Question 1

Which of the following best explains why offspring produced by sexual reproduction are genetically unique compared to their parents?

Accepted Answer

Because chromosomes are randomly assorted and crossing over occurs during meiosis.

Question 2

During which phase of meiosis do homologous chromosomes separate, reducing the chromosome number from diploid to haploid?

Accepted Answer

Anaphase I

Question 3

If a human cell has 46 chromosomes at the start of meiosis, how many chromosomes will each gamete have after meiosis is complete?

Accepted Answer

$$23$$

Question 4

Which process during meiosis is primarily responsible for the creation of recombinant chromosomes?

Accepted Answer

Crossing over

Question 5

A karyotype is used to study chromosomes. Which feature is NOT typically used to pair homologous chromosomes in a karyotype?

Accepted Answer

Orientation to the nucleus

Question 6

Which of the following events occurs during the S-phase of the cell cycle?

Accepted Answer

Chromosomes duplicate, forming sister chromatids.

Question 7

In humans, how many possible combinations of chromosomes can result from independent assortment alone, given $$n = 23$$ pairs of chromosomes?

Accepted Answer

$$2^{23}$$

Question 8

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

Accepted Answer

Both mitosis and meiosis II separate sister chromatids, but mitosis occurs in somatic cells and meiosis II in gametes.

Question 9

A cell with a diploid number of $$2n = 6$$ undergoes meiosis. How many chromosomes will be present in each gamete produced?

Accepted Answer

$$3$$

Question 10

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

Accepted Answer

Production of recombinant chromosomes with mixed parental genes

Question 11

If a cell is observed to have two sets of chromosomes, one from each parent, what term best describes its ploidy?

Accepted Answer

Diploid

Question 12

During which stage of meiosis do homologous chromosomes align at the metaphase plate?

Accepted Answer

Metaphase I

Question 13

Which of the following mechanisms does NOT contribute to genetic variation in sexually reproducing organisms?

Accepted Answer

Replication of DNA without errors

Question 14

A human male karyotype is missing a homolog for the Y chromosome. What is the most likely explanation?

Accepted Answer

The Y chromosome does not have a true homolog in males.

Question 15

Which of the following best describes random fertilization?

Accepted Answer

The random pairing of sperm and egg cells, increasing genetic diversity.

Question 16

If a cell undergoes meiosis and produces four gametes, but one gamete has an extra chromosome, what is the most likely cause?

Accepted Answer

Nondisjunction occurred during anaphase I or II.

Question 17

Which equation correctly represents the number of possible gamete combinations due to independent assortment for an organism with $$n$$ pairs of chromosomes?

Accepted Answer

$$2^n$$

Question 18

During meiosis, at what point do cells become haploid?

Accepted Answer

After anaphase I, when homologous chromosomes have separated.

Question 19

Which of the following is true regarding somatic cells and gametes in humans?

Accepted Answer

Somatic cells are diploid and gametes are haploid.

Question 20

A cell with $$2n = 8$$ chromosomes undergoes meiosis. After meiosis II, how many chromosomes will each gamete contain?

Accepted Answer

$$4$$

Inheritance, Meiosis, and Genetic Variation: Study Notes for General Biology

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