Question

Embryo development from nucellus and integument is known as
A. Apospory
B. Apogamy
C. Apomixis
D. Adventive embryony

Answer 1

Hint: The development of embryos from a zygote is called embryogeny.
Nucellus : The parenchymatous mass of tissue enclosed within the integuments and forms the body of ovule. Integument : The one or more protective envelope surrounding the body of ovule.

Complete answer:
Although seeds, in general, are the products of fertilisation, a few flowering plants such as some species of Asteraceae and grasses, have evolved a special mechanism, to produce seeds without fertilisation, called apomixis. It is a form of asexual reproduction that mimics sexual reproduction.
Now let us find the meaning of each and every option :-
Apospory :- when development of embryo occurs without meiosis and without formation of spores is called apospory. Hence this option is not correct.
Apogamy :- the reproduction in gymnosperms in which sporophyte is produced without fusion if gametes is called apogamy. Thus this option is not correct.
Apomixis :- formation of seeds without fertilisation, called apomixis. It is a form of asexual reproduction that mimics sexual reproduction. Thus this option is not correct.
Adventive embryony :- it is also known as saprophytic budding. Embryo arises from diploid saprophytic cells such as nucellus or integuments (other than egg), e.g., Citrus, Opuntia, Mango. Hence this option is correct.

Our required answer is d that is adventive embryony.

Note: Adventive embryogeny is a type of apomixis. Hybrid varieties are preferred by agriculturists because of their higher yield, vigour and resistance to stresses. They have increased crop productivity, e.g., Maize, Tomato, Cauliflower etc. due to adventive embryony.