mitosis and the cell cycle

Question 1

what does mitosis produce

Answer 1

2 genetically identical daughter cells

Question 2

what does meiosis produce

Answer 2

4 daughter cells with half the number of chromosomes

Question 3

order of cell cycle

Answer 3

interphase
prophase
metaphase
anaphase
telophase
cytokinesis

Question 4

what happens during prophase

Answer 4

chromatin condenses
spindle fibres start to develop
nucleolus disappears
nuclear envelope breaks down

Question 5

what happens during metaphase

Answer 5

chromosomes pulled along spindle apparatus and arranged across equator of the cell

Question 6

what happens during anaphase

Answer 6

centromeres divide in 2
spindle fibres pull chromatids to opposite poles of the cell

Question 7

what happens during telophase

Answer 7

chromosomes return to chromatin state
spindle fibres disintegrate
nuclear envelope + nucleolus reforms

Question 8

what happens during cytokinesis

Answer 8

cytoplasm and cell membrane divides to form 2 daughter celld

Question 9

what happens during interphase

Answer 9

synthesis of DNA
synthesis of protein
synthesis of ATP
growth of cytoplasm and organelles

Question 10

what happens during binary fission

Answer 10

DNA replicates
cell membrane grows and pinches inwards, dividing cytoplasm
new cell wall forms between
produces 2 daughter cells

Question 11

what is the process of replication of viruses

Answer 11

attach to host cell
inject nucleic acid into cell
this instructs host cell to produce viral components, nucleic acid, enzymes and proteins
new viruses are made inside host cell
host cell bursts to release new viruses

Question 12

what is it called when the host cell bursts

Answer 12

lysis

Question 13

what causes cancer

Answer 13

mutation in a gene that controls the cell cycle causing damage to genes leading to the development of a tumour

Question 14

what can the rate of mitosis be affected by

Answer 14

the environment of the cell
growth factors
proto oncogenes
tumour suppressor factors

Question 15

what can a mutation to a proto oncogene / tumour suppressor factors cause

Answer 15

uncontrolled mitosis

Question 16

what are the features of a malignant tumour

Answer 16

very uncontrolled division
less compact
more likely to be life threatening
can be carried by the blood steam or lymphatic system to invade other tissues

Question 17

what are the features of a benign tumour

Answer 17

do not spread from point of origin
do not cause cancer
less life threatening

Question 18

three treatments for cancer

Answer 18

surgery - removal of tumour
radiotherapy
chemotherapy

Question 19

what is radiotherapy

Answer 19

radiation damages DNA and causes cells to kill themselves

Question 20

what is chemotherapy

Answer 20

drugs used to treat cancer

Question 21

how does chemotherapy work (2 ways)

Answer 21

• prevents DNA from replicating
• inhibits the metaphase stage of mitosis by interfering with spindle formation

Question 22

what is the issue with cancer drugs

Answer 22

they also disrupt cell cycle of normal cells

Question 23

why does chemotherapy cause hair loss

Answer 23

drugs are more effective against rapidly dividing cells - hair cells are rapidly dividing