WorksheetsAP Biology Unit 7: Natural Selection Quiz
Total questions: 34
Worksheet time: 3hrs 50mins
Fragments of DNA have been extracted from the remnants of extinct wooly mammoths, amplified, and sequenced. These can now be used to
introduce into relatives, such as elephants, certain mammoth traits
clone live wooly mammoths
study the relationships among wooly mammoths and other wool-producers
understand the evolutionary relationships among members of related taxa
During a study session about evolution, one of your fellow students remarks, ʺThe giraffe stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a result.ʺ Which statement is most likely to be helpful in correcting this studentʹs misconception?
Characteristics acquired during an organismʹs life are generally not passed on through genes.
Spontaneous mutations can result in the appearance of new traits.
Only favorable adaptations have survival value.
Disuse of an organ may lead to its eventual disappearance.
Refer to the figure, which shows an outcrop of sedimentary rock whose strata are labeled. Which stratum should contain the greatest proportion of extinct organisms?
A
B
C
D
Refer to the figure, which shows an outcrop of sedimentary rock whose strata are labeled. If ʺxʺ indicates the location of fossils of two closely related species, then fossils of their most-recent common ancestor are most likely to occur in which stratum?
A
B
C
D
Charles Darwin was the first person to propose
that evolution occurs
a mechanism for how evolution occurs
that the Earth is older than a few thousand years
a mechanism for evolution that was supported by evidence
In Darwinʹs thinking, the more closely related two different organisms are, the
more similar their habitats are
less similar their DNA sequences are
more recently they shared a common ancestor
less likely they are to have the same genes in common
Natural selection is based on all of the following except
genetic variation exists within populations.
the best-adapted individuals tend to leave the most offspring.
individuals who survive longer tend to leave more offspring than those who die young.
populations tend to produce more individuals than the environment can support.
individuals adapt to their environments and, thereby, evolve
Which statement about natural selection is most correct?
Adaptations beneficial in one habitat should generally be beneficial in all other habitats as well.
Different species that occupy the same habitat will adapt to that habitat by undergoing the same genetic changes.
Adaptations beneficial at one time should generally be beneficial during all other times as well.
Well-adapted individuals leave more offspring, and thus contribute more to the next generationʹs gene pool, than do poorly adapted individuals.
Given a population that contains genetic variation, what is the correct sequence of the following events, under the influence of natural selection?
1. Well-adapted individuals leave more offspring than do poorly adapted individuals.
2. A change occurs in the environment.
3. Genetic frequencies within the population change.
4. Poorly adapted individuals have decreased survivorship.
2 → 4 → 1 → 3
4 → 2 → 1 → 3
4 → 1 → 2 → 3
During drought years on the Galapagos, small, easily eaten seeds become rare, leaving mostly large, hard-cased seeds that only birds with large beaks can eat. If a drought persists for several years, what should one expect to result from natural selection?
Small birds gaining larger beaks by exercising their mouth parts.
Small birds mutating their beak genes with the result that later-generation offspring have larger beaks.
Small birds anticipating the long drought and eating more to gain weight and, consequently, growing larger beaks.
More small-beaked birds dying than larger-beaked birds. The offspring produced in subsequent generations have a higher percentage of birds with large beaks.
Which of the following statements is an inference of natural selection?
Subsequent generations of a population should have greater proportions of individuals that possess traits better suited for success in unchanging environments
An individual organism undergoes evolution over the course of its lifetime.
Habitats do not generally have unlimited resources.
Natural populations tend to reproduce to their full biological potential.
Which of the following must exist in a population before natural selection can act upon that population?
Genetic variation among individuals
Variation among individuals caused by environmental factors
Sexual reproduction
The treeʹs horizontal axis is a timeline that extends from 100,000 years ago to the present; the vertical axis represents nothing in particular. The labeled branch points on the tree (V—Z) represent various common ancestors. Letʹs say that only since 50,000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species.
How many separate species, both extant and extinct, are depicted in this tree?
2
3
4
6
The treeʹs horizontal axis is a timeline that extends from 100,000 years ago to the present; the vertical axis represents nothing in particular. The labeled branch points on the tree (V—Z) represent various common ancestors. Letʹs say that only since 50,000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species.
According to this tree, what percent of the species seem to be extant (i.e., not extinct)?
25%
33%
50%
66%
The treeʹs horizontal axis is a timeline that extends from 100,000 years ago to the present; the vertical axis represents nothing in particular. The labeled branch points on the tree (V—Z) represent various common ancestors. Letʹs say that only since 50,000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species. Which of the five common ancestors, labeled V—Z, has given rise to the greatest number of species, both extant and extinct?
V
W
X
Y
Z
The treeʹs horizontal axis is a timeline that extends from 100,000 years ago to the present; the vertical axis represents nothing in particular. The labeled branch points on the tree (V—Z) represent various common ancestors. Letʹs say that only since 50,000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species.
