Question

Assertion : The method of development of embryo sac from a single functional megaspore is termed as monosporic development.
Reason: In monosporic (Polygonum) type of embryo sac development, usually the megaspore which is situated towards micropylar end remains functional.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (C)

In monosporic (Polygonum) type of development of embryo sac, only one megaspore situated towards chalazal end remains functional. The remaining three megaspores gradually degenerate and finally disappear. The functional haploid megaspore enlarges in size and by means of three successive mitotic divisions, gives rise to an eight-nucleate embryo sac. This type of embryo sac development occurs in a majority of flowering plants and the common example is Polygonum.