Biology 123 SI
Mock Exam 4
1. The coccyx (a.k.a. the tailbone) helps to attach the tail to the body in most animals. However,
in humans, it has lost functionality. This is most closely and example of:
A. convergent evolution
B. a vestigial structure
C. homology
D. adaptation
E. None of the above.
2. Which of the following is an example of convergent evolution?
A. Blind cave fish possess remnants of eye structures under their scales.
B. Cats and bats have similar skeletal configurations in their forelimbs.
C. Dolphins and sharks have a similar fusiform (streamlined) body shape.
D. Both gymnosperms and angiosperms produce seeds.
E. Human embryos and fish embryos both have pharyngeal pouches.
3. Which of the following is NOT true regarding natural selection?
A. In natural selection, individuals with certain heritable traits survive and reproduce at higher
rates than other individuals because the traits are fit to the environment.
B. Over time, natural selection can increase the match between a species and the environment.
C. If an environment changes, or if individuals move to a new environment, natural selection
may result in adaptation to these new conditions sometimes giving rise to a new species.
D. B and C are both not true.
E. A, B, and C are true.
4. A population of zooplankton is exposed to a small number of predator fish that feed on the
larger-sized (adult) zooplankton. Which of the following predictions would most likely occur
based on the principles of natural selection?
A. The predatory fish will evolve smaller mouths so that they do not drive their prey to
extinction.
B. The predatory fish will evolve poor eyesight so as to preserve their food supply.
C. The zooplankton will become sexually mature at larger sizes.
D. Adult zooplankton will start to reach sexual maturity when they are still relatively small.
E. All of the above could happen.
5. Darwin proposed that new species evolve from ancestral forms by
A. The gradual accumulation of adaptations to changing or different environments.
B. The struggle for limited resources.
C. The excessive production of offspring.
D. The inheritance of acquired adaptations to the environment.
E. The accumulation of mutations.
6. Which of the following is a source of genetic variation?
A. The formation of new alleles through mutation.
B. Rapid reproduction.
C. Sexual reproduction.
D. B and C
E. All of the above.
7. Which of the following is NOT a requirement for Hardy-Weinberg equilibrium?
A. No mutations
B. No natural selection
C. A very large population
D. Random mating
E. All of the above are requirements for Hardy-Weinberg equilibrium.
8. In a population that is in Hardy-Weinberg equilibrium for two alleles, C and c, 16% of the
population show the recessive trait. What percent of the population are heterozygous?
A. 84%
B. 48%
C. 32%
D. 54%
E. 36%
9. If a population has the following genotype frequencies-- AA = .64, Aa= .32, and aa= .4—what
are the allele frequencies?
A. A=.8, a= .2
B. A= .64, a= .4
C. A=.32, a=.2
D. A=.16, a=.1
E. None of the above.
10. A small group of aliens from Mars come and land on planet earth. They are now separated
from the rest of their species and suffer from severely reduced genetic variation. This is an
example of:
A. the bottleneck effect
B. genetic drift
C. the founder effect
D. disruptive selection
E. C and D
11. Genetic drift is likely to be seen in a population
A. that has a high migration rate.
B. that has a low mutation rate.
C. in which natural selection is occurring.
D. that is very small
E. for which environmental conditions are changing
12. Sparrows with averaged length wings fare storms better than sparrows with long or short
wings. Over time, this would result in:
A. Disruptive selection
B. Stabilizing selection
C. Directional selection
D. Sexual selection
E. relative fitness
13. True or false: It is believed that eventually natural selection will produce the perfect
organism.
14. The males of different species of fruit fly that live in the same parts of the Hawaiian Islands
have different elaborate courtship rituals. What type of reproduction isolation does this
represent?
A. gametic isolation
B. habitat isolation
C. temporal isolation
D. postzygotic barriers
E. behavioral isolation
15. What categorizes a species according to the biological species concept?
A. a population or group of populations that have similar phenotypic characteristics
B. a population or group of populations in which members are a very close match according to
genetic testing
C. a population or group of populations with the same number of chromosomes
D. a population or group of populations that can interbreed in nature, but do not interbreed with
other such groups in nature
E. All of the above.
16. Which of the following is a way that sympatric speciation can occur?
A. After a new food source is introduced, half of a population of trout begin to feed on the new
food source, while the other half continue to feed on the old food source.
B. Different members of the species begin to differ in sexual selection.
C. A large lake’s water line lowers, forming a land mass separating the two halves of the lake, a
species of fish get separated into the two different halves and begin to form two different species
in the different environments.
