Question 1

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

Accepted Answer

Asexual reproduction involves a single parent and produces genetically identical offspring, while sexual reproduction involves two parents and produces genetically diverse offspring.

Question 2

What is the correct definition of a gene's locus?

Accepted Answer

The specific position of a gene along a chromosome.

Question 3

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

Accepted Answer

$$46$$, diploid

Question 4

Which of the following statements about homologous chromosomes is correct?

Accepted Answer

They carry genes controlling the same inherited characters but may have different alleles.

Question 5

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 6

If a human cell undergoes meiosis, how many genetically distinct gametes can be produced due to independent assortment alone? Use $$n = 23$$ for humans.

Accepted Answer

$$2^{23}$$

Question 7

Which of the following is NOT a mechanism that contributes to genetic variation in sexually reproducing organisms?

Accepted Answer

Replication of DNA during interphase

Question 8

A diploid cell with $$2n = 8$$ undergoes meiosis. How many chromosomes will each resulting gamete contain?

Accepted Answer

$$4$$

Question 9

Which event is unique to meiosis and does NOT occur in mitosis?

Accepted Answer

Synapsis and crossing over between homologous chromosomes

Question 10

A geneticist observes a karyotype with 47 chromosomes, including three copies of chromosome 21. What is the most likely explanation for this observation?

Accepted Answer

Nondisjunction occurred during meiosis, resulting in trisomy 21 (Down syndrome).

Question 11

Which of the following best explains why offspring produced by sexual reproduction are genetically unique?

Accepted Answer

Offspring inherit unique combinations of alleles due to independent assortment, crossing over, and random fertilization.

Question 12

Which phase of meiosis is responsible for reducing the chromosome number from diploid to haploid?

Accepted Answer

Anaphase I

Question 13

In which type of organism does the multicellular stage exist in both haploid and diploid forms, as shown in the alternation of generations?

Accepted Answer

Plants and some algae

Question 14

Which of the following statements about gametes is correct?

Accepted Answer

Gametes are haploid cells produced by meiosis.

Question 15

A scientist observes that after meiosis, four daughter cells are produced, each with a different combination of alleles. Which process most directly explains this observation?

Accepted Answer

Crossing over during prophase I

Question 16

Which of the following equations correctly represents the number of possible chromosome combinations due to independent assortment in a species with a haploid number $$n$$?

Accepted Answer

$$2^n$$

Question 17

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

Accepted Answer

Sister chromatids are separated into four genetically distinct haploid cells.

Question 18

Why does no chromosome replication occur between the end of meiosis I and the beginning of meiosis II?

Accepted Answer

Because the chromosomes are already replicated prior to meiosis I.

Question 19

Which of the following is a correct comparison between mitosis and meiosis?

Accepted Answer

Mitosis conserves chromosome number, while meiosis reduces it by half.

Question 20

A mutation occurs in a gene during DNA replication in a gamete. What is the most likely consequence for the offspring?

Accepted Answer

The mutation may be inherited by the offspring and contribute to genetic variation.

Meiosis and Sexual Life Cycles: Study Notes for General Biology

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