Question 1

Which of the following best describes the outcome of meiosis in animals?

Accepted Answer

It produces four haploid cells, each with half the chromosome number of the parent cell.

Question 2

During fertilization in humans, what is restored in the resulting zygote?

Accepted Answer

The diploid number of chromosomes ($$2n)$$

Question 3

Which statement about homologous chromosomes is correct?

Accepted Answer

They carry the same genes at the same loci, but may have different alleles.

Question 4

A fruit fly (Drosophila melanogaster) has 8 chromosomes in its somatic cells. How many chromosomes are present in its gametes?

Accepted Answer

$$4$$

Question 5

Which process during meiosis is primarily responsible for increasing genetic variation among offspring?

Accepted Answer

Crossing over between homologous chromosomes during late prophase I

Question 6

If an organism has 6 distinct autosomes plus sex chromosomes, how many chromosomes would a diploid somatic cell contain?

Accepted Answer

$$14$$

Question 7

Which phase of meiosis is characterized by the separation of homologous chromosomes?

Accepted Answer

Anaphase I

Question 8

What is the term for a cell that contains only one of each type of chromosome?

Accepted Answer

Haploid

Question 9

Which of the following events occurs during late prophase I of meiosis?

Accepted Answer

Crossing over between homologous chromosomes

Question 10

A human somatic cell contains 46 chromosomes. After meiosis, how many chromosomes will each gamete contain?

Accepted Answer

$$23$$

Question 11

Which of the following best explains why maternal age is a risk factor for trisomy disorders such as Down syndrome?

Accepted Answer

Eggs arrest in prophase I for years, increasing the chance of nondisjunction during meiosis.

Question 12

Which of the following is NOT a difference between mitosis and meiosis?

Accepted Answer

Both mitosis and meiosis produce four daughter cells.

Question 13

What is the result of nondisjunction during meiosis?

Accepted Answer

Gametes with abnormal numbers of chromosomes (aneuploidy)

Question 14

Which of the following best describes independent assortment?

Accepted Answer

The random distribution of maternal and paternal chromosomes to gametes during meiosis I

Question 15

If a cell is tetraploid ($$4n$$), how many sets of chromosomes does it contain?

Accepted Answer

$$4$$

Question 16

Which of the following is a consequence of crossing over during meiosis?

Accepted Answer

Increased genetic variation among offspring

Question 17

A karyotype of an individual with Down syndrome would show:

Accepted Answer

An extra copy of chromosome 21 (trisomy 21)

Question 18

Which of the following best describes a bivalent during meiosis?

Accepted Answer

A structure consisting of two homologous chromosomes, each with two sister chromatids

Question 19

Which phase of meiosis II is characterized by the alignment of chromosomes at the metaphase plate?

Accepted Answer

Metaphase II

Question 20

Which of the following scenarios would most likely result in aneuploidy in a human zygote?

Accepted Answer

A nondisjunction event during meiosis I in the egg-producing parent

Meiosis and Chromosome Inheritance

Study Guide - Practice Questions