Question

What would be the genetic nature of apomictic embryos?

(a) Genetically dissimilar

(b) Genetically similar

(c) Sometimes genetically similar and sometimes genetically dis- similar

(d) Always haploid

Answer 1

Hint: The genetic character of plants developed by apomictic embryos is similar to that of parents so they can be called clones. It does not show any variation.

Complete answer:

Apomictic embryos develop from the process known as apomixis, in this process the embryo is developed without fertilization, which means the male gamete does not fuse with the female gamete. Due to atmospheric conditions or hormones the embryo develops this type of embryo is known as apomictic embryo.

Here we are not able to see the fusion between the gametes, So, the organism which produces it does not show any variation. If there is no variation then it is genetically similar as they are the clones. The genetic character of plants developed by apomictic embryos is similar to that of parents so they can be called clones.

Apomixis take place in at least 33 families of flowering plants, and has developed multiple times from sexual relatives. Apomictic species or individual plants often have a hybrid origin, and are usually polyploidy.

A single genetic change in apomixis affects all the major developmental components, formation of the megagametophyte, parthenogenesis of the egg cell, and endosperm development.

So, the correct answer is ‘Genetically similar’.

Note:

- Apogamy (another type of apomixis) is a related term that has had various meanings over time. In plants with independent gametophytes (notably ferns), the term is still used interchangeably with ‘apomixis’, and both refer to the formation of sporophytes by parthenogenesis (development of an embryo directly from an egg cell without fertilization) of gametophyte cells.

- Male apomixis (parental apomixis) involves replacement of the genetic material of an egg by the genetic material of the pollen.