Question

In a type of apomixis known as adventive embryony, embryos develop directly from the

• A. nucellus or integuments
• B. zygote
• C. synergids or antipodals in an embryo sac
• D. accessory embryo sacs in the ovule.

Answer 1

Answer: (A)

nucellus or integuments

Answer 2

Normal type of sexual reproduction having two regular features, i.e., meiosis and fertilization, is called amphimixis. But in some plants, this normal sexual reproduction (amphimixis) is replaced by some abnormal type of sexual reproduction called apomixis. Apomixis may be defined as, 'abnormal kind of sexual reproduction in which egg or other cells associated with egg (synergids, antipodals, etc.) develop into embryo without fertilization and with or without meiosis'. Adventive embryony is a type of apomixis in which development of embryos directly from sporophytic tissues like nucellus and integuments takes place, e.g., in Citrus, mango, etc.