Question 1

Which of the following best describes the image shown in the first figure (Image 1)?

Accepted Answer

A karyotype, which is a photographic display of all the chromosomes in a cell, used to detect chromosomal abnormalities.

Question 2

What information can be determined from the karyotype shown in Image 1?

Accepted Answer

The presence of chromosomal abnormalities such as extra or missing chromosomes.

Question 3

In the context of Image 1, which pair of chromosomes determines the genetic sex of a human individual?

Accepted Answer

The 23rd pair, also known as the sex chromosomes (XX for female, XY for male).

Question 4

Refer to Image 2. What is the biological significance of the chiasmata observed in the electron micrograph?

Accepted Answer

They are the sites where crossing over occurs, leading to genetic recombination during meiosis.

Question 5

How does the process illustrated by the chiasmata in Image 2 contribute to evolution?

Accepted Answer

By increasing genetic variation through recombination, which provides raw material for natural selection.

Question 6

If a human cell has $$N = 23$$ homologous pairs, how many possible combinations of chromosomes can result from independent assortment alone?

Accepted Answer

$$2^{23} = 8$$,388,608$$

Question 7

Which of the following events occurs during Meiosis I but NOT during Meiosis II?

Accepted Answer

Homologous chromosomes separate and crossing over occurs.

Question 8

A mutation occurs in a gene located at a specific locus on chromosome 7. What does the term 'locus' refer to?

Accepted Answer

The physical location of a gene on a chromosome.

Question 9

Which of the following is NOT a process that produces genetic variation in sexual life cycles?

Accepted Answer

Binary fission

Question 10

A plant alternates between a multicellular diploid sporophyte and a multicellular haploid gametophyte. What is this life cycle called?

Accepted Answer

Alternation of generations

Question 11

Which of the following statements correctly distinguishes meiosis from mitosis?

Accepted Answer

Meiosis involves two divisions, occurs in germ cells, and produces four haploid daughter cells with increased genetic variation; mitosis involves one division, occurs in somatic cells, and produces two genetically identical diploid daughter cells.

Question 12

Which of the following best explains why sexual reproduction is advantageous for evolution?

Accepted Answer

It increases genetic variability, which facilitates adaptation and speeds up evolution.

Question 13

During which stage of meiosis does crossing over occur, and what is its outcome?

Accepted Answer

Prophase I; homologous chromosomes exchange genetic material, resulting in recombinant chromosomes.

Question 14

A scientist observes a cell with two unfused haploid nuclei. This is most likely a stage in the life cycle of which organism?

Accepted Answer

Fungi

Question 15

Which of the following best describes independent assortment?

Accepted Answer

The random orientation of homologous chromosome pairs during meiosis I, resulting in genetic variation.

Question 16

If a mutation occurs that prevents crossing over during meiosis, what is the most likely consequence?

Accepted Answer

Reduced genetic variation among gametes.

Question 17

Which of the following is a direct result of random fertilization?

Accepted Answer

Each offspring has a unique combination of genes from both parents.

Question 18

In a human karyotype, what would be the chromosomal composition of a normal male?

Accepted Answer

46 chromosomes, including one X and one Y chromosome.

Question 19

Which of the following is NOT a feature of homologous chromosomes?

Accepted Answer

They are identical copies created during S phase of the same cell cycle.

Meiosis and Sexual Life Cycles: Structured Study Notes

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드