Question 1

Which of the following statements best describes the difference between mitosis and meiosis in terms of genetic variation?

Accepted Answer

Mitosis produces genetically identical cells, while meiosis introduces genetic variation through crossing over and independent assortment.

Question 2

During which stage of meiosis does crossing over occur, and what is the significance of this process?

Accepted Answer

Crossing over occurs during Prophase I, and it increases genetic variation by exchanging segments between homologous chromosomes.

Question 3

A human somatic cell contains 46 chromosomes. After meiosis, how many chromosomes will each gamete contain?

Accepted Answer

$$23$$

Question 4

Which formula correctly calculates the number of possible chromosome combinations due to independent assortment in a species with $$n$$ pairs of chromosomes?

Accepted Answer

$$2^n$$

Question 5

If a diploid cell has $$6$$ picograms (pg) of DNA at the end of interphase, how much DNA will each daughter cell have after mitosis?

Accepted Answer

$$6$$\,pg$

Question 6

Which of the following is TRUE regarding the chromosome number and DNA content during Meiosis I?

Accepted Answer

The chromosome number per cell is halved, but the DNA content per chromosome remains the same.

Question 7

Which process is responsible for producing haploid gametes in humans?

Accepted Answer

Meiosis

Question 8

What is the ploidy of a zygote formed after fertilization in humans?

Accepted Answer

Diploid ($$2n)$$

Question 9

Which of the following best explains why sexual reproduction leads to greater genetic diversity than asexual reproduction?

Accepted Answer

Sexual reproduction involves meiosis and fertilization, which combine genes from two parents and introduce variation through crossing over and independent assortment.

Question 10

During Anaphase I of meiosis, what separates?

Accepted Answer

Homologous chromosomes

Question 11

Which of the following statements about DNA replication in meiosis is correct?

Accepted Answer

DNA replication occurs before Meiosis I, but not before Meiosis II.

Question 12

A karyotype is useful for which of the following purposes?

Accepted Answer

Identifying chromosomal abnormalities and determining the number and types of chromosomes in a cell.

Question 13

Which of the following events contributes most directly to genetic variation in sexually reproducing species?

Accepted Answer

Crossing over during Prophase I and independent assortment during Metaphase I of meiosis.

Question 14

If a human cell has $$46$$ chromosomes before interphase, how many DNA molecules will it have after interphase?

Accepted Answer

$$92$$

Question 15

Which of the following is TRUE about the life cycle of plants?

Accepted Answer

Plants have both haploid and diploid multicellular stages.

Question 16

What is the result of meiosis II in terms of chromosome number and genetic composition?

Accepted Answer

Four haploid cells, each genetically unique.

Question 17

Which of the following best describes a gene?

Accepted Answer

A section of DNA that codes for one polypeptide.

Question 18

Which of the following statements is FALSE regarding the process of fertilization?

Accepted Answer

Fertilization produces haploid cells.

Question 19

Which stage of meiosis is responsible for the separation of sister chromatids?

Accepted Answer

Anaphase II

Question 20

In a species with $$n=4$$ pairs of chromosomes, how many possible combinations of chromosomes can result from independent assortment?

Accepted Answer

$$2^4 = 16$

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

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