chapter 13

Question 1

Which of the following defines a genome?

Answer 1

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

Question 2

Asexual reproduction in Eukaryotes occurs during ________.

Answer 2

B) mitosis

Question 3

Which of the following is a true statement about sexual vs. asexual reproduction?

Answer 3

B) In sexual reproduction, individuals transmit half of their nuclear genes to each of their offspring.

Question 4

Which of the following is true of a species that has a chromosome number of 2n = 16?

Answer 4

C) Each diploid cell has eight homologous pairs.

Question 5

In a plant’s sexual life cycle ________.

Answer 5

B) gametophytes produce gametes by mitosis

Question 6

Which of the following is an example of alternation of generations?

Answer 6

B) A diploid plant (sporophyte) produces, by meiosis, a spore that gives rise to a multicellular, haploid pollen grain (gametophyte).

Question 7

In a human karyotype, chromosomes are arranged in 23 pairs. If we choose one of these pairs, such as pair 14, which of the following do the two chromosomes of the pair have in common?

Answer 7

C) length, centromere position, staining pattern, and traits coded for by their genes

Question 8

Homologous chromosomes ________.

Answer 8

B) carry information for the same traits

Question 9

If meiosis produces haploid cells, how is the diploid number restored for those organisms that spend most of their life cycle in the diploid state?

Answer 9

D) fertilisation

Question 10

The human X and Y chromosomes ________.

Answer 10

C) include genes that determine an individual’s sex

Question 11

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

Answer 11

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

Question 12

Which of the following happens at the conclusion of meiosis I?

Answer 12

A) Homologous chromosomes of a pair are separated from each other

Question 13

Sister chromatids separate from each other during ________.

Answer 13

D) mitosis and meiosis II

Question 14

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

Answer 14

B) synapsis of chromosomes

Question 15

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 15

B) two

Question 16

Which of the following can occur by the process of meiosis but not mitosis?

Answer 16

C) Diploid cells form haploid cells.

Question 17

What is a major difference between meiosis II and mitosis in a diploid animal?

Answer 17

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

Question 18

Crossing over normally takes place during which of the following processes?

Answer 18

B) meiosis I

Question 19

For the duration of meiosis I, each chromosome ________.

Answer 19

B) consists of two sister chromatids joined by a centromere

Question 20

Homologous pairs of chromosomes align opposite of each other at the equator of a cell during ________.

Answer 20

B) meiosis metaphase I

Question 21

Independent assortment of chromosomes occurs during ________.

Answer 21

A) meiosis I only

Question 22

For a species with a haploid number of 23 chromosomes, how many different combinations of maternal and paternal chromosomes are possible for the gametes?

Answer 22

D) about 8 million

Question 23

Independent assortment of chromosomes is a result of ________.

Answer 23

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

Question 24

When homologous chromosomes cross over, what occurs?

Answer 24

C) Corresponding segments of non-sister chromatids are exchanged.

Question 25

How is natural selection related to sexual reproduction as opposed to asexual reproduction?

Answer 25

A) Sexual reproduction results in many new gene combinations, some of which will lead to differential reproduction.

Question 26

The bulldog ant has a diploid number of two chromosomes. Therefore, following meiosis, each daughter cell will have a single chromosome. Diversity in this species may be generated by mutations and ________.

Answer 26

C) crossing over and independent assortment

Question 27

The fastest way for organisms to adapt to a changing environment involves ________.

Answer 27

C) sexual reproduction

Question 28

Genetic variation leads to genetic diversity in populations and is the raw material for evolution. Biological systems have multiple processes, such as reproduction, that affect genetic variation. They are evolutionarily conserved and shared by various organisms.
Which statement best represents the connection between reproduction and evolution?

Answer 28

evolution.

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