AP Bio – Midterm Study Guide

Natural Selection
Process by which individuals that are better suited to their environment survive and reproduce most successfully; also called survival of the fittest
Considered the ‘father of uniformitarianism’ – belief that the earth was old, and catastrophism happened slowly
Population Genetics
The study of genetic changes in populations; the science of microevolutionary changes in populations.
Sexual Recombination
New organisms are created from a relatively small number of alleles, result of sexual reproduction
Americn geneticist who succeeded in transferring a functioning gene from one mouse to another (born in 1934)
Reproductive Isolation
Separation of species or populations so that they cannot interbreed and produce fertile offspring
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Practice of classifying plants and animals according to their presumed natural relationships
Artificial Selection
Selection by humans for breeding of useful traits from the natural variation among different organisms
Modern Synthesis
A comprehensive theory of evolution that incorporates genetics and includes most of Darwin’s ideas, focusing on populations as the fundamental units of evolution.
Genetic Drift
The gradual changes in gene frequencies in a population due to random events
Ability of an organism to survive and reproduce in its environment
Prezygotic Barriers
A reproductive barrier that impedes mating between species or hinders fertilization if interspecific mating is attempted
The perserved trace, imprint, or remains of a plant or animal
Binomial Nomenclature
Classification system in which each species is assigned a two-part scientific name
the act of populating (causing to live in a place)
Bottleneck Effect
Genetic drift resulting from the reduction of a population, typically by a natural disaster, such that the surviving population is no longer genetically representative of the original population.
Directional Selection
Form of natural selection in which the entire curve moves; occurs when individuals at one end of a distribution curve have higher fitness than individuals in the middle or at the other end of the curve
Post-zygotic Barriers
reduced hybrid viability: offspring’s development is impaired. reduced hybrid fertility: offspring is sterile. hybrid breakdown: 2nd generation hybrids are not viable and/or fertile
Sedimentary Rocks
Rocks formed from the weathering, erosion, depostion, and compaction of other rocks
the quality of being similar or corresponding in position or value or structure or function
Hardy-Weinbery Equilibrium
1. evolution does not occur, because allelic frequencies never change
2. genotypic frequencies can be predicted from allelic frequencies
Founder Effect
change in allele frequencies as a result of the migration of a small subgroup of a population
Stabilizing Selection
form of natural selection by which the center of the curve remains in its current position; occurs when individuals near the center of a distribution curve have higher fitness than individuals at either end
Allopatric Speciation
The formation of a new species as a result of an ancestral population’s becoming isolated by a geographic barrier.
Lamark’s Theory
Hypothesized that species evolve through use and disuse of body parts and the inheritance of acquired characteristics. Unsupported
Vestigial Organs
organ that serves no useful function in an organism
Gene Pool
combined genetic information of all the members of a particular population
Gene Flow
exchange of genes between populations
Disruptive Selection
form of natural selection in which a single curve splits into two; occurs when individuals at the upper and lower ends of a distribution curve have higher fitness than individuals near the middle
Sympathetic Speciation
Occurs when species evolves into a new species in an area without a geographic barrier.
The theory that evolution occurs slowly but steadily
Molecular Homologies
homology of the genes and DNA between species due to a common ancestor
changes in the genetic material
Phenotypic Polymorphism
The existence of two or more distinct morphs (discrete forms), each represented in a population in high enough frequencies to be readily noticeable
Heterozygote Advantage
Greater reproductive success of heterozygous individuals compared to homozygotes; tends to preserve variation in gene pools.
Adaptive Radiation
the development of many different forms from an originally homogeneous group of organisms as they fill different ecological niches
the earth science that studies fossil organisms and related remains
dealing with the geographical distribution of animals and plants
Point Mutations
gene mutations involving changes in one or a few nucleotides
Genetic Polymorphism
The existence of two or more distinct alleles at a given locus in a population’s gene pool.
Sexual Selection
A form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates.
evolution on a large scale extending over geologic era and resulting in the formation of new taxonomic groups
a principle that states that geologic change occurs suddenly
evolution resulting from small specific genetic changes that can lead to a new subspecies
Gene Duplication
a mutation leading to the production of an extra copy of a gene locus, usually resulting from unequal crossing over. (source of new genes, allows new DNA to mutate and potentially gain new functions)
Geographic Variation
Differences between the gene pools of geographically separate populations or population subgroups.
Homeotic genes
Any of the genes that control the overall body plan of animals by controlling the developmental fate of groups of cells.
an enclosure of residences and other building (especially in the Orient)
Nonpolar Covalent Bonds
bonds in which electrons are shared equally between two atoms of the same element in a compound.
the elements or compounds that enter into a chemical reaction
Atomic Structure
The atom consists of three component parts: Protons, Neutrons, and Electrons.
