Why it is important to emasculate and bag wheat, oats and groundnut flowers before a cross is made by using another desirable plant.

There are no options in this question but it can be answered using general knowledge. The answer is:

In order to prevent self-pollination or natural cross-pollination of the wheat, oats or groundnut flowers.

Explanation:

The flowers of wheat, oat and groundnut plants have something in common, which is the fact that they are all bisexual flowers i.e. flowers that have both male and female reproductive parts. Hence, they tend to undergo self-pollination i.e. transfer of pollen to female reproductive part on the same flower.

To prevent this from occuring when a desirable trait is wanted during crop breeding procedures, a process called EMASCULATION is carried out. Emasculation is the process whereby the stamen (male flower) or pollen of a plant is removed without destroying the female part of the flower. This is done in order to discourage self-pollination in plants with a bisexual flower.

Also, after emasculation, the flowers are bagged in order to prevent natural cross-pollination i.e. to prevent pollens from other plant from being transferred to the stigma of the desired plants in random manner.

Hence, emasculation and bagging is important to make sure the desired plants are still viable for the crop breeding procedure.

the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.