Question 1

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

Accepted Answer

To reduce the chromosome number by half and generate genetic diversity in gametes

Question 2

A fertilized egg is called a zygote. Which process does the zygote undergo to develop into a multicellular organism?

Accepted Answer

Mitosis

Question 3

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

Accepted Answer

Prophase I; it increases genetic variation by exchanging DNA between homologous chromosomes

Question 4

Which of the following statements about homologous chromosomes is correct?

Accepted Answer

They carry the same genes but may have different alleles, and one comes from each parent

Question 5

In humans, somatic cells are diploid. If a human gamete contains $$n = 23$$ chromosomes, how many chromosomes are present in a typical human somatic cell?

Accepted Answer

$$46$$

Question 6

Which of the following best explains why gametes are genetically unique?

Accepted Answer

Because of independent assortment and crossing over during meiosis

Question 7

During metaphase I of meiosis, how are homologous chromosomes arranged and attached to the spindle fibers?

Accepted Answer

Homologous pairs (tetrads) align at the metaphase plate, with each homolog attached to spindle fibers from opposite poles

Question 8

Which of the following events occurs during meiosis I but not during mitosis?

Accepted Answer

Pairing and separation of homologous chromosomes

Question 9

If a fruit fly has a diploid number of $$2n = 8$$, how many chromosomes will be present in each gamete after meiosis?

Accepted Answer

$$4$$

Question 10

Which of the following best describes independent assortment and its contribution to genetic variation?

Accepted Answer

It is the random distribution of homologous chromosomes to gametes during metaphase I, increasing genetic diversity

Question 11

A genetic disorder is caused by nondisjunction during meiosis. Which phase is most likely affected, and what is the result?

Accepted Answer

Anaphase I; homologous chromosomes fail to separate, leading to aneuploid gametes

Question 12

Which of the following is true regarding the chromosome number in gametes and zygotes?

Accepted Answer

Gametes are haploid and zygotes are diploid

Question 13

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

Accepted Answer

Mitosis produces two genetically identical cells, while meiosis produces four genetically unique cells

Question 14

A cell with $$2n = 6$$ undergoes meiosis. After meiosis II, how many chromosomes will each daughter cell contain?

Accepted Answer

$$3$$

Question 15

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

Accepted Answer

Exchange of genetic material between non-sister chromatids of homologous chromosomes

Question 16

Which of the following best explains why genetic variation is important in populations?

Accepted Answer

It allows populations to adapt to changing environments and increases survival chances

Question 17

During which stage of meiosis do homologous chromosomes form tetrads and exchange genetic material?

Accepted Answer

Prophase I

Question 18

If a mutation occurs in a gene on one homologous chromosome, what is the most likely outcome for the gametes produced after meiosis?

Accepted Answer

Half of the gametes will carry the mutated gene, and half will carry the normal gene

Question 19

Which of the following best describes a tetrad?

Accepted Answer

A group of four chromatids formed by the pairing of two homologous chromosomes during prophase I

Question 20

A scientist observes a cell in which homologous chromosomes are being separated to opposite poles. Which stage of meiosis is being observed?

Accepted Answer

Anaphase I

Chapter 10: Meiosis and Sexual Life Cycles - Structured Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard