Question
Biology Question on Sexual Reproduction
Mesogamy is
fusion of male & female gametes
fusion of physiologically similar & morphologically different gametes
entry of pollen tube through integuments
none of the above
entry of pollen tube through integuments
Solution
In seed plants fertilization is siphonogamous because it occurs with the help of pollen tube. The pollen tube pierces through stigmatic papilla into tissue of style. When pollen tube reaches in ovaiy region, it may enter into the ovule in three different ways. The process of entry of pollen tube through integuments or funiculus is called mesogamy. It occurs in Cucurbita and Pistacia. The process of entry of pollen tube into ovary through micropyle is called porogamy, e.g. most angiosperms and when pollen tube enters through chalaza it is called chalazogamy, e.g. Betula.