mitosis + meiosis

Question 1

def homologous chromosomes

Answer 1

1 from mother, 1 from father
cell contains 23 pairs of homologous chromosomes
same length, centromere position, genes

Question 2

g1

Answer 2

cells grow by producing proteins from which cell organelles are produced

Question 3

s

Answer 3

growth of cell continues, dna replication takes place

Question 4

g2

Answer 4

cell growth continues by protein and cell organelle synthesis
energy stores increased

Question 5

m

Answer 5

nuclear division (mitosis/meiosis)
cell division (cytokinesis)

Question 6

def mitosis

Answer 6

nuclear division that produces 2 genetically identical daughter nuclei containing same number of chromosomes as parent nucleus

Question 7

impt of mitosis

Answer 7

growth (inc no of cells)
cell replacement (prod new cells to replace old dead cells)
genetic stability (pass down same type of genetic info to next gen without variations)
asexual reprod (ensures offspring genetically identical to parent)

Question 8

prophase

Answer 8

condensation of chromatin into chromosomes
movement of centrioles to opp poles of nucleus
formation of spindle fibres around centrioles
disintegration of nuclear envelope

Question 9

metaphase

Answer 9

spindle fibres attach to centromeres

chromosomes line up along equatorial plate

Question 10

anaphase

Answer 10

division of each centromere into 2
separation of sister chromatids. each chromatid is now considered 1 chromosome
spindle fibres contract and pull sister chromatids apart
sister chromatids move twds opp poles of cell

Question 11

telophase

Answer 11

chromosomes arrive at opp ends of cell
uncondensation of chromosomes to chromatin
disintegration of spindle fibres
formation of nuclear membrane around each set of chromosomes at 2 poles to form 2 daughter nuclei

Question 12

cytokinesis in animals

Answer 12

formation of cleavage furrow in cell membrane

cell membranes in furrow joins up and completely separate 2 daughter nuclei

Question 13

cytokinesis in plants

Answer 13

deposition of golgi vesicles along equatorial plate

vesicles merge to form a cell plate and completely separate 2 daughter nuclei

Question 14

def uncontrolled mitosis

Answer 14

when dna of cells become damaged they lose their ability to control their rate of cell division and start to divide repeatedly without regulation causing cancer

Question 15

benign

Answer 15

only grow locally, cannot spread by invasion/metastasis

Question 16

malignant

Answer 16

cells invade neighbouring tissues, enter blood vessels, metastasis to diff sites

Question 17

def metastasis

Answer 17

process by which tumour cell leaves primary tumour, travels to distant site + establishes sec tumour