Question

Free nuclear divisions are characteristics of
A. Cellular endosperm
B. Nuclear endosperm
C. Helobial endosperm
D. Both B and C

Answer 1

The product of triple fusion, that is, when male gamete fuses with two polar nuclei and develops from the central cell of embryo sac which is generally a triploid tissue. The cells of this tissue are filled with reserve food materials and are used for the nutrition of the developing embryo. They eliminate waste substances.

Complete answer:
Free nuclear division as the name suggest means when endosperms divide and after every division nucleus divides but cell wall formation do not takes place after each division
On the premise of development, endosperm is of three types:
A.Cellular Endosperm: it's found in 25% angiosperm families, particularly dicotyledons. During the event of cellular kind of endosperm, the first endosperm cell divides by mitotic divisions and every division is followed by cell membrane formation.
B.Nuclear Endosperm: it's more common and located in 56% of angiosperm families. During the event of nuclear form of endosperm, the first endosperm cell divides by free nuclear divisions, and these divisions don't seem to be followed by plasma membrane formation. Thus, the free nuclei remain within the cytoplasm of the embryo sac.
C.Helobial Endosperm: it's present in less number that is in 19% of angiosperm families, particularly monocotyledons. This sort of endosperm is intermediate between cellular and nuclear endosperms and is created thanks to the formation of an outsized micropylar and a little chalazal chamber by a mitotic division within the primary endosperm cell. The nucleus of the chalazal chamber remains undivided or divided by some mitotic divisions whereas the nucleus of the micropylar chamber divides by free nuclear divisions, which are followed by centripetal cell membrane formation.
D.both B and C :- as both nuclear and helobial endosperm undergoes free nuclear division this option is correct.

Our required option is D) Both B and C.

Note: The coconut water present in coconut is the most common and suitable example of free nuclear endosperm as it is made up of many nuclei. The surrounding white kernel of the coconut is an example of cellular endosperm.