Embryo sac is to ovule as _______ is to an anther.
(a) Stamen
(b) filament
(c) pollen grain
(d) androecium
Embryo sac is the female gametophyte which is an an oval structure in the nucellus of the ovule of flowering plants and the ovule is the megasporangium. Similarly, the Pollen grain is the male gametophyte and the anther microsporangium.
Birds and bats have homologous limbs because they are both ultimately derived from terrestrial tetrapods, but their flight mechanisms are only analogous, so their wings are examples of functional convergence.
