Question 1

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

Accepted Answer

To produce gametes with half the number of chromosomes as the parent cell

Question 2

During which phase of meiosis does crossing over occur, and what is its biological significance?

Accepted Answer

Prophase I; it increases genetic variation among gametes

Question 3

A human cell with a diploid number of chromosomes ($$2n = 46) $$undergoes meiosis. How many chromosomes will each resulting gamete contain?

Accepted Answer

$$23$$

Question 4

Which of the following events is unique to meiosis and does NOT occur in mitosis?

Accepted Answer

Synapsis and formation of tetrads

Question 5

If a cell containing 20 chromosomes (diploid) undergoes meiosis, how many chromosomes will each daughter cell have at the end?

Accepted Answer

$$10$$

Question 6

Which formula correctly predicts the number of possible chromosome combinations due to independent assortment in gametes, given $$n$$ pairs of chromosomes?

Accepted Answer

$$2^n$$

Question 7

A human male can produce approximately how many different combinations of sperm due to independent assortment alone?

Accepted Answer

$$2^{23}$$, or about 8 million combinations

Question 8

Which of the following is NOT a source of genetic variation in sexually reproducing populations?

Accepted Answer

Replication of DNA during S phase

Question 9

What is the difference between homologous chromosomes and sister chromatids?

Accepted Answer

Homologous chromosomes are similar in shape and size and carry genes for the same traits, while sister chromatids are identical copies formed after DNA replication

Question 10

During anaphase I of meiosis, which of the following occurs?

Accepted Answer

Homologous chromosomes separate and move to opposite poles

Question 11

Which phase of meiosis is the longest and most complex, and what key event occurs during this phase?

Accepted Answer

Prophase I; homologous chromosomes undergo synapsis to form tetrads

Question 12

Which of the following statements about meiosis II is correct?

Accepted Answer

Meiosis II is identical to mitosis except it occurs in haploid cells

Question 13

A karyotype is used to:

Accepted Answer

Organize chromosomes of a cell in relation to number, size, and type

Question 14

Which chromosomal abnormality is associated with Down syndrome?

Accepted Answer

Trisomy of chromosome 21

Question 15

Which of the following best explains why variation produced by meiosis is important for populations?

Accepted Answer

It provides the raw material for natural selection

Question 16

Which of the following correctly matches the phase of meiosis with its main event?

Accepted Answer

Metaphase I: Tetrads align on the metaphase plate

Question 17

In humans, how many pairs of autosomes are present in a typical somatic cell?

Accepted Answer

22

Question 18

Which process during meiosis increases the number of possible gamete types beyond what is produced by independent assortment alone?

Accepted Answer

Crossing over between nonsister chromatids

Question 19

Which of the following statements about gametes produced by meiosis is correct?

Accepted Answer

They are haploid and genetically unique due to crossing over and independent assortment

Question 20

Which of the following is true regarding the alignment of chromosomes during metaphase I of meiosis?

Accepted Answer

Homologous pairs (tetrads) align randomly on the metaphase plate, leading to independent assortment

17-Meiosis: Mechanisms, Chromosomal Basis, and Genetic Variation

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