Question

Perisperm differs from endosperm in
A. Being a haploid tissue.
B. Having no reserve food.
C. Being a diploid tissue.
D. Its formation by fusion of secondary nuclei with several sperms.

Answer 1

Hint: The residual and persistent nucellus is commonly known as perisperm. Seeds in which remnants of nucleus are seen are known as perispermic seeds. Examples of perispermic seed include black pepper and beet. The parenchymatous mass of tissue enclosed within integuments and forms the body of ovule is called nucellus.

Complete answer:
When male gamete fuses with the two polar nuclei in the embryo sac it results in the formation of the primary endosperm nucleus. Endosperm is the product of triple fusion and develops from the central cell of the embryo sac. It is triploid tissue.
Perisperm is usually haploid tissue as it is remnant of nucellus.
Both these tissues serve as reserve food material and provide nourishment to the embryo.
Now let us match these differences with given options:-
Being a haploid tissue :- perisperm is remnant of nucellus is diploid but perisperm develops from nucellus by mitosis so perisperm is also haploid. Endosperm is formed due to the result of triple fusion so is triploid tissue. So they both differ in haploidy. Thus this option is not correct.
Having no reserve food :- Both these tissues serve as reserve food material and provide nourishment to the embryo. Thus this option is not correct.
Being a diploid tissue :- perisperm is diploid as it is formed from nucellus by the equational division mitosis and endosperm is triploid. Thus this option is correct.
Its formation by fusion of secondary nuclei with several sperms. :- perisperm is formed as a result of remnant of nucellus. Thus this option is not correct.

Our required answer is C that is being a diploid tissue.

Note: Endosperm is meant for nourishing the embryo. There are two possibilities.
Endosperm is completely consumed during development of embryo before seed maturation. Such seeds are called ex-albuminous or non-endospermic seeds.
Examples: Pea, Beans, Groundnut
Endosperm persists in mature seeds: Such seeds are called albuminous or endospermic seeds.
Examples: Castor, coconut, rice, wheat, maize, barley.