IB BIO TOPIC 2.5 : CELL DIVISION

Question 1

What are the 5 phases of cell division ?

Answer 1

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1. Interphase
2. Prophase
3. Metaphase
4. Anaphase
5. telophase

Question 2

What are the 3 steps in Interphase ?

Answer 2

1. G1 : Growth, protein synthesis, increase in the number of mitochondria and/chloroplasts
2. S : DNA replication
3. G2 : Growth,protein synthesis, preparation for mitosis/cytokinesis.

Question 3

What is mitosis in 2 words ?

Answer 3

nuclear division

Question 4

What is cytokinesis in 2 words ?

Answer 4

cellular division

Question 5

What are tumours the product of ?

Answer 5

uncontrolled cell division that occur in any organ or tissue.

Question 6

What is interphase in a sentence ?

Answer 6

Active period in the life of a cell when many metabolic reactions occur, including protein synthesis, DNA replication and an increase in the number of mitochondria and/or chloroplasts.

Question 7

What are the 5 main steps in Prophase ?

Answer 7

1. Chromosomes condense by supercoiling becoming visible.
2. Centrioles move to opposite poles
3. nucleolus disappears
4. Nuclear membrane disappears
5. Microtubular spindle apparatus form at each poles.

Question 8

What are the 2 main steps in Metaphase ?

Answer 8

1. Spindle microtubules attach to chromosomes centromeres

2. Chromosomes move to the equator

Question 9

What are the 2 steps in Anaphase ?

Answer 9

1. Centromeres split as spindle microtubules pull chromatids to opposite poles (after centromeres split sister chromatids become sister chromosomes)
2. Sister chromosomes move to opposite poles as microtubules shorten.

Question 10

What are the 6 steps in Telophase ?

Answer 10

1. Sister chromosomes have arrived at poles
2. Spindle disappears
3. Centrioles replicate
4. Nuclear membrane becomes visible
5. Nucleolus becomes visible
6. Chromosomes decondense becoming chromatin

Question 11

How does mitosis produce 2 genetically identical nuclei ?

Answer 11

1. DNA replication during S phase of interphase produces 2 identical copies of DNA.
2. Identical sets of DNA are attached to each other as sister chromatids of each of the cell’s chromosomes.
3. Mitosis segregates the two chromatids of each chromosome to opposite poles, forming two identical nuclei, each with one complete copy of the original DNA.
4. Cytokinesis separates the two daughter nuclei into identical daughter cells.

Question 12

What 4 other processes involve mitosis ?

Answer 12

1. Growth
2. Embryonic development
3. Tissue repair
4. Asexual reproduction

Question 13

Give a complete definition of Mitosis

Answer 13

Mitosis is the duplication and division of a eukaryotic cell’s nucleus and nuclear material (DNA). The stages of mitosis are : Interphase, Prophase, Metaphase, Anaphase and Telophase.

Question 14

Recap of Interphase

Answer 14

The phase of a cell’s life where DNA is repicated

Question 15

Recap of Prophase

Answer 15

The phase in mitosis in which the duplicated chromosomes condense, the nuclear envelope dissolves and centrioles divide and move to opposite ends of the cell.

Question 16

Recap of Metaphase

Answer 16

The phase in mitosis in which chromosomes line up at the equator (central plane of the cell).

Question 17

Recap of Anaphase

Answer 17

The phase in mitosis in which chromosomes begin to separate.

Question 18

Recap of telophase

Answer 18

The last phase, when the chromosomes migrate to opposite ends of the cell, two nuclear envelopes form, and the chromosomes uncoil.