Question 1

Which of the following best describes the major functions of meiosis in sexually reproducing organisms?

Accepted Answer

Meiosis reduces chromosome number and shuffles chromosomes to produce genetically different gametes.

Question 2

A human cell with 46 chromosomes undergoes meiosis. How many chromosomes will each resulting gamete contain?

Accepted Answer

$$23$$

Question 3

During prophase I of meiosis, homologous chromosomes pair up and exchange genetic material. What is the name of this process and what is its biological significance?

Accepted Answer

Crossing-over; it increases genetic variability among gametes.

Question 4

If a child inherits two different alleles for a gene from their parents, what does this indicate about the homologous chromosomes?

Accepted Answer

The homologous chromosomes carry alternate forms of the same gene.

Question 5

Which equation correctly represents the number of possible chromosomally different zygotes produced by fertilization in humans, assuming no crossing-over?

Accepted Answer

$$(2^{23})^2$

Question 6

What is the difference between the alignment of chromosomes during metaphase I of meiosis and metaphase of mitosis?

Accepted Answer

In metaphase I of meiosis, tetrads align at the spindle equator, while in mitosis, dyads align separately.

Question 7

A patient is diagnosed with Down syndrome. Which chromosomal abnormality is responsible for this condition?

Accepted Answer

Trisomy 21

Question 8

Which syndrome is characterized by the absence of a second sex chromosome (XO) and results in a female phenotype?

Accepted Answer

Turner syndrome

Question 9

During meiosis II, what is the key event that distinguishes it from meiosis I?

Accepted Answer

Sister chromatids separate.

Question 10

Which of the following statements about nondisjunction is correct?

Accepted Answer

Nondisjunction during meiosis I results in both members of a homologous pair going into the same daughter cell.

Question 11

Which phase of meiosis is responsible for the separation of homologous chromosomes?

Accepted Answer

Anaphase I

Question 12

A male with an extra Y chromosome (XYY) is diagnosed with Jacobs syndrome. What is a common characteristic of this syndrome?

Accepted Answer

Taller than average and persistent acne

Question 13

Which of the following best explains why meiosis is essential for maintaining chromosome number across generations?

Accepted Answer

Meiosis produces haploid gametes, so when fertilization occurs, the diploid number is restored.

Question 14

Which of the following is true regarding the genetic makeup of daughter cells produced by mitosis and meiosis?

Accepted Answer

Daughter cells from mitosis are genetically identical to each other and to the parent cell.

Question 15

Which of the following events increases genetic variation during meiosis?

Accepted Answer

Crossing-over between nonsister chromatids

Question 16

A karyotype of a male with Klinefelter syndrome would show which chromosomal composition?

Accepted Answer

47, XXY

Question 17

Which gene on the Y chromosome is responsible for determining maleness in humans?

Accepted Answer

SRY gene

Question 18

Which process produces sperm in the testes?

Accepted Answer

Spermatogenesis

Question 19

What is the result of meiosis in terms of the number and type of daughter cells produced?

Accepted Answer

Four haploid daughter cells

Question 20

Which of the following statements about Barr bodies is correct?

Accepted Answer

Barr bodies are inactivated extra X chromosomes.

Meiosis and the Genetic Basis of Sexual Reproduction

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