Question

Mitosis & Meiosis Comprehensive Reading Activity
All living organisms grow, repair damage, and reproduce through a process called cell
division. There are two main types of cell division in most organisms: mitosis and meiosis.
Although both involve the splitting of cells, they serve different purposes and include
different steps.
Interphase: The Preparation Stage
Before either mitosis or meiosis begins, the cell enters a stage called interphase. During
interphase, the cell grows, performs its normal functions, and copies its DNA. The DNA coils
tightly into structures called chromosomes. Each chromosome is made of two identical
halves called sister chromatids, held together at a region known as the centromere.
Structures called centrioles also appear and begin moving to opposite sides of the cell.
Mitosis: Division for Growth & Repair
Mitosis is the type of cell division that produces body cells. It helps organisms grow and
repair damaged tissues. Mitosis results in two identical daughter cells, each containing the
same number of chromosomes as the parent cell.
Mitosis occurs in several phases:
Prophase: Chromosomes become visible, and the nuclear membrane begins to break down.
Prometaphase: The nuclear membrane fully dissolves, and spindle fibers attach to
centromeres.
Metaphase: Chromosomes line up in the middle of the cell.
Anaphase: Sister chromatids separate and move to opposite sides.
Telophase: Two new nuclear membranes form.
After telophase, cytokinesis divides the cytoplasm, forming two identical cells.
Meiosis: Division for Reproduction
Meiosis produces gametes (sex cells). It creates four daughter cells, each genetically
different and containing half the number of chromosomes. Processes like crossing over
increase genetic diversity.
1. What is the main purpose of mitosis?
A. To produce sex cells
B. To create genetic variation
C. To help an organism grow and repair tissues
D. To reduce chromosome number
2. What happens during interphase?
A. The cell divides
B. DNA is copied and the cell grows
C. Chromosomes line up
D. Chromatids separate
3. A chromosome is made of two identical halves called:
A. Centrioles
B. Telomeres
C. Chromatids
D. Cytokines
4. What holds sister chromatids together?
A. Centriole
B. Centromere
C. Cell membrane
D. Spindle fiber
5. During which phase do chromosomes line up in the middle of the cell?
A. Prophase
B. Metaphase
C. Telophase
D. Interphase
6. What occurs during anaphase?
A. Chromosomes become visible
B. Nuclear membrane reforms
C. Sister chromatids separate
D. DNA is copied
7. In which phase does the nuclear membrane break down completely?
A. Prometaphase
B. Telophase
C. Cytokinesis
D. Anaphase
8. What structure helps pull chromosomes apart during mitosis?
A. Nucleus
B. Centriole
C. Ribosome
D. Cell wall
9. What is cytokinesis?
A. DNA replication
B. Nuclear membrane forming
C. Cytoplasm dividing
D. Chromosomes appearing
10. What is the purpose of meiosis?
A. Repairing tissue
B. Producing body cells
C. Creating identical daughter cells
D. Producing gametes
11. Meiosis produces:
A. Two identical cells
B. Four genetically different cells
C. One large cell
D. Four identical cells
12. Why do gametes contain half the number of chromosomes?
A. They divide faster
B. To reduce variation
C. Fertilization restores the full number
D. They don’t have DNA
13. What process creates genetic variety during meiosis?
A. Prophase
B. Crossing over
C. Cytokinesis
D. Interphase
14. Which type of cell division creates genetically identical cells?
A. Meiosis
B. Mitosis
C. Binary fission
D. Budding
15. During which phase do two new nuclei begin to form?
A. Metaphase
B. Anaphase
C. Telophase
D. Interphase

Answer 1

Here are the answers with brief explanations:

1. C — Mitosis helps an organism grow and repair tissues.
2. B — During interphase the cell grows and copies its DNA.
3. C — Each chromosome is made of two identical chromatids.
4. B — Sister chromatids are held together at the centromere.
5. B — In metaphase chromosomes line up at the cell’s equator.
6. C — In anaphase sister chromatids separate and move apart.
7. A — Prometaphase is when the nuclear membrane fully dissolves.
8. B — Centrioles organize the spindle fibers that pull chromosomes apart.
9. C — Cytokinesis is the division of the cytoplasm.
10. D — Meiosis produces gametes (sex cells).
11. B — Meiosis produces four genetically different cells.
12. C — Gametes have half the chromosomes so fertilization restores the full number.
13. B — Crossing over during meiosis creates genetic variation.
14. B — Mitosis creates genetically identical daughter cells.
15. C — In telophase two new nuclei begin to form.