Ion/Ionic Bond
an atom or groups of atoms having an electrical charge because of the loss or gain of electrons.
the elements or compounds produced by a chemical reaction
Atomic Mass
(chemistry) the mass (in atomic mass units) of an isotope of an element
Hydrogen Bond
a chemical bond consisting of a hydrogen atom between two electronegative atoms (e.g., oxygen or nitrogen) with one side be a covalent bond and the other being an ionic bond
negatively charged particles
Radioactive Isotope
isotope in which the nucleus decays (breaks down) over time, giving off radiation in the form of matter and energy
positively charged particles
Electron Energy
Strength of an attachment of an electron
the particles of the nucleus that have no charge
Potential Energy
the mechanical energy that a body has by virtue of its position
Atomic Number
the order of an element in Mendeleyev’s table of the elements
Electron Shells
An energy level representing the distance of an electron from the nucleus of an atom.
Polar Covalent Bonds
a type of covalent bond between atoms that differ in electronegativity. the shared electrons are pulled closer to the more electronegative atom. making one slightly negative and the other slightly positive
Valence Electrons
electrons on the outermost energy level of an atom
Functional Groups
A specific configuration of atoms commonly attached to the carbon skeletons of organic molecules and usually involved in chemical reactions.
The starches and sugars present in foods
energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen
Macromolecules that contain nitrogen as well as carbon, hydrogen, and oxygen
Nucleic Acids
an abundant nonmetallic tetravalent element occurring in three allotropic forms: amorphous carbon and graphite and diamond
the radical -NH2
a complex carbohydrate found chiefly in seeds, fruits, tubers, roots and stem pith of plants, notably in corn, potatoes, wheat, and rice
proteins that act as biological catalysts
Organic Chemistry
the chemistry of compounds containing carbon (originally defined as the chemistry of substances produced by living organisms but now extended to substances synthesized artificially)
one form in which body fuel is stored
something that causes an important event to happen
organic molecules that are composed of only carbon and hydrogen
carbonated drink with fruit syrup and a little phosphoric acid
a polysaccharide that is the chief constituent of all plant tissues and fibers
Structural Isomers
Compounds that have the same molecular formula but differ in the covalent arrangements of their atoms.
a nucleotide derived from adenosine that occurs in muscle tissue
a tough semitransparent horny substance
Amino acid
organic compounds containing an amino group and a carboxylic acid group
Geometric Isomers
Compounds that have the same molecular formula but differ in the spatial arrangements of their atoms.
a naturally occurring or synthetic compound consisting of large molecules made up of a linked series of repeated simple monomers
energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen
Peptide Bond
the primary linkage of all protein structures
molecules that are mirror images of each other
Dehydration Reaction
A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule.
Fatty Acid
any of a class of aliphatic monocarboxylic acids that form part of a lipid molecule and can be derived from fat by hydrolysis
single sugar molecules
Saturated fat
fat in which all three fatty acid chains contain the maximum possible number of hydrogen atoms
Primary structure
The level of protein structure referring to the specific sequence of amino acids.
the monovalent group -OH in such compounds as bases and some acids and alcohols
any of a variety of carbohydrates that yield two monosaccharide molecules on complete hydrolysis
Unsaturated fats
fats that remain liquid at room temperature
Secondary structure
The second level of protein structure; the regular local patterns of coils or folds of a polypeptide chain.
the univalent radical -COOH
Glycosidic linkage
A covalent bond formed between two monosaccharides by a dehydration reaction.
A molecule that is a constituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail.
Tertiary Structure
The third level of protein structure; the overall, three-dimensional shape of a polypeptide due to interactions of the R groups of the amino acids making up the chain.
a compound containing metal combined with carbon monoxide
an animal sterol that is normally synthesized by the liver
Quaternary Structure
The fourth level of protein structure; the shape resulting from the association of two or more polypeptide subunits.
Sickle Cell Disease
A human genetic disease caused by a recessive allele that results in the substitution of a single amino acid in the hemoglobin protein; characterized by deformed red blood cells that can lead to numerous symptoms.
