Question 1

Which of the following best describes the difference between autosomes and sex chromosomes in humans?

Accepted Answer

Autosomes do not determine sex, while sex chromosomes (X and Y) determine the individual's sex.

Question 2

A karyotype is most useful for which of the following purposes?

Accepted Answer

Photographing and organizing chromosomes by type to detect chromosomal abnormalities.

Question 3

If a human cell has 46 chromosomes, how many chromosomes will each gamete have after meiosis?

Accepted Answer

$$23$$

Question 4

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

Accepted Answer

Crossing over and independent assortment

Question 5

What is the result of meiosis in terms of chromosome number and genetic identity compared to the parent cell?

Accepted Answer

Four haploid cells, genetically different from the parent cell and each other

Question 6

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 unique combinations of alleles.

Question 7

During which phase of meiosis do homologous chromosomes separate and move to opposite poles of the cell?

Accepted Answer

Anaphase I

Question 8

A gene locus refers to:

Accepted Answer

The physical location of a gene on a chromosome

Question 9

If a cell undergoes meiosis but fails to separate sister chromatids during Anaphase II, what is the likely outcome?

Accepted Answer

Some gametes will have an abnormal number of chromosomes (n+1 or n-1).

Question 10

Which of the following equations correctly represents the number of possible chromosome combinations in human gametes due to independent assortment?

Accepted Answer

$$2^{23}$$

Question 11

A woman is born with approximately 1 million eggs, but only about 300-400 are ovulated during her reproductive years. What is the biological significance of this?

Accepted Answer

It increases the chance of genetic diversity and reproductive success.

Question 12

Which of the following best describes homologous chromosomes?

Accepted Answer

They carry the same types of genes in the same locations but may have different alleles.

Question 13

Which event occurs during Prophase I of meiosis that does NOT occur during mitosis?

Accepted Answer

Homologous chromosomes pair up and crossing over occurs.

Question 14

If a mutation occurs in the BRCA1 gene locus, what is a possible consequence?

Accepted Answer

Increased risk of breast cancer.

Question 15

Which of the following statements about alleles is correct?

Accepted Answer

Alleles are different forms of a gene found at the same locus.

Question 16

A zygote is formed when:

Accepted Answer

Two haploid gametes fuse during fertilization.

Question 17

Which of the following best explains why meiosis requires two cell divisions?

Accepted Answer

To reduce the chromosome number by half and separate sister chromatids.

Question 18

If a sperm cell contains 23 chromosomes, how many chromosomes are present in a human zygote after fertilization?

Accepted Answer

$$46$$

Question 19

Which of the following is a direct result of crossing over during meiosis?

Accepted Answer

Exchange of genetic material between homologous chromosomes

Question 20

Which of the following best describes the outcome of mitosis compared to meiosis?

Accepted Answer

Mitosis produces two diploid cells identical to the parent; meiosis produces four haploid cells genetically different from the parent.

Cell Division: Meiosis, Chromosomes, and Genetic Variation

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