NCERT Solutions for Heredity Class 10 Chapter 8 Science has all the solutions to the questions provided in the NCERT Book of the latest edition.
Students are advised to practice all the questions to get good marks in the board examination.
| Textbook | NCERT |
| Class | 10 |
| Subject | Science |
| Chapter | 8 |
| Chapter Name | Heredity |
| Category | NCERT Solution |
Class 10 Science Chapter 8 Heredity NCERT Solution
Heredity Intext Questions Page 129
If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?
Answer
Trait B is more likely to arise earlier than trait A, as it is already present in 60% of the population and will spread at a higher rate.
How does the creation of variations in a species promote survival?
Answer
Variation leads to evolution which will ultimately help the species to survive environmental changes.
Heredity Intext Questions Page 133
How do Mendel’s experiments show that traits may be dominant or recessive?
Answer
Mendel showed that a trait can be dominant or recessive, by monohybrid cross.
As he used the tall plant of allele (T) and short plant of allele (t), when crossed they produced traits having TT, Tt and tt in the second generation. TT means tall and tt means small, but Tt meant to be tall not any intermediate height. So here T is dominant over t.
How do Mendel’s experiments show that traits are inherited independently?
Answer
It was shown by a dihybrid cross. Here he used two traits, round seed (R)and wrinkled seed(r), and yellow(Y) and green(y) colored seed.
The round is dominant over wrinkled and yellow dominant over green. The F2 generation had a phenotype of 9:3:3:1. Where 9 were Round and Yellow seeds (RRYY), 3 were Round and green (RRyy), 3 were wrinkled and yellow (rrYY) and 1 was wrinkled and green (rryy). Thus this shows that the gametes segregate independently and are inherited accordingly
A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?
Answer
No, this information is not enough. In the ABO blood grouping system the A blood group is always dominant over the O blood group.
In this case the father must have the genotype of AO which resulted in the OO genotype of their daughter.
How is the sex of the child determined in human beings?
Answer
The males have genotype of XY and female have genotype of XX, thus gametes produced by males are X and Y while females produce only X.
When X sperm meets X ovum the resulting zygote will have XX which is a female. If the Y sperm meets with the X ovum the resulting zygote will be of XY which is a male.
Heredity Exercise Questions
A Mendelian experiment consisted of breeding tall pea plants bearing violet flowers with short pea plants bearing white flowers. The progeny all bore violet flowers, but almost half of them were short. This suggests that the genetic make-up of the tall parent can be depicted as
Answer
C) TtWW
A study found that children with light-coloured eyes are likely to have parents with light-coloured eyes. On this basis, can we say anything about whether the light eye colour trait is dominant or recessive? Why or why not?
Answer
We should have knowledge of atheist three generations to identify whether a trait is dominant or recessive.
Here in this case we cannot say if the light colour of the eye is dominant or recessive
Outline a project which aims to find the dominant coat colour in dogs.
Answer
Dogs have many coat colors, for example let us take B series here black will be denoted by B and brown by b.
When we cross them Bb will be formed, this is black color with heterozygous genotype. In F2 generation it will produce BB, Bb, and bb, in 1:2:1 ratio
F2 Generation:
| B | b | |
| B | BB | Bb |
| b | Bb | bb |
How is the equal genetic contribution of male and female parents ensured in the progeny?
Answer
This is ensured by inheriting an equal number of chromosomes from both the parents.
Example: in humans, offspring have 23 pairs of chromosomes (total 46) out of which 23 are inherited from father and 23 from mother.
Hope NCERT Solutions for Class 10 Science Chapter 8 Heredity, helps you in solving problems. If you have any doubts, drop a comment below and we will get back to you.