Topic 2 cells: The cell cycle

Question 1

what are the 3 phases of the cell cycle

Answer 1

1. Interphase
2. Mitotic phase
3. Cytokenesis

Question 2

What is involved in the interphase of the cell cycle?

Answer 2

• Growth and development of cell
• Prepares for reproduction-DNA synthesis,etc.

Question 3

What is involved in the mitotic phase of the cell cycle?

Answer 3

Division of nucleus and cell
(4 phases within this)

Question 4

What is involved in cytokinesis?

Answer 4

Division of cell

Question 5

Explain the steps of the prophase (also called the prometaphase)

Answer 5

• Centrioles move to opposite ends
• Nuclear envelope disappears
• Chromosomes appear with centromeres
• Chromosomes move to spindles

Question 6

Key points in the metaphase:

Answer 6

• Chromosomes line up in the centre =>
• Metaphase plate

Question 7

Explain what happens in the anaphase

Answer 7

Sister chromosomes move to opposite ends of spindle

Question 8

Explain what happens in the telophase

Answer 8

• Nuclear envelopes reappear
• Cytokinesis is completed

1. The cell continues to elongate, as free spindle fibres from each centrosome push off each other.
2. Two nuclei begin to form, surrounded by the fragments of the parent’s nuclear envelope.
3. Chromatin becomes less tightly coiled.
4. Cytokinesis begins (division of the cytoplasm)

Question 9

List the 4 phases within the mitotic phase

Answer 9

Prophase/prometaphase
Metaphase
Anaphase
Telophase

Question 10

What are the factors involved in aging

Answer 10

• May be programmed genetically
• Protein cross-links by glucose - diabetes
• Free radical damage - antioxidants
• Cessation of mitosis - Hayflick Limit