L4: CELL DIVISON

Question 1

Why do cells divide in our body?

Answer 1

Cells divide for growth and development, to maintain and replace tissues, and to pass on genetic information.

Question 2

What are the main stages of cell division?

Answer 2

The main stages are Interphase and Mitosis/Meiosis

Question 3

What type of cells undergo mitosis?

Answer 3

Cells that make up the body but are not involved in sexual reproduction undergo mitosis.

Question 4

Which cells in the body undergo meiosis?

Answer 4

Meiosis occurs exclusively in cells that produce sperm and eggs.

Question 5

Can you give an example of mitosis in the body?

Answer 5

Skin turnover is an example of mitosis.

Question 6

What happens during mitosis?

Answer 6

A single parent cell divides into two identical daughter cells, each with a full set of DNA and organelles.

Question 7

What are the two main stages of the cell cycle?

Answer 7

The two main stages are Interphase and Mitosis (or cell division).

Question 8

What are the phases of Interphase?

Answer 8

Interphase consists of three phases: G1 (cell growth), S (DNA replication), and G2 (preparation for mitosis).

Question 9

What happens during the G1 phase?

Answer 9

During G1, the cell grows and produces proteins needed for DNA replication in the S phase.

Question 10

What happens during the G2 phase?

Answer 10

In G2, the cell prepares for mitosis by synthesizing proteins required for division.

Question 11

What is chromatin?

Answer 11

Chromatin is DNA wrapped around proteins in the nucleus, which condenses into chromosomes during mitosis.

Question 12

What is a chromosome?

Answer 12

A chromosome is a single strand of DNA that becomes condensed and visible during mitosis.

Question 13

What happens during prophase?

Answer 13

DNA condenses into chromosomes, centrosomes move to opposite poles, and spindle fibers begin to form.

Question 14

What happens during late prophase?

Answer 14

The nuclear envelope dissolves, and spindle fibers attach to chromosomes at the kinetochore.

Question 15

What happens during metaphase?

Answer 15

During metaphase, chromosomes align at the metaphase plate in the center of the cell.

Question 16

What happens during anaphase?

Answer 16

In anaphase, sister chromatids are pulled to opposite poles of the cell, becoming daughter chromosomes.

Question 17

What happens during telophase?

Answer 17

In telophase, chromosomes de-condense, new nuclei form, and the spindle breaks down.

Question 18

What happens during cytokinesis?

Answer 18

Cytokinesis is the final step of cell division, where the cytoplasm splits, and two daughter cells are formed. In animal cells, a cleavage furrow forms.

Question 19

How many chromosomes do humans have?

Answer 19

Humans have 46 chromosomes, which are arranged in 23 pairs

Question 20

Why do we say humans have 23 pairs of chromosomes?

Answer 20

Humans inherit 23 chromosomes from their father and 23 chromosomes from their mother, forming 23 homologous pairs.

Question 21

How are gametes (sperm and egg) different from somatic cells?

Answer 21

Gametes are haploid, meaning they have only 23 chromosomes, half the number of chromosomes in somatic (body) cells.

Question 22

What is meiosis?

Answer 22

Meiosis is the process by which gametes (sperm and eggs) are produced, halving the chromosome number from diploid to haploid.

Question 23

What happens during Meiosis I?

Answer 23

In Meiosis I, homologous chromosomes pair up and are separated into different cells, resulting in haploid daughter cells.

Question 24

What happens during Meiosis II?

Answer 24

Meiosis II is similar to mitosis, where chromatids separate, resulting in four haploid gametes.

Question 25

What is fertilization?

Answer 25

Fertilization is the fusion of a sperm and egg (both haploid), resulting in a zygote with a diploid chromosome number.