Class 10 Science Practice Question Answers - Genetics

Questions

1. Give definition of heredity.

2. What do you mean by variations ?

3. Where genes present in organisms ?

4. Differentiate between autosomes & sex chromosomes.

5. Explain the terms genotype & phenotype.

6. Differentiate between Monohybrid cross & Dihybrid cross.

7. Give definition of hybridization.

8. What do you mean by pure - breeding ?

9. Differentiate character and trait.

10. Give definition of Allele.

Very short answer type question

1. What is a gene ?

2. Write the scientific term used for 'science of heredity and variation'.

3. Define inheritance.

4. What term did Mende use for what we now cal the genes ?

5. How does the creation of variations in a species promote surviva ?

6. Name the plant on which Mende performed his experiments.

7. Define Variation.

8. What are the carriers of factors or genes ?

9. Name two human traits which show variation.

10. Write down five inherited 'characters' or traits.

11. Which of the following combinations of sex chromosomes produces a male child, XX or XY ?

12. Which type of sex chromosomes are carried by male gametes - sperms in human male ? What is their percentage?

13. What experiment would we do to confirm that the F₂ generation did in fact have a 1 : 2 : 1 ratio of TT, Tt and tt trait combinations ?

Short answer type questions

1. Why did Mende choose pea plants for his experiment ?

2. What is Mendel's genetics ?

3. 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 ?

4. A Mendelian experiment consists in breeding tal pea plants bearing violet flowers with short pea plants bearing white flowers. The progeny al bore violet flowers, but almost half of them are short. This suggests that the genetic makeup of the tal parent can be depicted as :-

(i) TTWW (ii) TTww (iii) TtWW (iv) TtWw

5. Explain the mechanism of sex determination in human beings.

6. Define genetics. What is the contribution of Mende in this branch of Biology ?

7. Why are asexually reproducing organisms capable of showing the hereditary features more ?

8. With suitable example highlight how temperature has an effect on sex determination in the anima world.

9. Explain with an example how trait is inherited in human beings.

10. Why are traits acquired during the life-time of an individua not inderited ?

11. How does the creation of variations in a species ensure surviva ?

12. A man with blood group A marries a woman with blood group O and their daughter has blood gruop O. Is this information enough to tel you which of the traits - blood group A or O — is dominant ? Why or why not ?

13. Why are the smal numbers of surviving tigers a cause of worry from the point of view of genetics ?

14. Draw a schematic diagram to explain the independent inheritance of two separate traits, shape and colour of seeds.

15. How do Mendel's experiments show that traits are inherited independently ?
 

Long answer type questions

1. Explain diagramatically a Mendel's dihybrid cross.

2. Briefly explain contributions of Mende in Genetics.