Question 1

Which of the following best explains why garlic root tips are commonly used to study mitosis in laboratory settings?

Accepted Answer

They have a high rate of cell division, making it easier to observe all stages of mitosis.

Question 2

Colchicine is used in mitosis studies because it inhibits microtubule polymerization. What is the direct cellular effect of this inhibition?

Accepted Answer

Cells are arrested at metaphase because spindle fibers cannot form.

Question 3

A student prepares a garlic root tip squash and observes many cells with condensed chromosomes aligned at the cell's equator, but very few cells in later stages. What is the most likely explanation if colchicine was used?

Accepted Answer

Colchicine prevents progression past metaphase by inhibiting spindle formation.

Question 4

Which of the following best distinguishes between mitosis and meiosis in terms of chromosome number in the resulting cells?

Accepted Answer

Mitosis produces two diploid cells; meiosis produces four haploid cells.

Question 5

During the preparation of a garlic root tip squash, why is it important to use a stain such as aceto-orcein?

Accepted Answer

It binds to DNA, making chromosomes visible under the microscope.

Question 6

A grasshopper spermatocyte undergoes meiosis. If the diploid chromosome number is 24, how many chromosomes will each sperm cell contain after meiosis is complete?

Accepted Answer

$$12$$

Question 7

Which of the following is a unique feature of prophase I of meiosis that does not occur in prophase of mitosis?

Accepted Answer

Homologous chromosomes pair and crossing over occurs.

Question 8

In a laboratory experiment, a student observes a cell with chromosomes lined up in the center, but the chromosomes are in pairs of homologs rather than single file. Which stage and process is being observed?

Accepted Answer

Metaphase I of meiosis

Question 9

Which of the following best describes the role of the centromere during mitosis?

Accepted Answer

It is the region where sister chromatids are joined and where spindle fibers attach.

Question 10

A scientist treats animal cells with colchicine and observes the effects. Which of the following would most likely be observed under the microscope?

Accepted Answer

Cells with duplicated chromosomes arrested at metaphase, unable to proceed to anaphase.

Question 11

Which of the following equations correctly represents the change in chromosome number during meiosis in humans, starting from a diploid cell?

Accepted Answer

$$2n \rightarrow n$$

Question 12

Why is it necessary to macerate the garlic root tip during slide preparation?

Accepted Answer

To separate the cells, making it easier to observe individual stages of mitosis.

Question 13

Which of the following best describes cytokinesis in plant cells compared to animal cells?

Accepted Answer

Plant cells form a cell plate, while animal cells form a cleavage furrow.

Question 14

A student is asked to compare metaphase of mitosis and metaphase I of meiosis. Which statement is correct?

Accepted Answer

In mitosis, individual chromosomes align at the equator; in meiosis I, homologous chromosome pairs align at the equator.

Question 15

If a mutation prevents the formation of spindle fibers during mitosis, which stage will cells most likely be unable to complete?

Accepted Answer

Anaphase

Question 16

Which of the following is a real-world application of colchicine's ability to inhibit mitosis?

Accepted Answer

It is used to treat gout by reducing inflammation caused by uric acid crystals.

Question 17

During spermatogenesis in grasshoppers, what is the relationship between ploidy and the resulting sperm cells?

Accepted Answer

Sperm cells are haploid, containing half the chromosome number of the original cell.

Question 18

Which of the following best explains why crossing over during meiosis is important for evolution?

Accepted Answer

It increases genetic variation by exchanging genetic material between homologous chromosomes.

Question 19

A cell is observed under a microscope with chromosomes that appear as two identical sister chromatids joined at the centromere. Which stage is this cell most likely in?

Accepted Answer

Metaphase

Question 20

Which of the following steps is essential to prevent the garlic root tip squash from drying out during preparation?

Accepted Answer

Ensuring the root tip remains covered with stain or solution throughout the process.

Cell Division and Genetics Laboratory: Mitosis, Meiosis, and Human Inheritance

Guida di studio - Domande di pratica

Study guide - Flashcard