bio midterm 1 practice exam

Question 1

Of these organisms, which would be the best to use as a model organism to study the eukaryotic cell cycle?
A. potato plants
B. E. coli, a bacterium
C. yeast
D. giraffes
E. dogs

Answer 1

C. Yeast

Question 2

Which of the following correctly describes a typical animal life cycle?
A. There is no zygote produced.
B. The zygote cannot do mitosis.
C. The diploid phase is only a single cell.
D. It is asexual.
E. The products of meiosis cannot do mitosis.

Answer 2

E. The products of meiosis cannot do mitosis.

Question 3

Chromosomes are composed of
A. DNA, proteins and sugars.
B. DNA and RNA.
C. DNA and proteins.
D. DNA and sugars.
E. DNA only.

Answer 3

C. DNA and proteins.

Question 4

Approximately how many genes would you expect to find on an typical human chromosome?
A. 200 to 1000
B. 5000 to 10,000
C. 10,000 to 15,000
D. 15,000 to 20,000
E. impossible to answer, because chromosomes do not have fixed gene numbers

Answer 4

A. 200 to 1000

Question 5

What is the correct order of events in the cell cycle?
A. S (synthesis), mitosis, G2, G1
B. G2, mitosis, S (synthesis), G1
C. mitosis, S (synthesis), G1, G2
D. G1, S (synthesis), G2, mitosis
E. G2, G1, S (synthesis), mitosis

Answer 5

D. G1, S (synthesis), G2, mitosis

Question 6

Two chromosomes that carry alleles for the same characters at the same positions on the chromosome, but can specify different values of some characters, are called
A. homologous chromosomes.
B. heterologous chromosomes.
C. complementary chromosomes.
D. polyploid chromosomes.
E. sister chromosomes.

Answer 6

A. homologous chromosomes.

Question 7

If a diploid worm has 28 chromosomes in its somatic cells (body cells), then the cells arising from mitosis and cytokinesis of a somatic cell will have ________ chromosomes each and the cells arising from meiosis and cytokinesis will have ___________ chromosomes each.
A. 28 . . . . 28
B. 56 . . . . 28
C. 28 . . . . 56
D. 14 . . . . 28
E. 28 . . . . 14

Answer 7

E. 28 . . . . 14

Question 8

Sister chromatids are
A. found only when a cell is not actively dividing.
B. identical copies of a chromosome joined together at the centromere.
C. formed when chromatids separate during cell division.
D. made only of DNA.
E. unique to bacteria.

Answer 8

B. identical copies of a chromosome

Question 9

This question concerns the purple- and white-flowered pea plants that Mendel studied. Purple is dominant to white. If a heterozygous plant is crossed to a white flowered plant, and if 200 progeny are recovered, approximately how many of the progeny will be in each class?
A. 200 purple, 0 white
B. 150 purple, 50 white
C. 100 purple, 100 white
D. 50 purple, 150 white
E. 0 purple, 200 white

Answer 9

C. 100 purple, 100 white

Question 10

The study of how genes are passed from one generation to another is called A. cytogenetics.
B. cellular genetics.
C. population genetics.
D. transmission genetics.
E. biochemical genetics.

Answer 10

D. transmission genetics.

Question 11

11. In class we discussed incomplete dominance in snapdragon. The genotype RR produces red flowers; genotype Rr produces pink flowers; genotype rr produces white flowers. If you self-pollinated a pink-flowered plant, what would the offspring look like?
    A. all pink
    B. all red
    C. all white
    D. 50% pink, 50% white
    E. 25% red, 50% pink, 25% white

Answer 11

E. 25% red, 50% pink, 25% white

Question 12

Genotype is to phenotype as __________________ is to _________________. A. a sock . . . a shoe
B. left . . . right
C. a court trial . . . a verdict
D. multiplication . . . division
E. a cake recipe . . . a cake

Answer 12

E. a cake recipe . . . a cake

Question 13

The physical basis of Mendel’s segregation principle is
A. the separation of sister chromatids in mitosis.
B. the separation of sister chromatids in meiosis II.
C. the separation of homologues in meiosis I.
D. the separation of egg cells and sperm cells during gamete formation. E. the separation of homologous chromosomes during mitosis.

Answer 13

C. the separation of homologues in meiosis I.

Question 14

A change in the frequencies of alleles in the gene pool of a population over a few generations is called
A. genetic drift.
B. microevolution.
C. mutation.
D. disruptive selection.
E. directional selection.

