Question 1

Which of the following best describes the difference between a genome and a karyotype?

Accepted Answer

A genome refers to all the chromosomes and their genetic information in a cell, while a karyotype is the visual appearance and number of chromosomes in a cell.

Question 2

During sexual reproduction, homologous chromosomes are important because:

Accepted Answer

They contain the same genes at the same locations, but may have different alleles, allowing for genetic variation.

Question 3

What is the ploidy of human gametes produced by meiosis?

Accepted Answer

Haploid ($$n)$$

Question 4

If gametes were diploid instead of haploid, what would happen after fertilization in humans?

Accepted Answer

The resulting zygote would be tetraploid ($$4n$$), leading to abnormal development.

Question 5

Which process is responsible for reducing the chromosome number from diploid to haploid in sexually reproducing organisms?

Accepted Answer

Meiosis

Question 6

Which event during meiosis is primarily responsible for increasing genetic diversity among gametes?

Accepted Answer

Crossing over during prophase I

Question 7

Independent assortment refers to:

Accepted Answer

The random orientation of homologous chromosome pairs during metaphase I of meiosis.

Question 8

Which of the following is a key difference between mitosis and meiosis?

Accepted Answer

Meiosis involves two rounds of cell division, resulting in four haploid cells, while mitosis involves one round, resulting in two diploid cells.

Question 9

A gene is best defined as:

Accepted Answer

A region of DNA that codes for a specific protein.

Question 10

Which of the following scenarios would most likely result in low genetic diversity in a population?

Accepted Answer

A population reproducing exclusively by asexual reproduction.

Question 11

Which formula correctly represents the chromosome number after meiosis in a human cell?

Accepted Answer

$$n = \frac{2n}{2}$$

Question 12

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

Accepted Answer

It creates genetic variation through mechanisms such as crossing over and independent assortment.

Question 13

A cell with a genotype $$AaBb$$ undergoes meiosis. Which of the following best describes the possible gametes produced, considering independent assortment?

Accepted Answer

Gametes could be $$AB$$, $$Ab$$, $$aB$$, or $$ab.$$

Question 14

Which of the following statements about alleles is correct?

Accepted Answer

Alleles are alternative versions of a gene found at the same locus on homologous chromosomes.

Question 15

During which phase of meiosis does crossing over occur?

Accepted Answer

Prophase I

Question 16

Which of the following is NOT a protein job encoded by the genome?

Accepted Answer

Visual appearance of chromosomes

Question 17

If a mutation occurs in a gene that codes for a cell cycle regulator, what is a possible consequence?

Accepted Answer

Uncontrolled cell division, potentially leading to cancer.

Question 18

Which of the following best describes the relationship between genotype and phenotype?

Accepted Answer

Genotype refers to the alleles present at a gene locus, while phenotype is the observable characteristics resulting from those alleles.

Question 19

Which process ensures that no genetic information is lost when homologous chromosomes exchange segments during meiosis?

Accepted Answer

Crossing over occurs at specific loci, so only equivalent regions are swapped.

Meiosis I and Sexual Reproduction: Genetic Variation in Eukaryotes

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