Question

In a pollen grain, if T=40%, C=10%, then G=?
A) 40%
B) 10%
C) 91%
D) 20%

Answer 1

Hint:Pollen grains are the male gametes of the plants. They are the microscopic structures that carry the male reproductive cell. Pollen grain contains a hard coat which is made up of sporopollenin substance in order to protect the pollen grain. In order to find the value of G in the question first we have to discuss nitrogenous bases and chargaff’s rule.

Complete answer:
Nitrogenous bases:
>Adenine (A), Thymine (T), Cytosine (C), Uracil (U) and Guanine (G) are the nitrogenous bases.
>Nitrogenous bases are the organic molecules with a nitrogen atom that has the chemical properties of the base.
>The main function of these nitrogenous bases is to bond nucleic acids together.
>There are the two types of nitrogenous bases.
(i) Pyrimidines – Cytosine, Uracil, Thymine
(ii) Purines – Adenine and Guanine.

Chargaff’s rule:
Chargaff’s rule was discovered by the Austrian born chemist Erwin Chargaff in the late 1940s.
Chargaff’s rule states that the DNA from any cell of any organism should have the ratio of pyrimidine and purines equal to 1:1.
This rule also states that the amount of Guanine must be equal to the amount of Cytosine and the amount of Adenine must be equal to the amount of Thymine.
 That means - %G = %C and %A = %T
 Given in question-
T = 40%
C = 10%
G = ?
As stated in Chrgaff’s rule %G = %C
As C = 10% (given in question), so G must be equal to 10%. (according to the chargaff’s rule).
Therefore, it has been clear from the above discussion that in a pollen grain, if T=40%, C=10%, then G=10%.

Hence, option B is the correct answer for this question.

Note:Many allergic disorders can be caused by the pollen grains. Nasal energy to pollen is called pollinosis. Pollen grains can be used as dietary supplements. Pollen grains constitute carbohydrates and protein content which ranges from 7% to 35% depending upon the plant species.