Biology · May / June 2020 · Paper 41 · Question 3

any three from:

blue at time 0 indicates no glucose present ;

ensures that no glucose on outer surface of dialysis tubing / in water, as a result of an error ;

green / yellow / red, indicates presence of glucose ;

glucose, diffuses / moves, out of dialysis tubing / into water ;

(movement is) down the concentration gradient / high to low concentration ;

dialysis tubing is permeable to glucose ;

AVP ;

idea that (Benedict’s solution) changes colour quicker / gives more intense colour / AW ;

A are microvilli ;

function: allow movement of substances into the cell / increase surface area for absorption by diffusion OR active transport / have proteins in the membrane for active transport ;

B is the (rough) endoplasmic reticulum / (R)ER ;

function: site of protein synthesis / modify proteins / assemble amino acids in a specific sequence to make (named) protein ;

C is a mitochondrion ;

function: aerobic respiration / provides energy for (named) cell process(es) ;

chloride ;

any four from:

loss of water ;

by osmosis / down water potential gradient ;

diarrhoea ;

dehydration ;

loss of other, (named) ions / salt(s) ;

AVP ;