Download Unit 6 Practice and Answers (Answers or on "sticky note" on PDF file)

Unit6 Practice
AP Biology
Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) During a study session about evolution, one of your fellow students remarks, "The giraffe stretched
its neck while reaching for higher leaves; its offspring inherited longer necks as a result." Which
statement is most likely to be helpful in correcting this student's misconception?
A) Characteristics acquired during an organism's life are generally not passed on through genes.
B) Overproduction of offspring leads to a struggle for survival.
C) Disuse of an organ may lead to its eventual disappearance.
D) Spontaneous mutations can result in the appearance of new traits.
E) Only favorable adaptations have survival value.
1)
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
The following questions refer to Figure 22.1, which shows an outcrop of sedimentary rock whose strata are labeled A-D.
Figure 22.1
2) Which stratum should contain the greatest proportion of extinct organisms?
2)
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
3) Which of these naturalists synthesized a concept of natural selection independently of Darwin?
A) Thomas Malthus
B) Gregor Mendel
C) John Henslow
D) Charles Lyell
E) Alfred Wallace
3)
4) In Darwin's thinking, the more closely related two different organisms are, the
A) less likely they are to have the same genes in common.
B) more similar their habitats are.
C) more similar they are in size.
D) less similar their DNA sequences are.
E) more recently they shared a common ancestor.
4)
1
5) Which statement best describes the evolution of pesticide resistance in a population of insects?
A) Insects observe the behavior of other insects that survive pesticide application, and adjust
their own behaviors to copy those of the survivors.
B) Individual members of the population slowly adapt to the presence of the chemical by
striving to meet the new challenge.
C) Offspring of insects that are genetically resistant to the pesticide become more abundant as
the susceptible insects die off.
D) All insects exposed to the insecticide begin to use a formerly silent gene to make a new
enzyme that breaks down the insecticide molecules.
5)
6) The theory of evolution is most accurately described as
A) an educated guess about how species originate.
B) an idea about how acquired characteristics are passed on to subsequent generations.
C) an opinion that some scientists hold about how living things change over time.
D) an overarching explanation, supported by much evidence, for how populations change over
time.
E) one possible explanation, among several scientific alternatives, about how species have come
into existence.
6)
7) Which definition of evolution would have been most foreign to Charles Darwin during his
lifetime?
A) descent with modification
B) the appearance of new varieties and new species with the passage of time
C) change in gene frequency in gene pools
D) populations becoming better adapted to their environments over the course of generations
E) the gradual change of a population's heritable traits over generations
7)
8) Which of these is the smallest unit upon which natural selection directly acts?
A) an individual's genome
B) an individual's phenotype
C) a population's gene frequency
D) a species' gene frequency
E) an individual's genotype
8)
Use the following information to answer the questions below.
A large population of laboratory animals has been allowed to breed randomly for a number of generations. After several
generations, 25% of the animals display a recessive trait (aa), the same percentage as at the beginning of the breeding
program. The rest of the animals show the dominant phenotype, with heterozygotes indistinguishable from the homozygous
dominants.
9) What is the most reasonable conclusion that can be drawn from the fact that the frequency of the
recessive trait (aa) has not changed over time?
A) The two phenotypes are about equally adaptive under laboratory conditions.
B) There has been a high rate of mutation of allele A to allele a.
C) There has been sexual selection favoring allele a.
D) The population is undergoing genetic drift.
E) The genotype AA is lethal.
10) What is the estimated frequency of allele A in the gene pool?
A) 0.05
B) 0.25
C) 0.75
2
D) 1.00
E) 0.50
9)
10)
11) What proportion of the population is probably heterozygous (Aa) for this trait?
A) 0.50
B) 1.00
C) 0.25
D) 0.75
E) 0.05
11)
12) You sample a population of butterflies and find that 42% are heterozygous at a particular locus.
What should be the frequency of the recessive allele in this population?
A) 0.30
B) 0.09
C) 0.49
D) 0.70
E) Allele frequency cannot be determined from this information.
12)
13) Gene flow is a concept best used to describe an exchange between
A) individuals.
B) chromosomes.
C) males and females.
D) species.
E) populations.
13)
14) Mules are relatively long-lived and hardy organisms that cannot, generally speaking, perform
successful meiosis. Consequently, which statement about mules is true?
A) They have a relative evolutionary fitness of zero.
B) Mutations cannot occur in their genomes.
C) Their offspring have less genetic variation than the parents.
D) When two mules interbreed, genetic recombination cannot occur by meiotic crossing over, but
only by the act of fertilization.
E) If crossing-over happens in mules, then it must be limited to prophase of mitosis.
14)
15) A biologist discovers two populations of wolf spiders whose members appear identical. Members
of one population are found in the leaf litter deep within the woods. Members of the other
population are found in the grass at the edge of the woods. The biologist decides to designate the
members of the two populations as two separate species. Which species concept is this biologist
most closely utilizing?
A) ecological
B) morphological
C) biological
D) phylogenetic
15)
16) A hypothetical mutation in a squirrel population produces organisms with eight legs rather than
four. Further, these mutant squirrels survive, successfully invade new habitats, and eventually give
rise to a new species. The initial event, giving rise to extra legs, would be a good example of
A) allometry.
B) species selection.
C) punctuated equilibrium.
D) habitat selection.
E) changes in homeotic genes.
16)
17) An early consequence of the release of oxygen gas by plant and bacterial photosynthesis was to
A) cause iron in ocean water and terrestrial rocks to rust (oxidize).
B) prevent the formation of an ozone layer.
C) make life on land difficult for aerobic organisms.
D) change the atmosphere from oxidizing to reducing.
E) make it easier to maintain reduced molecules.
17)
3
18) Which free-living cells were the earliest contributors to the formation of Earth's oxidizing
atmosphere?
A) endosymbionts
B) seaweeds
C) mitochondria
D) chloroplasts
E) cyanobacteria
18)
19) Which event is nearest in time to the end of the period known as snowball Earth?
A) Cambrian explosion
B) oxygenation of Earth's seas and atmosphere
C) evolution of mitochondria
D) evolution of true multicellularity
E) Permian extinction
19)
20) In their laboratory simulations of the early Earth, Miller and Urey observed the abiotic synthesis of
A) genetic systems.
B) complex organic polymers.
C) DNA.
D) liposomes.
E) amino acids.
20)
4