Mitosis

Question 1

describe the daughter cells produced by mitosis (3)

Answer 1

two daughter cells
same number of chromosomes as the parent cell and each other
all genetically the same except in the rare event of a mutation

Question 2

mitotic index equation

Answer 2

= number of cells undergoing mitosis / total number of cells

Question 3

what happens if mitosis is not controlled

Answer 3

can lead to mutations and cancers, many cancer treatments are directed to controlling rate of cell divisions

Question 4

5 phases of mitosis

Answer 4

interphase
prophase
metaphase
anaphase
telophase

Question 5

interphase (2)

Answer 5

Replication of DNA so amount of chromatin doubles and spindle proteins synthesised

Question 6

prophase (3)

Answer 6

Chromosomes become visible as they shorten and thicken
Centrioles move to opposite poles of the cell where spindle fibres develop
Nuclear envelope breaks down leaving chromosomes free in the cytoplasm

Question 7

metaphase

Answer 7

Spindle fibres attach to the centromere of every chromosome so they line up across the equator of the spindle

Question 8

anaphase (2)

Answer 8

centromere splits so sister chromatids divide

spindle fibres contract and pull chromatids to opposite poles

Question 9

telophase (3)

Answer 9

Chromosomes group together at each pole and a nuclear envelop forms around each group
chromosomes uncoil to form chromatin
cytoplasm splits (cytokinesis)

Question 10

binary fission in prokaryotic cells (2)

Answer 10

1. Replication of DNA and circular plasmids

2. Division of cytoplasm gives two daughter cells, each with one circular DNA and variable copies of plasmids