Mitosis As

Question 1

define mitosis

Answer 1

making two identical daughter cells

Question 2

what is mitosis for

Answer 2

growth, differentiation and repair

Question 3

what are the phases of mitosis

Answer 3

interphase
prophase
metaphase
anaphase
telophase

Question 4

what are the 3 different parts of interphase

Answer 4

G1 phase
synthesis phase (S)
G2 phase

Question 5

what happens during G1 phase

Answer 5

organelles synthesised, cell grows

Question 6

what happens during synthesis phase

Answer 6

DNA replicates
amount of DNA doubles at this point
chromosome number stays the same

Question 7

what happens during G2 phase

Answer 7

organelles grow

energy stores increase

Question 8

what does it mean if a cell is only in interphase for a short amount of time

Answer 8

it replicates quickly

Question 9

what happens during prophase

Answer 9

chromosomes condense and become visible
chromosomes appear as chromatids joined by the centromere
nuclear disintegrates
nucleolus disappears

Question 10

what happens during metaphase

Answer 10

spindle formed / chromosome / centromere / chromatids attaches to spindle by their centromeres
chromosomes line up at the centre of the equator of the cell

Question 11

what happens during anaphase

Answer 11

centromere splits
sister chromotids separate
to opposite poles of the cell

Question 12

what happens during telophase

Answer 12

nuclear envelope reforms
spindle disintegrates
chromosome uncoils / becomes thinner

Question 13

how do prokaryotes divide

Answer 13

binary fission

Question 14

process of binary fission

Answer 14

circular DNA replicates and both copies attach to the cell membrane
plasmids replicate
cell membrane grows between two DNA molecules
the cell membrane pinches inward between two DNA molecules, dividing the cytoplasm
a new cell wall forms between the two DNA molecules

Question 15

why do viruses do viral replication

Answer 15

they are non-living so cannot undergo cell division

Question 16

process of viral replication

Answer 16

attaches to the host cell with attachment proteins on the surface
inject nucleic acid into the host cell
the nucleic acid is combined with the host cell’s DNA
starts producing viral components
these are assembled into new proteins

Question 17

define cancer

Answer 17

uncontrolled cell division

Question 18

what causes cancer

Answer 18

genes that regulate mitosis become damaged

Question 19

how to treat cancers

Answer 19

drugs which slow/stop cell division by stopping DNA replication or spindles from being made

Question 20

what is the role of spindles in mitosis

Answer 20

to pull chromatids apart

for the centromere to attach to

Question 21

why are roots tips examined under microscopes

Answer 21

this is where mitosis can be shown to be happening

Question 22

why do you press down on root tip

Answer 22

so it spreads out to be thin enough for light to pass through

Question 23

why do you examine lots of cells to find the mitotic index

Answer 23

ensure a representative sample

Question 24

why do you do repeated countings when finding a mitotic index

Answer 24

to ensure the figures are correct