Question

What is the term used for the phenomenon of producing seeds without fertilization?

Answer 1

Hint: Production of seeds without fertilization is apomixis. It is a kind of asexual reproduction, which mimics sexual reproduction. In apomixis, there is no chance of diversity of genes. Though apomixis is an asexual method, it still uses sexual organs of the plant, namely ovary and ovules. Apomixis can be seen in angiosperms and gymnosperms. Paternal apomixis is the replacement of the genetic material of an egg by the genetic material of a pollen.

Complete answer
Apomixis is the formation of a plant from a seed without the process of fertilization. It is very common in higher plants. It is a reference to asexual process. The produced plant is a clone of the female parent plant. Some examples of plants undergoing apomixis are cereals, wheat, Rosaceae, Compositae and Rutaceae.
There are different types of apomixis. They are as follows:
1. Vegetative apomixis
2. Recurrent and non-recurrent apomixis
3. Adventitious embryony
4. Apospory
5. Diplospory
In the natural flow of biological processes, pollination is the initial step in the formation of fruit and seed. Subsequent steps involve cell divisions and fertilization. But, in apomixis, there is no meiosis and fertilization of gametes to form a zygote. Then the entire process is shortened and seed formation occurs.
There are two types of apomixis. They are:
Sporophytic apomixis – Apomixis occurs from diploid sporophyte
Gametophytic apomixis – Apomixis occurs from haploid gametophyte
As apomixis involves the formation of seeds without syngamy, all seeds are genetically similar. Hence, it can be used in vegetative propagation.

Note:
Apomixis is a process of reproduction by special generative tissues, which can be gametophyte or sporophyte. Parthenocarpy is a phenomenon of development of fruits without fertilization of ovules. Polyembryony is a process of forming more than one embryo from a single fertilized ovum. Seed dormancy is a state in which seeds are not allowed to germinate even under favorable environmental conditions for germination.