Cell division topic 1.6

Question 1

Cell cycle

Answer 1

The cell cycle is an ordered set of events that culminates in cell division

Question 2

Interphase

Answer 2

An active phase of the cell cycle where many metabolic reactions occur
* Consists of G1, S and G2 stages

Question 3

M phase

Answer 3

The period of a cell cycle in which the cell and contents divide
* Consists of mitosis (P, M, A, T) and cytokinesis

Question 4

Normal metabolism cannot occur during M phase, so key
events must occur during interphase to prepare for division:

Answer 4

• DNA replication (during S phase)
• Organelle duplication
• Cell growth
• Transcription / translation
• Obtaining nutrients
• Respiration (cellular)

Question 5

Supercoiling

Answer 5

During mitosis, chromatin condenses via supercoiling to
become tightly packed chromosomes

Question 6

Mitosis

Answer 6

Mitosis is the division of a diploid nucleus
into two genetically identical diploid nuclei

Question 7

This process of cell cloning is needed for
many important processes:

Answer 7

• Tissue repair
• Organism growth
• Asexual reproduction
• Development of embryos

Question 8

Cytokinesis

Answer 8

Cytokinesis is the process of cytoplasm division, whereby a cell splits in two

Question 9

Cytokinesis in animals

Answer 9

Microtubules form a concentric ring and
contract towards the centre (centripetal)

Question 10

Cytokinesis in plants

Answer 10

Vesicles form at the cell centre and fuse
outwards to form a cell plate (centrifugal)

Question 11

Mitotic Index

Answer 11

The mitotic index is a measure of the proliferative
status of a cell population (i.e. number of dividing cells)

Question 12

Formula for Mitotic index

Answer 12

Mitotic index = Cells in mitosis/Total number of cells