cell division👯‍♀️👯‍♀️👯‍♀️👯‍♀️

Question 1

how does yeast divide

Answer 1

budding

Question 2

what is bacterial cell wall made of

Answer 2

peptidoglycan

Question 3

difference between xylem cell wall and regular cell wall

Answer 3

• lignified
• thicker
• contains pits

Question 4

how is genetic variation produced

Answer 4

• crossing over in prophase 1
• so chromatids have new combination of alleles
• independent assortment of chromatids in metaphase 1
• homologous chromosomes have different alleles
• produces large number of allele combinations
• mutations
• changes dna base sequence
• random fusion of gametes produces large number of allele combinations as gametes are genetically different

Question 5

what do organisms need oxygen for

Answer 5

aerobic respiration

Question 6

why does meiosis have twice as many stages as mitosis

Answer 6

• to halve number of chromosomes

- separate homologous pairs of chromosomes and separate sister chromatids

Question 7

what are the possible effects of a mutation on the structure and function of a protein

Answer 7

• change to primary, secondary, tertiary structure which changes 3D shape
• protein may not be able to do its function anymore
• protein longer due to insertion or shorter due to deletion
• protein may be unchanged due to silent mutation

Question 8

what feature of the dna molecule is changed due to mutation

Answer 8

sequence of bases

Question 9

outline asexual reproduction in yeast

Answer 9

• mitosis
• bulge on surface of cell
• nucleus moves into bulge
• bulge pinches off

Question 10

why must genetic material replicate before mitosis

Answer 10

• daughter cells are genetically identical

- so both can get full copy

Question 11

function of squamous epithelium

Answer 11

short diffusion pathway

Question 12

where is meristem tissue found

Answer 12

• just behind apex of shoot
• just behind apex of root
• cambium
• bud

Question 13

how does plant cell division differ from animal cell division

Answer 13

• in plants, cell plate/wall forms between new cells
• in plants, cytokinesis starts from middle of cell, in animals, starts from outer edge
• in plants only occurs in meristem, most animal cells can divide
• plants have no centrioles

Question 14

at high temperatures why does active transport stop

Answer 14

-enzymes denatured so ATP cannot be produced for energy

Question 15

what does it mean if a cell spends all its time in G0 or G1

Answer 15

• does not divide
• may be specialised
• may be damage to dna

Question 16

describe what happens in metaphase

Answer 16

• chromosomes align on equator
• chromatids either side of equator
• spindle fibres attach to chromosome