Question

Mesogamy is

• A. fusion of male & female gametes
• B. fusion of physiologically similar & morphologically different gametes
• C. entry of pollen tube through integuments
• D. none of the above

Answer 1

Answer: (C)

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.