The term 'keel' is used for special type of
Sepals
Petals
Stamenstellen
Carpels
B.
Petals
Keel is a special type of petal found in the papilionaceous type of Corolla. Papilionaceous type is a butterfly like the Corolla has one large posterior standard, two lateral wings, two innermost and smaller keels.
A fern prothallus is bisexual. If fertilisation takes place between their gametes than it is known as
cross- fertilisation
self- fertilisation
isogamous
viviparous
Edible part in 'sorosis', a composite fruit, is
cotyledons
endosperm
perianth and peduncle
fleshy thalamus