Class 10 Biology Chapter 4 - Heredity Important Questions 

Most Important Questions:-

Question 1.

“Only variations that confer an advantage to an individual organism will survive in a population.” Justify this statement. 

Answer:

Variations are the structural, functional or behavioural changes from the normal characters developed in the living organisms. Inheritable variations participate in evolution. According to Darwin, natural selection sorts out individuals with favourable variations. Such organism will survive, reproduce more and thus, will leave more progenies. Hence, useful variations get established in nature.

Question 2.

Assertion (A) : The sex of a child in human beings will be determined by the type of chromosome he/she inherits from the father.

Reason (R) : A child who inherits ‘X’ chromosome from his father would be a girl (XX), while a child who inherits a ‘Y’ chromosome from the father would be a boy (XY).

(a) Both (A) and (R) are true and (R) is the correct explanation of the assertion (A).

(b) Both (A) and (R) are true, but (R) is not the correct explanation of the assertion (A).

(c) (A) is true, but (R) is, false.

(d) (A) is false, but (R) is true. 

Answer:

(a) Both (A) and (R) are true and (R) is the correct Explaination of (A)

Question 3

Why is the progeny always tall when a tall pea plant is crossed with a short pea plant? 

Answer:

When a tall pea plant is crossed with a short pea plant, the resultant progeny is always tall because tall is dominant trait and short is recessive trait. Therefore, dominant trait expresses itself in the progeny.

Question 4.

What is heredity? 

Answer:

The inheritance of characters (or trails) from the parents to their offsprings is called heredity.

Question 5

 Do genetic combination of mothers play a significant role in determining the sex of new born?

Answer:

No, mothers have no role in determining the sex of the new born. Mothers have a pair of X chromosome. And all children will inherit an ‘X’ chromosome from their mother regardless of whether they are boys or girls.

Question 6

Give reasons why acquired characters are not inherited.

Answer.

 Acquired characters are not inherited because they do not produce change in the DNA of germ cells, only those characters which have a gene for them can be inherited.

Question 7.

 Give reasons for the appearance of new combinations of characters in the F2 progeny.

Answer:

An organism can inherit each character independently. So, in the F2 progeny new combination of character appears. Tall/ Short and Round/Wrinkled seed trait are independently inherited.