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96 Cards in this Set
- Front
- Back
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adaptations |
exquisitely constructed components that interact to help an organism survive and reproduce |
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natural selection |
the process in which traits that confer advantages in survival and reproduction are retained in the population, and the traits that are disadvantageous disappear |
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morphology |
an organism's size, shape, and composition |
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equilibrium |
when a certain trait, such as beak size, does not change in a population |
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stabilizing selection |
the process that produces the equilibrium state |
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traits |
a distinguishing quality or characteristic |
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characters |
a distinguishing quality or characteristic (synonym) |
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species |
populations of varied individuals that may or may not change through time |
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fecundity |
term demographers use for the ability to produce offspring |
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continuous variation |
traits grade smoothly from one extreme to the other, with all the intermediate types represented
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discontinuous variation |
a number of distinct types exist with no intermediates
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convergence |
the evolution of similar adaptations in unrelated groups of animals |
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placental mammals |
mammals which nourish their young in the uterus during long pregnancies |
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marsupials |
nonplacental mammals that rear their young in external pouches
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blending inheritance |
assumes that the father and father each contribute a hereditary substance that mixes to determine the characteristics of the offspring |
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variants |
traits with only two forms |
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crosses |
matings
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Fk generation |
populations, founding one is the first
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genes |
particles where the observed characteristics of organisms are determined jointly by
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gametes |
eggs and sperm
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independent assortment |
genes equally likely to be transmitted
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chromosome |
small linear bodies contained in every cell and replicated during cell division. crucial feature of cellular anatomy
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nucleus |
the body of a cell
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mitosis |
process of ordinary cell division
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diploid |
organisms where the chromosomes come in homologous pairs
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homologous pairs |
pairs whose members have similar shapes and staining patterns
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meiosis |
special form of cell division leading to the production of gametes
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haploid |
cells that contain only one copy of each chromosome
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zygote |
when a haploid sperm and haploid egg united, a diploid this is formed
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alleles |
different varieties of a single gene
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homozygous |
individuals with two copies of the same allele
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heterozygous |
individuals with copies of two different alleles
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genotype |
the particular combination of genes or alleles that an individual carries |
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phenotype |
the observable characteristics of the organism
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dominant |
individuals with only one copy have the same phenotype
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recessive |
has no effect on phenotype in heterozygotes
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recombination |
phenomenon where sexual reproduction shuffles genes that affect different traits thereby producing new combinations of traits |
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locus |
a particular site on a particular chromosome where genes for a particular character are |
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genome |
all of the genes carried on all of the chromosomes
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linked |
when loci for different traits occur on the same chromosome, they are said to be this
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unlinked |
when loci are on different chromosomes, they are said to be this
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crossing over |
when genes on one chromosome are shifted from one member of a homologous pair to the other
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DNA |
contained in chromosomes, contains the information essential to life
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bases |
attached to each sugar on the backbone of DNA. can be either adenine, cytosine, guanine, or thymine
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protein coding genes |
DNA in these specify the structure of proteins |
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enzymes |
type of protein that regulates much of the biochemical machinery of organisms |
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regulatory genes |
determined the conditions under which the message encoded in a protein coding gene will be expressed
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biochemical pathways |
a complicated tangle of branches
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proteins |
constructed of amino acids, the sequence of which determine their properties
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amino acids |
make up proteins, 20 different types of these
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primary structure |
the sequence of amino acid side chains
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tertiary structure |
the 3D shape of the folded protein
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hemoglobin |
a protein that transports oxygen from the lungs to the tissues via red blood cells
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sickle-cell anemia |
caused by a single change in the primary sequence of amino acids in the hemoglobin molecule, common among people in West Africa and among African-Americans
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codons |
three letter words which specify a particular amino acid
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RNA |
similar to DNA, but has a slightly different chemical backbone and thymine is substituted with uracil
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uracil |
denoted by U, present in RNA
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mRNA |
the first type of RNA that aids protein synthesis |
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tRNA |
amino acid molecules are bound to these, each molecule has a triplet of bases (anticodon) at a particular site
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anticodon |
a triplet of bases on tRNA located at a particular site
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ribosomes |
small cellular organelles
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organelles |
cellular components that perform a particular function
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prokaryotes |
does not have a chromosome or cell nucleus
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eukaryotes |
have chromosomes and a cell nucleus
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introns |
a noncoding sequence
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exons |
a protein coding sequence
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repressor |
a protein that binds to one of the two regulatory sequences, preventing the protein coding genes from being transcribed
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activator |
binds to a DNA sequence, greatly increasing the rate at which the protein coding genes are transcribed
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combinatorial control |
the existence of multiple regulatory sequences allows for this
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spliceosome |
organelles that splice the mRNA in eukaryotes after the introns have been snipped out
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ncRNA |
RNA that does not code
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miRNA |
a short ncRNA segment, plaus an important role of regulating the translation of mRNA into protein
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lncRNA |
longer RNA segments that have a wide variety of functions and may be especially important in regulating the expression of genes during development |
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population genetics |
looking more closely at what happens to genes in populations that are undergoing natural selection is the domain of this |
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genotypic frequency |
the fraction of the population that carries that genotype
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gene frequency |
the frequency of an allele
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Hardy-Weinberg equilibrium |
when no other forces are operating, this happens when genotypic frequencies reach stable proportions in just one generation
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modern synthesis |
a powerful explanation of organic evolution
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environment variation |
when the phenotypic expression of all characters depends on the environment in which the organism develops, it leads to this
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mutations |
when DNA is damaged and the message it carries is altered
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mate guarding |
when males remain in the copulatory position securely anchored to females by large genital hooks
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sex ratio |
the relative number of males and females |
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canalized |
when the same phenotype is in a wide range of enironments |
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plastic |
when the phenotype can be adjusted depending on the environment |
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positively correlated |
when two characters work well with each other
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negatively correlated |
when two characters do not work well with eachother
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pleiotropic effects |
genes that affect more than one character are said to have this
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correlated response |
when selection on one trait affects another trait
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maladaptive |
less fit
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sampling variation |
when the distribution of black and red balls among the small urn varies, it is called this |
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genetic drift |
when the frequency of an allele in the population changes by chance alone
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fixation |
when an allele is entirely lost in a population and all individuals in these populations are identical at the locus in question |
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camera-type eyes |
a single opening in the front of the lens, which projects an image on photoreceptive tissue (humans, other vertebrates, some invertebrates)
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compound eyes |
many very small separate photoreceptors build up an image composed of a grid of dots, something like a television image
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development |
the process of growth and differentiation
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lactate |
the ability to produce milk for young |
