IGCSE Biology Paper-2: Specimen Questions with Answers 200 - 200 of 203

Question 200

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Question

MCQ▾

Development of an egg without fertilization is called

Choices

Choice (4)
a.Parthenogenesis
b.Mutagenesis
c.Gametogenesis
d.Oogenesis

Answer

a.

Explanation

Parthenogenesis

  • Process of development of seeds from unfertilized female gametes. Seeds may be haploid or diploid (Gk. pantheons-virgin, genesis-descent). It is the development of a new individual from a single gamete without fusion with another gamete. In lower plants both, the type of gametes can female gametes show this facility. Depending upon the haploid of the gamete, there are two types of parthenogenesis, diploid and haploid.
  • In haploid parthenogenesis, the embryo sac and its egg are haploid. The egg grows to form haploid embryo. Such embryos do not survive in higher plants but in lower plants, the plant body is haploid embryos has survival value. In diploid parthenogenesis, the embryo sac as well as its egg is diploid. It undergoes parthenogenesis and forms diploid embryo.
  • Diploid parthenogenesis is generally accompanied by failure of meiosis during megasporogenesis as well as direct formation of embryo sac from a Nucellar cell, e. g. , RubusPoa, , apple. In apple, self-pollination promotes diploid parthenogenesis.