Biology · Oct / Nov 2020 · Paper 61 · Question 2

letter on Fig. 2.2

name of flower part

number visible A

stigma

1

B

filament

8

C

sepal

4

;;;

lines: clear single outer line without shading ;

size: X-Y bigger than 35 mm ;

rounded structures inside grain ;

pollen tube top edge with one indentation ;

label to pollen tube ;

line XY 35 ±1 (mm) ;

0.1 mm / 100 µm / 0.01 cm ;;

any two from:

pollen germinated faster / germination rate is higher, in S1 (than S2) (at the start) / AW ; ora

by 60 minutes no difference between (percentage germination) in S1 and S2 ;

(pollen in) S1 stops germinating after 50 minutes / AW ;

only 51% / not all pollen grains, germinated ;

idea that different numbers of pollen were counted on each slide ;

divide the number germinated by the total ;

multiply by 100 ;

y-axis scaled correctly with suitable numbers ;

plot for B and C correct and labelled ;