Which of the five common ancestors, labeled V—Z, has been least successful in terms of the percent of its derived species that are extant?
V
W
X
Y
Z
DDT was once considered a ʺsilver bulletʺ that would permanently eradicate insect pests.
Today, instead, DDT is largely useless against many insects. Which of these would have been required for this pest eradication effort to be successful in the long run?
Larger doses of DDT should have been applied.
All habitats should have received applications of DDT at about the same time.
The frequency of DDT application should have been higher.
None of the individual insects should have possessed genomes that made them resistant to DDT.
Of the following anatomical structures, which is homologous to the wing of a bird?
Dorsal fin of a shark
Hindlimb of a kangaroo
Wing of a butterfly
Flipper of a cetacean
If two modern organisms are distantly related in an evolutionary sense, then one should expect that
they live in very different habitats.
they should share fewer homologous structures than two more closely related organisms.
their chromosomes should be very similar.
they shared a common ancestor relatively recently.
Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, these bones having developed from very similar embryonic tissues. How do biologists interpret these similarities?
By the principle of convergent evolution
By proposing that humans, bats, and dolphins share a common ancestor
Which of the following pieces of evidence most strongly supports the common origin of all life on Earth?
All organisms require energy.
All organisms use essentially the same genetic code.
All organisms reproduce.
All organisms show heritable variation
Logically, which of these should cast the most doubt on the relationships depicted by an evolutionary tree?
None of the organisms depicted by the tree ate the same foods.
Some of the organisms depicted by the tree had lived in different habitats.
The skeletal remains of the organisms depicted by the tree were incomplete (i.e., some bones were missing).
Relationships between DNA sequences among the species did not match relationships between skeletal patterns.
Ichthyosaurs were aquatic dinosaurs. Fossils show us that they had dorsal fins and tails, as do fish, even though their closest relatives were terrestrial reptiles that had neither dorsal fins nor aquatic tails. The dorsal fins and tails of ichthyosaurs and fish are
homologous.
examples of convergent evolution.
Which of these is a statement that Darwin would have rejected?
Environmental change plays a role in evolution.
The smallest entity that can evolve is an individual organism.
Individuals can acquire new characteristics as they respond to new environments or situations.
Inherited variation in a population is a necessary precondition for natural selection to operate.
About which of these did Darwin have a poor understanding?
that individuals in a population exhibit a good deal of variation
that much of the variation between individuals in a population is inherited
the factors that cause individuals in populations to struggle for survival
the sources of genetic variations among individuals
Each of the following has a better chance of influencing gene frequencies in small populations than in large populations, but which one most consistently requires a small population as a precondition for its occurrence?
mutation
non-random mating
genetic drift
natural selection
HIVʹs genome of RNA includes code for reverse transcriptase (RT). The HIV genome also codes for protease (PR), an enzyme that acts later in infection by cutting long viral polyproteins into smaller, proteins. Both RT and PR represent potential targets for antiretroviral drugs. Drugs called nucleoside analogs (NA) act against RT, whereas drugs called protease inhibitors (PI) act against PR. Which of these represents the treatment option that is most likely to avoid the production of drug-resistant HIV (assuming no drug interactions or side effects)?
using a series of NAs, one at a time, and changed about once a week
using a single PI, but slowly increasing the dosage over the course of a week
using high doses of NA and a PI at the same time for a period not to exceed 1 day
using moderate doses of NA and of two different PIʹs at the same time for several months
The DNA polymerases of all cellular organisms have proofreading capability. This capability tends to reduce the introduction of
extra genes by gene duplication events.
chromosomal translocation.
genetic variation by mutations.
proofreading capability into prokaryotes.
In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of allele a is 0.2. What is the frequency of individuals with Aa genotype?
0.20
0.32
0.42
0.80
In a hypothetical population of 1,000 people, tests of blood-type genes show that 160 have the genotype
AA, 480 have the genotype AB, and 360 have the genotype BB. What is the frequency of the B allele?
0.001
0.002
0.600
When we say that an individual organism has a greater fitness than another individual, we specifically mean that the organism
lives longer than others of its species
competes for resources more successfully than others of its species
mates more frequently than others of its species
leaves more viable offspring than others of its species
Dog breeders maintain the purity of breeds by keeping dogs of different breeds apart when they are fertile. This kind of isolation is most similar to which of the following reproductive isolating mechanisms?
reduced hybrid fertility
hybrid breakdown
mechanical isolation
habitat isolation
Which gas was least abundant in Earthʹs early atmosphere, prior to 2 billion years ago?
O2
CO2
CH4
H2O
Several scientific laboratories across the globe are involved in research concerning the origin of life on Earth. Which of these questions is currently the most problematic and would have the greatest impact on our understanding if we were able to answer it?
How can amino acids, simple sugars, and nucleotides be synthesized abiotically?
How can RNA molecules catalyze reactions?
How did RNA sequences come to carry the code for amino acid sequences?
How could polymers involving lipids and/or proteins form membranes in aqueous environments?
