Question 1

Which of the following best describes the difference between homologous chromosomes and sister chromatids?

Accepted Answer

Homologous chromosomes are chromosomes of the same type from different parents, while sister chromatids are identical copies formed after DNA replication.

Question 2

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

Accepted Answer

Crossing over occurs during prophase I and increases genetic variation among gametes.

Question 3

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

Accepted Answer

$$23$$

Question 4

Which of the following statements about diploid and haploid cells is correct?

Accepted Answer

Diploid cells have two sets of chromosomes, while haploid cells have one set.

Question 5

Which process is responsible for the formation of genetically unique gametes in sexually reproducing organisms?

Accepted Answer

Meiosis

Question 6

If a cell has $$n$$ chromosomes after meiosis I, how many chromosomes will it have after meiosis II?

Accepted Answer

$$n$$

Question 7

Which of the following best explains why Down syndrome occurs?

Accepted Answer

The presence of an extra copy of chromosome 21 (trisomy 21).

Question 8

What is the main difference between somatic cells and gametes in humans?

Accepted Answer

Somatic cells are diploid, while gametes are haploid.

Question 9

During fertilization, which equation correctly represents the restoration of chromosome number in humans?

Accepted Answer

$$n + n = 2n$$

Question 10

Which of the following events increases genetic diversity during meiosis?

Accepted Answer

Crossing over between homologous chromosomes

Question 11

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

Accepted Answer

The number and structure of chromosomes in a cell

Question 12

Which statement correctly describes the outcome of meiosis II?

Accepted Answer

Sister chromatids separate, resulting in four haploid cells.

Question 13

If a species has a diploid number of $$2n = 16$$, how many chromosomes will its gametes contain?

Accepted Answer

$$8$$

Question 14

Which of the following is true about the process of crossing over?

Accepted Answer

It occurs between non-sister chromatids of homologous chromosomes.

Question 15

Which phase of meiosis is responsible for the reduction in chromosome number?

Accepted Answer

Meiosis I

Question 16

Which of the following best explains the genetic consequences of independent assortment during meiosis?

Accepted Answer

It results in random combinations of maternal and paternal chromosomes in gametes.

Question 17

Which equation represents the number of possible gamete combinations due to independent assortment, where $$n is $$the haploid number?

Accepted Answer

$$2^n$$

Question 18

Which of the following is NOT a difference between mitosis and meiosis?

Accepted Answer

Mitosis involves crossing over, while meiosis does not.

Question 19

Which of the following best describes a gene?

Accepted Answer

A section of DNA that codes for a specific protein or trait.

Cell Division, Chromosomes, and Genetic Variation: Study Notes for General Biology

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