ch 11 3rd test

if a given population has 30 RR individuals, 10 Rr individuals, and 10 rr individtuals, what is the allele frequency of R?

.7

a gene has two alleles, D and d. the frequency of the D allele is 0.2. what is the frequency of the d allele?

0.8

in the following figure, the flying bird moves permanently into the population shown on land. as a result, the allele frequency of A in the population changes from

1 to .75

what is the total number of alleles present for any given gene in a population of 100 individuals?

200

evolution can be described as

a change in the genetic characteristics of a population of organisms over time

which of the following statements concerning evolution is FAlsed

an indvidual that is better adapted than others in a population will always be more reproductively succesfful

insecticides are used to kill insects . however, insecticide resistant insects are being found. what is the mechanism for this new insect trait?

an insect with a random mutation is not killed by the insecticide and reproduces

which of the following is not likely to be a cause of rapid evolution in a population?

an organism that reproduces very slowly

the result of convergent evolution is___traits

analogous

convergent evolution produces

analogous characteristics

disruptive selection operates whenever

both extremes of the phenotype are more successful

the wings of a bird and the wings of a bat both forma the front appendages(arms). the bird wing is covered by feathers, and the bat wing consists of a thin layer of skin stretcheed between "finger"bones. are the wings of the bird and bat homologous or analogous?

both; they are homologous because they both evolved from a front appendage, but analougous because they evolved differently

what is genetic drift

chance evolutionary change occurring in small populations

both mammals and octopi have evolved similar eye structures. this is an example of

convergent evolution

two unrelated species evolving to look more similar due to environmental pressures is called

convergent evolution

two different species may have similar features because of

descent from a common ancestor

genetic varation is based on

diffences is genotypes between the individuals in a population

a scientist is studying beak lenght in a species of hummingbird. the scientist est a pop of birds with beaks ranging from very small to very long and allows the pop to breed for 10 yrs. a the end of the experiment, she finds that the majority of birds in the population have very long beaks. this is an example of the ___ selection patterne of natural selection

directional

which of ther following is not a mode of natural seltion?

domiant selection

convergent evolution occurs when natural selection causes distantly related organisms to

evolve similar structures in response to similar environmental challenges.

both insects and humans evolved jointed legs to allow locomotion on land. these structures are considered analogous because insects and humans

evolved from different ancestors

some finches on the galapagos islands eat insects, and unusual food for finches to eat. these finches

fill roles that birds other than finches would fill in other places.

the following image is an example of

gene flow

two populations of geese live near each other. as time passes, the populations are becomig more genetically alike. this prob due to__

gene flow

while on a campting trip, you collect a white tadpole from a pond and take it home. the tadpole develops into a while bullfrong. when the frog gets too big, you release it into a local pond. the next year, several white bullfrogs are observed int the pond. this is an example of

gene glow

a used car is shipped from australia to the us. stowed away in teh trunk of the car is a pice of wood infectd with austrailian termites. once in the us, the buyer of the car finds the rotting wooks and dumps it on the side of the road. the termites survive and est a colony on the side of the road but do not mate with local termite pop. this an example of

genetic drift

a population of 8250 mice occupies the sand dunes in a costal area. a severe hurricane washes out several miles of sand dunes. as a result, only 50 mice remain. the pop has experienced

horizontal gene transfer

an example of evolution that has been readily observed is

increase resistance of bacteria to an antibiotic that is used to iill them

although millions of prarire chickens once occupied illionois, in 1993 only 50 remained. starting in 1992, scintist moved almost 300 prarie chickens form large populations in other states to illinoise to ___

introduce genetic variation back into

gene glow between two poplulations

makes the genetic composition of the two populations more similar

Sexual selection can result in an increase frequency of alleles which

may be harmful to the individual's survival but is always beneficial to its reproductive rate

compared to a large mainland pop, genetic drift in small island population is

more important because of a smaller gene pool

for a population to evolve, there must be genetic differences between organisms in that population. these differences arise by

mutation

new alleles arise by

mutation

the colr of a certain species of beetle is determined by a single gene. two beetles homozygous for green coloration(meaning they have two copies of the green allele) produce a single offspring with brown coloration. brwon color appeared in this offspring as a result of

mutation

the orginal source of genetic varation within a pop is__

mutation

which of the following is true with regard to mutations

mutations appear without regard to environmental pressures.

evolutionary changes occur when__ acts upon populations containing individuals with genetic differences

natural selection

several related bird species live in a desert. one species is much smaller than the other species. this species neests in holes in cacti. bc the bird is so small, it can easily squeeze between the spines of the cactus and create a well-protected nest. this is an example of

natural selection

the only mechanism of evolutionary change is not influence by chance events is

natural selection

how do natural selection and sexual selection differ

natural selection increases the frequency of alleles that contribute to survival, but sexual selection may increase the frequency of alleles that are not beneficial to survival

which of the following is not a step in the evolutionary process

new genes are introduced into a population when members of that population mate with members of other species and produce offspring

during gene glow

new individuals contribute their alleles to the gene pool of a population

a mutation in a gene produces the identical protien to the orginal gene and therefore, and identical trait. will evolution act upon this mutation?

no because evolution acts upon phenotypes

ub light causes mutations within skin cells. is ub light a major driving force in the evolution of animals

no only mutations in gmetes will be passed on the next gerneration only mutations that are passed on to offspring contribute to evolution

jean-bapiste lamark proposed that populations evolve when traits acquired during the lifetime of a parent are passed down to offspring. what is wrong with this proposal?

only changes in the dna sequence of an organism can be inherited. traits acquire throughout life generally do not involve dna

in natural selection__that increase survival and reproductive success become more common in a population

phenotypes

which of the following is an example of gene glow

pollen from population A plant lands on a population B plant

a fisher man cathches one trout from each of two ponds. pondA contains 100 trout and pond B contains 1000 torut. which population is more affected by the fisherman?

pond A; the fisher man has a greater likelihood of completely removing alleles from the gene pool my taking fish from the small pops

which of the following is not a cause of evolution

stable environmental conditons

gene glow occurs

when an individual migrates between two otherwise isolated populations of a species

a student with step throuat is told to take the drug for two weeks. after a week, the student feels beeter and stops taking the drug. two months later, the student again shows symptoms of strep throat and decides to finish the leftover antibiotic rather than going to the doctor again. two months later, the student develops strep throat for a third time and returns to the doctor. this time, the antibiotic does not work. the doctor runs a test and discovers that the bacterial strain the student is carrying is antibiotic resistant. what most likely happened?

when the student stopped taking the drug, a small number of bacteria--those that were more drug resistant--still survived in his body. those bacteria repopulated his throat and over time, drug-resistant alleles became more common.