Exam 4 Review

Question 1

The main advantage of sexual reproduction over asexual reproduction is the creation of genetic diversity among offspring. True or false.

Answer 1

True

Question 2

Which division in meiosis is most similar to mitosis (in the sense that chromatids, not chromosomes, are being separated)?

Answer 2

Meiosis II

Question 3

At the end of meiosis I, which of the following is true?
a. the two cells produced are haploid, with two chromatids per chromosome
b. the two cells produced are diploid, with two chromatids per chromosome
c. the two cells produced are haploid, with one chromatid per chromosome
d. the two cells produced are diploid, with one chromatid per chromosome

Answer 3

a. the two cells produced are haploid, with two chromatids per chromosome

Question 4

In metaphase I of meiosis I, in what formation are the chromosomes held along the metaphase plate (center of the cell)?

Answer 4

a double line

Question 5

Which phase of meiosis is characterized by homologous chromosomes experiencing crossing over (the swapping of genetic content)?

Answer 5

prophase I

Question 6

The DNA of a cell is held in the form of chromatin until a cell enters mitosis (or meiosis), at which point it is tightly wound up into chromosomes. T/F

Answer 6

True

Question 7

At the end of mitosis, the term used to refer to the splitting of the cytoplasm of a cell is cytokinesis. T/F

Answer 7

True

Question 8

What phase of mitosis is characterized by the pulling apart of sister chromatids (due to the shortening of spindle fibers)?

Answer 8

anaphase

Question 9

In the metaphase stage of mitosis, in what formation are the chromosomes held along the metaphase plate (center of the cell)?

Answer 9

a single line

Question 10

What phase of mitosis is characterized by the condensation of chromosomes, the disappearance of nuclear membranes, and the appearance of spindle fibers?

Answer 10

prophase

Question 11

The replication (copying) of the DNA of a cell occurs during the prophase stage of mitosis. T/F

Answer 11

False

Question 12

The outcome of mitosis will be two new cells that are genetically identical to each other, and also to the original cell that produced them. T/F

Answer 12

True

Question 13

Asexual reproduction can be much more energy-efficient than sexual reproduction. T/F

Answer 13

True

Question 14

In a habitat with significant geologic diversity, some regions areas exist with very light exposed bedrock, and some regions exist with very dark exposed bedrock. A small rodent species living in this habitat has two different color (camouflage) variants that are currently being favored by natural selection: one with very light fur coloration and one with very dark fur coloration. Which of the following does this example describe?

a. directional selection
b. diversifying/disruptive selection
c. stabilizing selection

Answer 14

b. diversifying/disruptive selection

Question 15

In which of the following should it be easiest to observe evolutionary change happening (in a relatively short period of time)?

a. a species with a short generation time, low genetic diversity, and a low mutation rate
b. a species with a long generation time, high genetic diversity, and a low mutation rate
c. a species with a short generation time, high genetic diversity, and a high mutation rate
d. a species with a long generation time, high genetic diversity, and a high mutation rate

Answer 15

c. a species with a short generation time, high genetic diversity, and a high mutation rate

Question 16

Small populations would be more likely to exhibit the effects of genetic drift (such as a bottleneck effect) than large populations. T/F

Answer 16

True

Question 17

For most natural (wild) populations, it is unlikely that all of the conditions required for Hardy-Weinberg equilibrium will be met. T/F

Answer 17

True

Question 18

Given the Hardy-Weinberg equation (p2 + 2pq + q2= 1.0), and the information that the value of p= .6 and the value of q= .4 in a given population, what would be the expected frequency of the homozygous dominant (AA) genotype?

Answer 18

.36

Question 19

Which of the following represents a condition that would violate Hardy-Weinberg equilibrium?

a. large population size
b. random mating
c. no gene flow into or out of a population
d. a high mutation rate
e. all of the above

Answer 19

d. a high mutation rate

Question 20

All mutations are harmful to the organisms in which they occur. T/F

Answer 20

False

Question 21

Which of the following statements would be true?

a. Artificial selection always tends to produce the same phenotype patterns that would be produced via natural selection.
b. A trait that serves as a beneficial adaptation in one environment will not necessarily be advantageous in all other environments.
c. Evolutionary processes will dependably drive the body structures of organisms toward a “perfect” form.
d. all of the above

Answer 21

b. A trait that serves as a beneficial adaptation in one environment will not necessarily be advantageous in all other environments.

Question 22

Natural selection is a process in which individual organisms have differential survival and reproductive rates, but evolutionary change is a phenomenon that occurs over many generations at the population level (not at the level of individual organisms). T/F

Answer 22

True

Question 23

A community consists of all of the organisms of the same species that exist (and interbreed) in a given area. T/F

Answer 23

False

Question 25

Early scientists interested in how speciation occurs, such as Darwin and Wallace, had a good understanding of DNA structure and the mechanisms by which chromosomes and genes move between generations. T/F

Answer 25

False

Question 26

A ____________mutation causes one incorrect amino acid subunit (with different properties than the “intended” amino acid subunit) to be inserted into a new protein strand, and a _____________mutation will lead to early termination of protein production (by erroneously coding for a “stop codon”).

Answer 26

missense, nonsense

Question 27

If an insertion mutation occurs that changes the DNA sequence “ACTG” to “ACCCTG,” instead, a frameshift mutation (possibly affecting all “downstream” codons in the gene) will have occurred. T/F

Answer 27

True

Question 28

What type of bonding holds the individual amino acid subunits of a new protein strand together?

Answer 28

covalent peptide bonds

Question 29

Which of the following is the molecule that carries an anticodon at one end and will bring the correct amino acid to a growing new protein strand during the production of a protein? a. mRNA b. tRNA c. rRNA

Answer 29

b. tRNA

Question 30

What is the organelle location and specific (nonorganelle) structure responsible for protein production in a cell?

Answer 30

endoplasmic reticulum, ribosome

Question 31

The process of converting an mRNA sequence into the amino acid sequence of a protein is known as transcription. T/F

Answer 31

False

Question 32

You are a geneticist, and you discover that one of your DNA samples, taken from a human skin cell, has a mutation. The third letter of the codon is incorrect. Due to the redundancy of the genetic code, is there a possibility that the mutation will be silent? Yes or no.

Answer 32

Yes

Question 33

Introns are segments of an mRNA molecule that are specifically involved in coding for a peptide chain. T/F

Answer 33

False

Question 34

The enzyme responsible for creating a new mRNA strand would be RNA polymerase. T/F

Answer 34

True