Q: The mitotic index is calculated as the percentage of cells in mitosis. If a sample of 1000 cells contains 200 cells in mitosis, what is the mitotic index?

$$ \frac{200}{1000} \times 100 = 20\% $$

Question 1

Which phase of the cell cycle is characterized by DNA synthesis, and what is the main event that occurs during this phase?

Accepted Answer

S phase; DNA replication occurs

Question 2

A scientist observes a cell with a visible cleavage furrow under a microscope. Which stage of the cell cycle is this cell most likely in?

Accepted Answer

Cytokinesis

Question 3

The mitotic index is calculated as the percentage of cells in mitosis. If a sample of 1000 cells contains 200 cells in mitosis, what is the mitotic index?

Accepted Answer

$$ \frac{200}{1000} 	imes 100 = 20\% $$

Question 4

Which checkpoint in the cell cycle ensures that all chromosomes are properly attached to the spindle before proceeding?

Accepted Answer

Metaphase-Anaphase transition

Question 5

If a cell cannot repair DNA damage, which process is most likely to occur?

Accepted Answer

The cell will enter apoptosis

Question 6

During which stage of mitosis do sister chromatids separate and move toward opposite poles?

Accepted Answer

Anaphase

Question 7

What is the primary function of the kinetochore during mitosis?

Accepted Answer

To attach spindle microtubules to the centromere

Question 8

A diploid organism has two copies of each chromosome. What is the main advantage of being diploid?

Accepted Answer

It provides a backup copy of each gene in case one is damaged

Question 9

Which of the following best describes the law of independent assortment?

Accepted Answer

Alleles of each gene separate independently during gamete formation

Question 10

A cat with genotype Ss (long hair, S is dominant) mates with a cat with genotype ss (short hair). What is the probability that their offspring will have long hair?

Accepted Answer

$$ \frac{1}{2} $$

Question 11

If crossing over between genes A and B is 10%, between B and C is 25%, and between A and C is 15%, what is the correct order of these genes on the chromosome?

Accepted Answer

A-B-C

Question 12

Which of the following is NOT a function of the G1 phase in the cell cycle?

Accepted Answer

DNA synthesis

Question 13

In a population of cells, 400 have x amount of DNA, 250 have 2x, and 150 have amounts between x and 2x. Which phase are the 150 cells most likely in?

Accepted Answer

S phase

Question 14

Which process results in the formation of genetically unique gametes due to crossing over?

Accepted Answer

Meiosis

Question 15

What is the main difference between asexual and sexual reproduction?

Accepted Answer

Asexual reproduction produces genetically identical offspring, while sexual reproduction produces genetically diverse offspring

Question 16

Which of the following best describes terminal differentiation?

Accepted Answer

A cell permanently exits the cell cycle and will not divide again

Question 17

If a cell is observed with chromosomes aligned at the metaphase plate, which stage of mitosis is it in?

Accepted Answer

Metaphase

Question 18

Which of the following is a real-world application of the mitotic index?

Accepted Answer

Screening for cancer by measuring how rapidly cells are dividing

Question 19

Which of the following statements about polyploid organisms is correct?

Accepted Answer

They have more than two sets of chromosomes

Question 20

Which event occurs during anaphase B of mitosis?

Accepted Answer

Spindle poles move apart, increasing the distance between them

Cell Cycle, Mitosis, Meiosis, and Mendelian Genetics: Study Notes

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