Question 1

Which of the following best describes the Central Dogma of Molecular Biology?

Accepted Answer

DNA is transcribed into RNA, which is then translated into protein.

Question 2

A mutation in the gene encoding a pigmentation enzyme results in a poorly functional enzyme. What is the most likely consequence at the organismal level?

Accepted Answer

The organism will have a lighter phenotype due to decreased pigment production.

Question 3

Which process increases genetic variation during meiosis?

Accepted Answer

Crossing over during prophase I

Question 4

If a human somatic cell contains 46 chromosomes, how many chromosomes will be present in each gamete after meiosis?

Accepted Answer

23

Question 5

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

Accepted Answer

$$2^n$$

Question 6

A true-breeding plant with purple flowers is crossed with a true-breeding plant with white flowers. All offspring have purple flowers. What does this indicate about the purple allele?

Accepted Answer

It is dominant to the white allele.

Question 7

During which phase of mitosis do chromosomes line up at the metaphase plate?

Accepted Answer

Metaphase

Question 8

What is the main difference between mitosis and meiosis in terms of genetic diversity?

Accepted Answer

Mitosis produces genetically identical cells, while meiosis increases genetic diversity through crossing over and independent assortment.

Question 9

Which of the following best describes a locus?

Accepted Answer

The physical location of a gene on a chromosome

Question 10

A cell with a genotype $$AaBb$$ undergoes meiosis. Assuming independent assortment and no crossing over, what is the probability of producing a gamete with genotype $$ab$$?

Accepted Answer

$$\frac{1}{4}$$

Question 11

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

Accepted Answer

Synapsis and crossing over between homologous chromosomes

Question 12

What is the result of nondisjunction during meiosis?

Accepted Answer

Gametes with an abnormal number of chromosomes

Question 13

Which of the following statements about homologous chromosomes is correct?

Accepted Answer

They have the same genes at the same loci but may have different alleles.

Question 14

In a dihybrid cross between two heterozygous individuals ($$AaBb 	imes AaBb$$), what is the expected phenotypic ratio in the offspring, assuming independent assortment?

Accepted Answer

9:3:3:1

Question 15

Which of the following best explains why cells are considered haploid after meiosis I?

Accepted Answer

Each cell contains only one chromosome from each homologous pair.

Question 16

Which of the following is a real-world application of the Central Dogma of Molecular Biology?

Accepted Answer

Development of mRNA vaccines for diseases such as COVID-19

Question 17

A geneticist is studying a disease caused by a mutation at a specific locus on chromosome 4. What does 'locus' refer to in this context?

Accepted Answer

The physical location of the gene on chromosome 4

Question 18

Which of the following best describes the outcome of binary fission in prokaryotes?

Accepted Answer

Two genetically identical daughter cells

Question 19

During which stage of the cell cycle does DNA replication occur?

Accepted Answer

S phase of interphase

Question 20

A patient is diagnosed with a genetic disorder due to a deficiency in a protein coded by a gene on chromosome 15. Which of the following best explains how this deficiency can arise?

Accepted Answer

A mutation in the gene alters the sequence, leading to a nonfunctional protein.

Genetics Study Guide: Introduction, Chromosomes, Mitosis, and Meiosis

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