MODULE 9: MEIOSIS AND SEXUAL REPRODUCTION

Question 1

A triploid cell contains three sets of homologous chromosomes. If a cell of a diploid species that normally has 42 chromosomes per cell is triploid, this cell would be expected to have which of the following sets of chromosomes?

Answer 1

63 chromosomes in 3 sets of 21 chromosomes

Question 2

Which of the following processes might produce a human zygote with 45 chromosomes?

Answer 2

an error during anaphase of meiosis occurring in either an egg or sperm

Question 3

Which of the following characteristics do homologous chromosomes exhibit?

Answer 3

They carry information for the same traits.

Question 4

Which of the following statements defines a genome?

Answer 4

the complete set of an organism’s genes and other DNA sequences

Question 5

Which of the following statements correctly describes a karyotype?

Answer 5

It is an organized image of a cell’s chromosomes.

Question 6

How do cells at the completion of meiosis compare with cells that are in prophase of meiosis I?

Answer 6

The cells have half the number of chromosomes and one-fourth the amount of DNA.

Question 7

During which of the following processes do sister chromatids separate from each other?

Answer 7

during both mitosis and meiosis II

Question 8

Asexual reproduction occurs during which of the following processes?

Answer 8

mitosis

Question 9

For the following questions, match the key event of meiosis with the stages listed below.

I. Prophase I V. Prophase II
II. Metaphase I VI. Metaphase II
III. Anaphase I VII. Anaphase II
IV. Telophase I VIII. Telophase II

Homologous chromosomes are aligned at the equator of the spindle.

Answer 9

II

Question 10

Which diagram represents anaphase I of meiosis?

Answer 10

I

Question 11

Somatic cells of roundworms have four individual chromosomes per cell. How many chromosomes would you expect to find in an ovum from a roundworm?

Answer 11

Two

Question 12

Which of the following statements describes a major difference between meiosis II and mitosis in a diploid animal?

Answer 12

Meiosis II occurs in a haploid cell, while mitosis occurs in diploid cells.

Question 13

During which of the following processes do homologous pairs of chromosomes align adjacent to one another at the metaphase plate of a cell?

Answer 13

metaphase I of meiosis

Question 14

Which of the following processes occurs when homologous chromosomes cross over in meiosis I?

Answer 14

Corresponding segments of non-sister chromatids are exchanged.

Question 15

The bulldog ant has a diploid number of two chromosomes. Therefore, following meiosis, each daughter cell will have a single chromosome. In addition to mutations, how might genetic diversity be generated in this species?

Answer 15

crossing over and random fertilization

Question 16

If a cell has completed meiosis I and the first cytokinesis, and is just beginning meiosis II, which of the following is an appropriate description of its genetic contents?

Answer 16

It has half the amount of DNA as the cell that began meiosis.

Question 17

Independent assortment of chromosomes is a result of which of the following processes?

Answer 17

the random way each pair of homologous chromosomes lines up at the metaphase plate during meiosis I

Question 18

In eukaryotes, genetic information is passed to the next generation by processes that include mitosis or meiosis. Which of the following explanations correctly identifies the process and supports the claim that heritable information is passed from one generation to another?

Answer 18

In asexual reproduction, a single individual is the sole parent and passes copies of its genes to its offspring without the fusion of gametes.

Question 19

Genetic variation leads to genetic diversity contributes to the evolution of populations of organisms. Which of the following statements best represents the connection between reproduction and evolution?

Answer 19

Sexual reproduction increases genetic variation because random mutations can be shuffled between organisms.

Question 20

Which of the following processes occurs in meiosis but not in mitosis?

Answer 20

synapsis of chromosomes

Question 21

When chiasmata can first be seen in cells using a microscope, which of the following processes has most likely occurred?

Answer 21

prophase I

Question 22

DNA was isolated from three different cell types of the same organism, the relative DNA content for each type was determined, and the results were plotted on the graph shown in the figure below. Refer to the graph to answer the following questions.

A bar graph shows DNA content (n) from 0 to 8. Three samples have the following amounts of DNA: Sample I, 2 units; sample II, 4 units, sample III, 1 unit.

Which sample of DNA might be from a cell that stopped the process of cell division in G0 phase of the cell cycle prior to meiosis?

Answer 22

I