Genetics : Genetics

Study concepts, example questions & explanations for Genetics

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Example Questions

Example Question #11 : Genetics

If a human somatic cell contains 46 chromosomes, how many chromosomes are contained in a human gamete?

Possible Answers:

46 chromosomes

92 chromosomes

0 chromosomes

23 chromosomes

Correct answer:

23 chromosomes

Explanation:

While somatic cells in humans are diploid and contain 46 chromosomes total (or 23 pairs), gamete cells are haploid and contain 23 chromosomes. When a gamete, such as an egg, combines with a sperm during fertilization, two haploid cells combined to make one diploid cell called a zygote. This zygote undergoes meiosis and produces the offspring's gametes. 

Example Question #12 : Cell Division

Division of the cytoplasm during cell division is called __________.

Possible Answers:

mitosis

meiosis

cytokinesis

fertilization

Correct answer:

cytokinesis

Explanation:

By definition, cytokinesis is the act of cytoplasmic division during cell division, be it during mitosis or meiosis. In the case of mitosis, one somatic cell that has replicated its DNA divides into two daughter cells that genetically identical to the parent cell. 

Example Question #12 : Genetics

What is the correct order of mitosis?

I. Anaphase

II. Prophase

III. Metaphase

IV. Telophase

V. Cytokinesis

Possible Answers:

II , III, I, IV, V

IV, II, III, V, I

V, IV, III, II, I

II, I, III, V, IV

I, II, III, IV, V

Correct answer:

II , III, I, IV, V

Explanation:

The correct order is as follows:

Prophase

Metaphase

Anaphase

Telophase

Cytokinesis

Cytokinesis signals the end of mitosis. In this phase, a fiber ring contracts around each daughter cell (thus making two complete daughter cells).

Example Question #13 : Genetics

If a species has a diploid number of 10 chromosomes, how many chromatids would there be in prophase of mitosis?

Possible Answers:

40

15

5

20

10

Correct answer:

20

Explanation:

Diploid means 2n, where n is the number of chromosomes in a particular species. If there are 10 chromosomes, there will be 20 chromatids. For each chromosome there are two chromatids. Since this is before the cells have fully divided, there will be 2 times the number of chromosomes during prophase. Therefore, the answer is 20.

Example Question #14 : Genetics

What binds to CDK's, which activates the CDKs to phosphorylate components of the cell cycle, regulating transcriptions, translation, and differentiation.

Possible Answers:

cyclins

tumor suppressors 

secondary messangers

growth factors

Correct answer:

cyclins

Explanation:

Cyclins combine with CDK to regulate the cell cycle progression, forming active kinases, which phosphorylated the checkpoints. Tumor suppressors can inhibit cyclins and CDK to down regulate growth. Growth factors bind to receptors, which then have their message carried via secondary messangers to transcription factors. Transcription factors may then activtae CDK or cyclins.

Example Question #15 : Genetics

What is the correct order of cell division stages in mitosis?

Possible Answers:

interphase, prophase, metaphase, anaphase, telophase and cytokenesis

metaphase, interphase, telophase, prophase, anaphase, and cytokenesis

 interphase, telophase, metaphase, prophase, anaphase, and cytokenesis

 interphase,cytokenesis, telophase, metaphase, prophase, and anaphase

Correct answer:

interphase, prophase, metaphase, anaphase, telophase and cytokenesis

Explanation:

The correct order is interphase, prophase, metaphase, anaphase, telophase and cytokenesis. The best way to approach this question is to understand what happens in each stage of the process. In interphase, the individual chromosomes line up and copy. In prophase, the chromosomes pair up. In metaphase, the chromosomes line up along the mitotic spindle. In anaphase, the chromatids are are pulled apart on opposite sides of the cell attached to spindle fibers. In the last two stages, telophase and cytokenesis, the cell pinches at the middle and splits off to produce two daughter cells. If you know what happens at each stage, you will be able to put together the order in which they happen

Example Question #17 : Cell Division

At which stage is the last checkpoint before cell division begins?

Possible Answers:

G2

S

G1

G0

Correct answer:

G2

Explanation:

G2, or Gap 2 phase, is the third and last subphase of interphase, preceding mitosis. S phase is the phase in which DNA is duplicated and G1 has the first checkpoint. G0 is the phase where cells do not divide anymore, also known as the resting phase. 

Example Question #16 : Genetics

At what stage of cell division do the chromatids line up in the middle of the cell?

Possible Answers:

interphase

prophase

telophase

metaphase

Correct answer:

metaphase

Explanation:

Interphase is the first stage of cell division and involves the cell going about its normal business. Prophase is when the chromatin bundle up into chromosomes. Anaphase occurs when the sister chromatids separate. Telophase is when the cell pinches, and cytokenisis is when the cell actually seperates. Metaphase is the stage where the sister chromatids line up in the middle of the cell.

Example Question #17 : Cell Division

During cell division, at what phase does the cell separate into two?

Possible Answers:

Anaphase

prophase

Metaphase

ctyokinesis

Correct answer:

ctyokinesis

Explanation:

Cytokinesis is the last processes of cell replication and division and consists of the cell membrane dividing into two.

Example Question #17 : Genetics

When undergoing Meiosis, at what stages should the dividing cell(s) have 2n?

Possible Answers:

prophase I, prophase II, metaphase I, and metaphase II

metaphase I and metaphase II

anaphase I and anaphase II

prophase II, metaphase II, and anaphase II

Correct answer:

prophase II, metaphase II, and anaphase II

Explanation:

During Meiosis, the cell starts with 2n in interphase, then duplicates its DNA to have 4n throughout prophase I, metaphase I, and anaphase I. The cell then splits in two during telophase/cytokinesis, and there are 2n during prophase II, metaphase II, and anaphase II. The end product after telophase II is 1n.

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