Practicing Success

Target Exam

CUET

Subject

Biology

Chapter

Sexual Reproduction in Flowering Plants

Question:

Which among the following statements are incorrect :

(A) Artificial hybridisation is one of the major approaches of crop improvement programme.

(B) Only the desired pollen grains are used for pollination and the stigma is protected from contamination (from unwanted pollen).  

(C) Removal of anthers from the flower bud before the anther dehisces is called emasculation. 

(D) Continued cross-pollination result in inbreeding depression.

Choose the correct answer from the given options .

Options:

A,B and C only .

C and D only .

Only  D .

B and D only .

Correct Answer:

Only  D .

Explanation:

The correct answer is Option (3)- Only  D .

Continued cross-pollination result in inbreeding depression.This statement is incorrect. Option - 3

Artificial hybridisation is one of the major approaches of crop improvement programme.

In such crossing experiments it is important to make sure that only the desired pollen grains are used for pollination and the stigma is protected from contamination (from unwanted pollen).

This is achieved by emasculation and bagging techniques. If the female parent bears bisexual flowers, removal of anthers from the flower bud before the anther dehisces using a pair of forceps is necessary. This step is referred to as emasculation.

Emasculated flowers have to be covered with a bag of suitable size, generally made up of butter paper, to prevent contamination of its stigma with unwanted pollen. This process is called bagging.

When the stigma of bagged flower attains receptivity, mature pollen grains collected from anthers of the male parent are dusted on the stigma, and the flowers are rebagged, and the fruits allowed to develop. If the female parent produces unisexual flowers, there is no need for emasculation.

The female flower buds are bagged before the flowers open. When the stigma becomes receptive, pollination is carried out using the desired pollen and the flower rebagged. 

Continued cross-pollination result in inbreeding depression is not correct .Continued self -pollination result in inbreeding depression.