loss of normal shape of a protein due to heat or other factor
(biochemistry) a long linear polymer found in the nucleus of a cell and formed from nucleotides and shaped like a double helix
(biochemistry) a long linear polymer of nucleotides found in the nucleus but mainly in the cytoplasm of a cell where it is associated with microsomes
a phosphoric ester of a nucleoside
adenine and guanine
T&C are _____, have only one ring
(especially of vectors) parallel but oppositely directed
Polar Molecule
molecule with an unequal distribution of charge, resulting in the molecule having a positive end and a negative end
the dissolved substance in a solution
a support or foundation
the state of cohering or sticking together
Aqueous Solution
a solution in water
pH Scale
(chemistry) p(otential of) H(ydrogen)
faithful support for a religion or cause or political party
Hydration Shell
The sphere of water molecules around each dissolved ion
weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH
Surface Tension
a phenomenon at the surface of a liquid caused by intermolecular forces
water loving
lacking affinity for water
Specific Heat
the heat required to raise the temperature of one gram of a substance one degree centigrade
concentration measured by the number of moles of solute per liter of solvent
Heat of Vaporization
heat absorbed by a unit mass of a material at its boiling point in order to convert the material into a gas at the same temperature
pH-H Ion
A measure of hydrogen ion concentration equal to -log [H+] and ranging in value from 0-14
a statement that solves a problem or explains how to solve the problem
compounds that form hydrogen ions when dissolved in water
Rough Endoplasmic Reticulum
System of internal membranes within the cytoplasm. Membranes are rough due to the presence of ribosomes. functions in transport of substances such as proteins within the cytoplasm
Smooth Endoplasmic Reticulum
An endomembrane system where lipids are synthesized, calcium levels are regulated, and toxic substances are broken down.
Golgi Apparatus
a net-like structure in the cytoplasm of animal cells (especially in those cells that produce secretions)
Powerhouse of the cell, organelle that is the site of ATP (energy) production
organelles that capture the energy from sunlight and convert it into chemical energy in a process called photosynthesis
Secretory Vesicles
contain secretions that will be discharged from the cell these vesicles will perform exocytosis (fusing with the plasma membrane to empty contents)
Make proteins
whiplike tails found in one-celled organisms to aid in movement
two tiny structures located in the cytoplasm near the nuclear envelope
short structures projecting from a cell and containing bundles of microtubules that move a cell through its surroundings or move fluid over the cell’s surface
Integral Proteins
Typically transmembrane proteins with hydrophobic regions that completely span the hydrophobic interior of the membrane.
Peripheral Proteins
Protein appendages loosely bound to the surface of the membrane and not embedded in the lipid bilayer.
any of various compounds composed of fatty acids and phosphoric acid and a nitrogenous base
Passive Diffusion
The movement of substances into or out of cells without the expenditure of energy or the involvement of transport proteins in the cell membrane. Also called simple diffusion.
Active Diffusion
movement from LOW to High areas of concentration. Requires enegry
Active Transport
transport of a substance (as a protein or drug) across a cell membrane against the concentration gradient
Activation Energy
the energy that an atomic system must acquire before a process (such as an emission or reaction) can occur
Free Energy
energy that is available to do work
the period of the cell cycle during which the nucleus is not undergoing division, typically occurring between mitotic or meiotic divisions
first and longest phase of mitosis, during which the chromosomes become visible and the centrioles separate and take up positions on the opposite sides of the nucleus
the stage in mitosis or meiosis in which the duplicated chromosomes line up along the equatorial plate of the spindle
the stage of meiosis or mitosis when chromosomes move toward opposite ends of the nuclear spindle
the final stage of meiosis when the chromosomes move toward opposite ends of the nuclear spindle
cell division in which the nucleus divides into nuclei containing the same number of chromosomes
(genetics) cell division that produces reproductive cells in sexually reproducing organisms
cells that contain nuclei
cells that do NOT contain nuclei
Endosymbiotic Theory
theory that eukaryotic cells formed from a symbiosis among several different prokaryotic organisms
(genetics) the organic process whereby the DNA sequence in a gene is copied into mRNA
(genetics) the process whereby genetic information coded in messenger RNA directs the formation of a specific protein at a ribosome in the cytoplasm
Lac Operon
a gene system whose operator gene and three structural genes control lactose metabolism in E. coli
an amino acid which can be deaminated to form a pyruvate for use in the glycolytic pathway
Gene Expression
conversion of the information encoded in a gene first into messenger RNA and then to a protein
Monohybrid Crosses
Crosses that examine the inheritance of only one specific trait
Dihybrid Crosses
crosses that examine the inheritance of two different traits
Sex-linked traits
traits that are inherited with sex chromosomes
Multiple Alleles
three or more forms of a gene that code for a single trait
Chi Square
test of statistical significance for categorical date; non-parametric
Incomplete Dominance
one allele is not completely dominant over the other allele
Situation in which both alleles of a gene contribute to the phenotype of the organism
first phase of interphase; cell grows in size
non-dividing, “resting” stage of interphase
S Phase
The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated.
The final period of interphase during which the cell prepares for mitosis.
M Phase
the phase of the cell cycle that includes mitosis and cytokinesis