WAEC - Biology (1997 - No. 21)
The diagram above represents a?
germinating seed
radicle
shoot showing negative phototropism
zygote
germinating pollen grain
Объяснение
the germination of pollen grains begins by absorption of water and nutrients and the pollen grain produces a tiny pollen tube through the style to the ovary.
The tube cell enlarges and comes out of the pollen grain through one of the germ pores to form a pollen tube.
The tube nucleus descends to the tip of the pollen tube.