Question 1

Which of the following best describes the difference between asexual and sexual reproduction in multicellular organisms?

Accepted Answer

Asexual reproduction produces offspring genetically identical to the parent, while sexual reproduction results in genetic variation among offspring.

Question 2

In humans, how many chromosomes are found in a somatic cell and what is the term for this chromosome number?

Accepted Answer

46 chromosomes; diploid

Question 3

What is the specific term for the location of a gene on a chromosome?

Accepted Answer

Locus

Question 4

During meiosis, what is the significance of crossing over in prophase I?

Accepted Answer

It produces recombinant chromosomes, increasing genetic variation among offspring.

Question 5

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

Accepted Answer

$$2^n$$

Question 6

A cell with a diploid number of 6 ($$2n=6) $$undergoes meiosis. How many chromosomes will each resulting gamete contain?

Accepted Answer

3 chromosomes

Question 7

Which of the following events is unique to meiosis and does NOT occur in mitosis?

Accepted Answer

Synapsis and crossing over of homologous chromosomes

Question 8

In the life cycle of plants and some algae, what is the name of the diploid multicellular stage that produces haploid spores by meiosis?

Accepted Answer

Sporophyte

Question 9

Which mechanism contributes to genetic variation by combining DNA from two parents into a single chromosome?

Accepted Answer

Crossing over

Question 10

If a human sperm cell (n = 23) fuses with a human egg cell (n = 23), what is the chromosome number of the resulting zygote?

Accepted Answer

2n = 46

Question 11

Which of the following statements about homologous chromosomes is correct?

Accepted Answer

They carry genes controlling the same inherited characters.

Question 12

In most fungi and some protists, which stage is the only diploid stage in their life cycle?

Accepted Answer

Single-celled zygote

Question 13

Which process is responsible for maintaining the chromosome number across generations in sexually reproducing organisms?

Accepted Answer

Meiosis and fertilization

Question 14

What is the evolutionary significance of genetic variation produced in sexual life cycles?

Accepted Answer

It leads to the accumulation of genetic variations favored by the environment through natural selection.

Question 15

Which of the following best explains why offspring resemble their parents but are not identical to them?

Accepted Answer

Offspring inherit a unique combination of genes from both parents due to meiosis and fertilization.

Question 16

Which of the following is true regarding the chromosome number in gametes and somatic cells in humans?

Accepted Answer

Gametes have 23 chromosomes, somatic cells have 46.

Question 17

Which event occurs during metaphase I of meiosis that contributes to genetic variation?

Accepted Answer

Homologous pairs align randomly at the metaphase plate, leading to independent assortment.

Question 18

A mutation occurs in a gene. What is the immediate result of this mutation in terms of genetic diversity?

Accepted Answer

It creates a new allele of the gene.

Question 19

Which of the following best describes the outcome of meiosis II?

Accepted Answer

Sister chromatids are separated, resulting in four haploid cells.

Question 20

In a real-world scenario, why might a population of asexually reproducing organisms, such as bdelloid rotifers, still exhibit genetic diversity?

Accepted Answer

They incorporate foreign DNA from the environment.

Meiosis and Sexual Life Cycles: Study Notes for General Biology

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