D. A and B
E. All of the above.
17. Which of the following is an example of a postzygotic barrier?
A. Two squirrel species produce an offspring that is very weak and dies at a very young age.
B. Two sea urchin species have sperm that are incapable of fertilizing eggs of the other species.
C. Of two similar beetle species, one lives in the trees, while the other lives in the ground.
D. Of two similar bird species, one mates in the early fall, while the other mates in the early
spring.
E. None of the above.
18. What is a protocell?
A. The first prokaryote.
B. The group of macromolecules that are considered to be the important precursors to life.
C. A membranous sac with an inside chemistry differing from the chemistry of its surroundings.
D. The environment that helped to support the evolution of life.
E. None of the above.
19. Which period and description below are incorrectly matched?
A. Denovian: Diversification of bony fishes; first tetrapods and insects appear
B. Premian: Radiation of reptiles; origin of most present-day groups of insects; extinction of
many marine and terrestrial organisms at the end of the period (end of the Paleozoic Era)
C. Jurassic: Gymnosperms continue as dominant plants; dinosaurs abundant and diverse
D. Cretaceous: Extensive forests of vascular plants form; first seed plants appear; origin of
reptiles; amphibians dominant
E. All of the above are correctly paired.
20. What were the first replicating molecules?
A. Viruses
B. Phospholipids
C. Proteins
D. DNA
E. RNA
21. Adaptive radiations are often seen after_____________.
A. sexual selection takes place
B. mass extinctions
C. major new evolutionary adaptations, such as flight, occur
D. bacteria and plants both have flagellated gametes
E. B and C
22. Which is the least inclusive grouping below?
A. family
B. class
C. order
D. phylum
E. kingdom
23. What is the focus of the branch of biology called taxonomy?
A. the environment
B. genetics
C. the classification of life-forms by their similarities and differences
D. evolution
E. the history of the field of biology
24. The Permian extinction occurred _____________ years ago and _______ of marine
organismsb ecame extinct.
A. 250 billion, 50%
B. 65.5 million, 50%
C. 250 million, 90%
D. 65.5 million, 90%
25. The Permian extinction was due to ____________.
A. a volcanic eruption
B. a meteorite
C. the loss of coastline due to the formation of Pangea
D. the cause is completely unknown
26. The Cyanobacteria were important in which of the following?
A. Created free oxygen in the atmosphere
B. Formed the Ozone layer
C. Allowed animals to become terrestrial
D. All of the above
27. A baby’s head is much larger in proportion to the rest of its body when compared to the size
of an adult’s head in relation to its body size. This is an example of?
A. Allopatric Growth
B. Allometric Growth
C. Sympatric Growth
D. none of the above
28. _____________ is the process of retaining juvenile characteristics, for example, the
retainment of the head shape of a human when compared to a chimpanzee.
A. Paleomorphosis
B. Allometric Growth
C. Padeomorphosis
D. All of the above
29. If a trait that in a population persists even though it is not better than the other trait options,
but also, seems to be of no advantage it is a product of _____________.
A. balanced selection
B. neutral selection
C. frequency dependent selection
D. none of the above
30. Suppose an environment has not had any sort of natural disaster in quite some time. As a
result of this, the terrain and color of the environment has remained the same. What sort of
selection would a scientist expect to observe?
A. directional
B. destructive
C. stabilizing
D. not enough information given
31. Species that have symbiotic relationships with each other tend to evolve similarly. This is an
example of ___________.
A. allopatric speciation
B. Allen’s Rule
C. natural habituation
D. co-evolution
32. Currently, I have no children. However, in the future I would like to have 2 or 3. I will
effectively be increasing my __________.
A. Genetic contribution to succeeding generations
B. Biological fitness
C. gene drift
D. Both A and B
33. Somatic cell mutations affect natural selection because they are passed on to future
generations of offspring. T or F
34. Which of the following is least likely to represent homology?
A. the wings of a bat and the arm of a human
B. the hemoglobin in a baboon and in a gorilla
C. the brain of a cat and dog
D. the wings of a bird and the wings of a bat
35. The correct way to denote the scientific name of a human is ___________.
A. Homo Sapiens
B. Homo sapiens
C. Homo Sapiens
D. Homo Sapiens
46. Rock strata provides lots of information about the past. In what ways does it support
macroevolution?
A. Radiometric dating
B. Fossil record
C. Iridium deposits around 65.5 million years ago
D. All of the above
E. A and B only