Biology · May / June 2023 · Paper 42 · Question 6

either (all) roots have grown, downwards / with gravity (no matter which way they were facing at the start)

or roots show positive, gravitropism / geotropism

and

either (all) shoots have grown, upwards / in opposite direction to gravity (no matter which way they were facing at the start) or shoots show negative, gravitropism / geotropism ;

gravitropism ;

any five from:

(auxin) made in / released from, (shoot) tip ;

(auxin) moves by diffusion ;

(auxin) stimulates cell elongation ;

in B / Petri dish 1:

(auxin) has a higher concentration of auxin on the lower surface (of the shoot) ; ora

(auxin stimulates cell) elongation more on lower side of the shoot ; ora

shoot grows away from the pull of gravity / AW ;

in E / Petri dish 2:

(auxin is) equally distributed (in the shoot) ;

(auxin stimulates cell) elongation equally on, both / all, sides of the shoot ;

(shoots grow neither up or down / shoot grows straight) because the effect of gravity is, constantly changing / countered by rotating (the Petri dish)

example of an appropriate environment condition ;

any two from:

(oxygen) aerobic respiration ;

(water) used in (named) cell process ;

(water) is a solvent / AW ;

(water) used for turgor ;

AVP ;