while the contraction phase of the cardiac cycle is called ____________
diastole... and systole
Van der Waal forces are
distance related intermolecular electrostatic forces. There are three types of Van der Waal forces A. dipole-dipole interaction B. dispersion forces C. hydrogen bonding. They are weaker than covalent and ionic bonding and act over a short-range. Hydrogen bonding is a special intermolecular force of attraction between hydrogen atoms and a nearby electronegative atom in liquids or solutions. For example, in water, a hydrogen atom of one water molecule is attracted by an oxygen atom of another water molecule.
Speed is the time rate at which an object is moving along a path, while velocity is the rate and direction of an object's movement. Put another way, speed is a scalar value, while velocity is a vector. ... In its simplest form, average velocity is calculated by
dividing change in position (Δr) by change in time (Δt).
the lithosphere has tectonic plates that are made from the earth's crust and mantle. There are two types of tectonic plates, oceanic plates and continental plates. The oceanic plates usually have basaltic or silicate rocks while continental plates have low-density granite rocks. The oceanic plates range in thickness from 5-10 km in deep oceans to over 70 km beneath large mountain ranges. The tectonic plates move very slowly, approximately a few centimeters per year. When two plates slide past each other...
earthquakes are generated. These earthquakes are stronger than the earthquakes generated in the center of plates. Earthquakes shake the ground and powerful earthquakes can crack the earth crust.
The Control center compares and analyses the value to normal range and sends signals to the
effector
Hydrogen bonding is a special intermolecular force of attraction between hydrogen atoms and nearby __________________ atoms in liquids or solutions.
electronegative
The arrangement of electrons in shells around the nucleus is known as
electronic configuration
In ionic compounds, ions are held together by the _____________________________________ for example in sodium chloride Na+ and Cl- ions are attracted by the electrostatic force of attraction of opposite charges.
electrostatic force of attraction
Joules (J) used for
energy (= kgm2s-2)
The structure that keeps food from entering the larynx is the
epiglottis
Sometimes liquid molecules without heating gain enough energy to escape from the liquid surface; this process is known as _________________. _________________ occurs at all temperatures, only the rate of evaporation is different at each temperature.
evaporation, evaporation
Atmosphere is defined as
layers of gases that surround the earth and are under the influence of gravity. It contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases. The atmosphere protects the Earth from ultraviolet rays and extreme temperatures. Approximately 15-35 km above the earth's surface is the ozone layer also known as Ozonosphere. 90% of ozone is present in the region extending 10-18 km above the Earth's crust. The ozone layer is very important for life on earth. It absorbs extreme solar radiation from the sun, specifically ultraviolet rays which can kill living organisms. Photodissociation is the process in which high energy photons release the single oxygen atoms, which later join with intact oxygen molecules to form ozone. The ozone layer is responsible for the transfer of life from the ocean to land during evolution, by absorbing the ultraviolet rays.
Which blood component is responsible for antibody production?
lymphocytes
The total number of protons and neutrons is known as
mass number or nucleon number.
When chemical bonding between atoms of a compound is strong, more energy is required to break the bonds, therefore __________ and _________ points will be high.
melting and boiling
States of matter are interconvertible, they can change from one state to another, but require different temperatures for that. When solid atoms are heated, they gain energy and overcome the strong force of attraction between them they start to melt and form liquids. The temperature at which a solid turns into a liquid is known as the _______________. An opposite process in which liquids turn into solid is known as freezing where the temperature is known as the ____________________.
melting point, freezing point
Ionic bonds form between a ________________________________. Covalent bonds form between ___________________________.
metal and a nonmetal, two nonmetals
Schwann cells make
myelin in the peripheral nervous system (PNS: nerves) and oligodendrocytes in the central nervous system (CNS: brain and spinal cord).
Oxygen is essential for survival of living organisms. It is the most abundant element in living organisms and the 3rd most abundant element of the universe. Oxygen is nonmetallic gas and a member of group VI (6) and has six electrons in the outermost shell. Oxygen is highly electronegative, and it gains two electrons to form an O-2 ion. Oxygen is an important constituent of organic compounds. Oxygen is usually present in nature as a diatomic gas (O2), and is important for survival of living organisms. Oxygen is generated during ____________________ which is then inhaled by animals and plays a role in energy production, respiration and metabolic reactions. It also exists as Ozone in the upper atmosphere.
photosynthesis
This gland is sometimes called the master gland, though it is only about the size of a pea.
pituitary
Polymers that can be shaped and molded by using heat are known as __________ polymers. ____________ have low density, are transparent, and non-conductors. These properties make them very useful in different industries. Polyethylene, polystyrene, polypropylene, polyvinyl chloride, and Teflon are common types of synthetic plastics used in the preparation of plastic bags, Styrofoam, plastic bottles, food wrap, and non-stick surfaces respectively. One interesting example of polypropylene is Nylon which is a synthetic fiber. It is a strong wrinkle-resistant material.
plastic, Plastics
When small molecules join to make macromolecules, the process is known as ___________________ and resulting compounds are known as ________________
polymerization, polymers
Watt (W) used for
power (= kgm2s-3)
Alcohols can be ________, _________, or __________ alcohol. In primary alcohol, a carbon, containing an OH group, is not bound to any other carbon atom. For example, in methanol (CH3-OH) a carbon atom is bound to an OH group as well as three other hydrogen atoms. In secondary alcohol, a carbon containing an OH group is bound to one other carbon atom like in (CH3)2CH-OH. In tertiary alcohol a carbon-containing an OH group is bound to two other carbon atoms like in (CH3)3C-OH.
primary, secondary or tertiary
The periodic table is a good method for the classification of elements based on their ______________. Group I elements are known as ________________, they form ionic compounds and when they react with water they form hydroxide. They are highly reactive metals and form +1 charged ions. Group II members are known as__________________ and they are also reactive in nature. They lose two electrons to form +2 charged ions. They are very abundant in the earth's crust.
properties, Alkali metals, Alkaline earth metals
The half-life phenomenon is used to determine the approximate age of an object, a process known as _________________. For example, in order to determine the age of ancient organic material archeologists use carbon (C-14) dating. C-14 is an isotope of carbon. C-12 and C-14 are in a balanced ratio in living organisms however, when an organism dies, C-12 remains stable, and C-14 decays with a half-life of 5730 years. The ratio of C-14 and C-12 tells ________________________.
radioactive dating, the age of the organism
A radioisotope has an unstable nucleus and it breaks down to attain a stable form. This breakdown of the nucleus and emission of radiation is known as
radioactive decay. Radioactive decay normally emits 3 types of radiation: alpha radiation (α-rays), beta radiation (β-rays), and gamma radiation (γ-rays).