Question 1

Which of the following best describes the main outcome of meiosis in sexually reproducing organisms?

Accepted Answer

It produces four haploid cells that are genetically distinct from each other and from the parent cell.

Question 2

During fertilization, what is restored in the resulting zygote?

Accepted Answer

The diploid number of chromosomes

Question 3

A karyotype of a human cell shows 46 chromosomes. What is the ploidy of this cell?

Accepted Answer

Diploid ($$2n)$$

Question 4

Which of the following statements about homologous chromosomes is correct?

Accepted Answer

They contain the same genes in the same positions but may have different alleles.

Question 5

If a diploid organism has a haploid number $$n = 12$$, how many chromosomes will be present in a gamete produced by meiosis?

Accepted Answer

$$12$$

Question 6

Which process during meiosis is primarily responsible for generating new combinations of alleles within a chromosome?

Accepted Answer

Crossing over

Question 7

A cell with three or more complete sets of chromosomes is described as:

Accepted Answer

Polyploid

Question 8

Which of the following best explains why siblings from the same parents can look very different from each other?

Accepted Answer

Crossing over and independent assortment during meiosis create genetic diversity.

Question 9

What is the result if nondisjunction occurs during meiosis I?

Accepted Answer

Half of the gametes will have an extra chromosome ($$n+1) $$and half will have one less ($$n-1).$$

Question 10

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

Accepted Answer

Anaphase I

Question 11

A human cell with 47 chromosomes is most likely the result of:

Accepted Answer

Nondisjunction during meiosis

Question 12

Which of the following equations correctly represents the chromosome number after meiosis in a diploid organism?

Accepted Answer

$$n$$

Question 13

In which phase of meiosis does crossing over typically occur?

Accepted Answer

Early prophase I

Question 14

Which of the following is a direct consequence of independent assortment during meiosis?

Accepted Answer

Each gamete receives a random mix of maternal and paternal chromosomes.

Question 15

A geneticist observes a karyotype with three copies of chromosome 21. What is the most likely explanation for this observation?

Accepted Answer

Nondisjunction during meiosis leading to trisomy 21 (Down syndrome)

Question 16

Which of the following best describes the difference between mitosis and meiosis?

Accepted Answer

Mitosis produces genetically identical cells, meiosis produces genetically diverse cells.

Question 17

If a nondisjunction event occurs during meiosis II, what is the expected outcome in the gametes?

Accepted Answer

Half the gametes will be normal, one will have an extra chromosome ($$n+1$$), and one will have one less ($$n-1).$$

Question 18

Which of the following scenarios best illustrates the concept of genetic recombination?

Accepted Answer

A gamete contains a chromosome with a mix of maternal and paternal alleles due to crossing over.

Question 19

Which of the following is NOT a direct result of meiosis?

Accepted Answer

Production of genetically identical gametes

Question 20

If an organism is tetraploid ($$4n) $$and its haploid number is $$n = 8$$, how many chromosomes are in its somatic cells?

Accepted Answer

$$32$$

Meiosis: Mechanisms and Biological Significance

Study Guide - Practice Questions