Answer 14

B. microevolution.

Question 15

Genetic drift resulting from a disaster that drastically reduces population size is called
A. natural selection.
B. gene flow.
C. a bottleneck effect.
D. nonrandom mating.
E. sympatric speciation.

Answer 15

C. a bottleneck effect.

Question 16

Broccoli and cabbages are both descended from the same wild mustard and can still interbreed. The existence of these two vegetables is an example of
A. speciation
B. artificial selection.
C. natural selection.
D. genetic drift.
E. hybridization.

Answer 16

B. artificial selection.

Question 17

Long-legged cheetahs are well-adapted to catching prey. The ancestor of the cheetah is believed to have had relatively short legs. The evolution of long-legged cheetahs from short-legged ancestors is most likely an example of
A. stabilizing selection.
B. genetic drift.
C. analogous structures.
D. directional selection.
E. sexual selection.

Answer 17

D. directional selection

Question 18

If natural selection acted over many generations to increase the average length of the leaves in a species of grass plant, this would be an example of
A. disruptive selection.
B. directional selection.
C. sexual selection.
D. species selection.
E. stabilizing selection

Answer 18

E. stabilizing selection

Question 19

In statistical terms, genetic drift can be compared to
A. driving to work slowly some days, quickly other days.
B. very rarely getting food poisoning from undercooked meat.
C. failing every math test but passing every chemistry test.
D. replacing a light bulb and getting an electrical shock.
E. attempting shots from the free throw line in basketball.

Answer 19

E. attempting shots from the free throw line in basketball.

Question 20

The process of mutation
A. is unimportant in evolution.
B. results in ‘devolution’, or backwards evolution.
C. provides variability on which natural selection can act, but not variability on which genetic drift can act.
D. is rare (on a per gene per generation basis).
E. tends to affect all members of a population in the same way at the same time.

Answer 20

D. is rare (on a per gene per generation basis).

Question 21

Male deer have large antlers, at least in part, to help them compete with other males for access to mates. This is an example of
A. disruptive selection.
B. mate selection.
C. domestic selection.
D. sexual selection.
E. competitive selection.

Answer 21

D. sexual selection.

Question 22

Suppose that an antibiotic kills 99.9% of a bacterial population. If natural selection is operating, you would expect the next generation of bacteria
A. to be more resistant to that antibiotic.
B. to die out due to the drastic decrease in population size.
C. to be less contagious than the previous generation.
D. to be just as susceptible to that antibiotic as was the previous generation. E. to be non-infectious.

Answer 22

A. to be more resistant to that antibiotic.

Question 23

Which of the following taxonomic categories is the most inclusive? A. genus
B. order
C. class
D. family
E. phylum

Answer 23

E. phylum

Question 24

How could you create a new species of plant in a greenhouse?
A. by interspecific hybridization and experimentally-induced polyploidy
B. by blasting your material with X-rays to see what happens
C. by changing the growth conditions in one part of the greenhouse and letting natural selection do its work
D. by adding a selection pressure, like mice that eat the fruits before they ripen
E. by putting half the plants in a separate greenhouse

Answer 24

A. by interspecific hybridization and experimentally-induced polyploidy

Question 25

Which of the following is an example of behavioural reproductive isolation?
A. two species of snails that are physically unable to make genital contact with each other, due to their shells winding on opposite directions
B. two species of frogs which produce only sterile hybrids
C. two species of flowering plants, one species shedding pollen in the spring, one shedding pollen in the summer
D. two species of butterflies, one living in Norway, and one living in Kenya
E. two species of birds which do not respond to each other’s mating displays

Answer 25

E. two species of birds which do not respond to each other’s mating displays

Question 26

Coconuts have hair and mammals have hair. The presence of hair in both, however, is not useful in determining their evolutionary relationships. Why not? A. Coconut hair is found on the coat of the seed, but nowhere else on the plant. However, mammal hair is found all over the mammalian body. B. Coconut hair is not ‘real’ hair.
C. Coconut hair and mammal hair are not homologous structures. D. Coconut hair and mammal hair are not analogous structures. E. All coconuts are hairy, but some mammals, such as pigs and people, don’t have a lot of hair.

Answer 26

C. Coconut hair and mammal hair are not homologous structures.

Question 27

In the biological species concept, what is the criterion for distinguishing one species from another?
A. morphological dissimilarity
B. DNA sequence similarity
C. different geographic location
D. reproductive incompatibility
E. biochemical incompatibility

Answer 27

D. reproductive incompatibility