Campbell biology chapter 23. Flashcards

13451779060	T OR F organisms evolve during their lifetimes	false	0
13451779061	Natural selection acts on ______, but ______ evolve	individuals, populations	1
13451779062	Microevolution	change in allele frequencies in a population over generations	2
13451779063	Three mechanisms causes allele frequency change	Natural selection, genetic drift, and gene flow	3
13451779064	Only _____ can cause ______ evolution	Natural selection, adaptive	4
13451779065	Variation in heritable traits is a prerequisite for	evolution	5
13451779066	Mendel is the father of	genetics	6
13451779067	genetic variation is caused by	differences in genes or other DNA segments	7
13451779068	phenotype is	the product of genotype and environmental influences	8
13451779069	natural selection can only act on a phenotype with a	genetic component	9
13451779070	Some phenotypic differences are classified on an	either or basis	10
13451779071	genetic variation can be measured as	gene variability or nucleotide variability	11
13451779072	Some pheontypic variation does not result from ______ differences but from ______ influences	genetic, environmental	12
13451779073	New genes and alleles can arise by	mutation and gene duplication	13
13451779074	sexual reproduction can result in genetic variation by	recombining existing alleles	14
13451779075	Mutation	Random change in nucleotide sequence of DNA	15
13451779076	what type of mutations can be passed to offspring	mutations that occur in gametes	16
13451779077	a point mutation is a change in	one base in a gene	17
13451779078	neutral variation	no selective advantage or disadvantage	18
13451779079	mutation rate is _____ in animals	low	19
13451779080	sexual reproduction can shuffle existing alleles into new combinations	crossing over	20
13451779081	Population	a localized group of individuals capable of interbreeding and producing fertile offspring	21
13451779082	gene pool	all alleles for all loci in a population	22
13451779083	the sum of all alleles is always	1	23
13451779084	hardy weinberg equilibrium	a population where gametes contribute to the next generation randomly and genotype frequencies remain constant	24
13451779085	Five conditions for nonevolving populations	No mutations, random mating, no natural selection, large population, no gene flow	25
13451779086	Three factors bring out the most evolutionary change	Natural selection, genetic drift, gene flow	26
13451779087	adaptive evolution	the match between organisms and their environments	27
13451779088	genetic drift	describes how allele frequencies can fluctuate from one generation to the next	28
13451779089	the founder effect	a few individuals become isolated from a larger population i.e pond getting more shallow	29
13451779090	bottleneck effect	sudden reduction in population size cause by the environment i.e volcano	30
13451779091	Summary of genetic drift	It is significant in small populations it can cause allele frequencies to change at random it can lead to a loss of genetic variation within populations it can cause harmful alleles to become fixed	31
13451779092	Geneflow	the movement of alleles among populations	32
13451779093	T OR F gene flow can decrease and increase the fitness of a population	true	33
13451779094	gene flow is an important agent of	evolutionary change in modern human populations	34
13451779095	evolution by natural selection involves both _____ and ____	chance and sorting	35
13451779096	natural selection brings about adaptive evolution by acting on an organisms	phenotype	36
13451779097	Relative fitness	the contribution an individual makes to the gene pool for the next generation relative to the contributions of other individuals	37
13451779098	Directional selection	favors individuals at one extreme end of the phenotypic range	38
13451779099	Disruptive selection	favors individuals at both extremes of the phenotypic range	39
13451779100	stabilizing selection	favors intermediate variants and acts against extreme phenotypes	40
13451779101	adaptive evolution is a	continuous process	41
13451779102	sexual selection	natural selection for mating success	42
13451779103	sexual dimorphism	marked differences between the sexes in secondary sexual characteristics	43
13451779104	intrasexual selection	direct competition among individuals of one sex for mates of the opposite sex	44
13451779105	intersexual selection	mate choice, individuals of one sex(usually females) are choosy in selecting their mates	45
13451779106	balancing selection	when natural selection maintains stable frequencies or two or more phenotypic forms in a population	46
13451779107	balancing selection includes two things	heterozygote advantage and frequency dependent selection	47
13451779108	heterozygote advantage	when heterozygotes have a higher fitness than do both homozygotes	48
13451779109	frequency dependent selection	the fitness of a population declines if it becomes too common in the population	49
13451779110	Why natural selection cannot fashion perfect organisms	selection can act only on existing variations evolution is limited by historical constraints adaptations are often compromises chance, natural selection, and the environment interact	50