Class 10 Science Heredity

Class 10 Science Heredity

 

Class 10 Science Heredity Fill in the blanks , Multiple Choice Question [mcq] and True false .

 

Fill in the Blanks

1. The process by which traits are passed from parents to offspring is called ________. Answer: Heredity

2. Variations are maximised in ________ reproduction. Answer: sexual

3. Mendel used ________ plants for his experiments on inheritance. Answer: pea

4. A trait that is expressed even when present in a single copy is called a ________ trait. Answer: dominant

5. The genetic makeup of an organism is called its ________. Answer: genotype

6. The physical expression of a trait is called its ________. Answer: phenotype

7. In humans, females have the sex chromosomes ________. Answer: XX

8. In humans, males have the sex chromosomes ________. Answer: XY

9. The F1 generation in Mendel’s experiments showed only the ________ trait.
Answer: dominant

10. The ratio of dominant to recessive traits in the F2 generation of a monohybrid cross is ________. Answer: 3:1

11. A section of DNA that codes for a protein is called a ________. Answer: gene

12. The process by which germ cells reduce their chromosome number by half is called ________. Answer: meiosis

13. The inheritance of one trait does not affect the inheritance of another trait, as per Mendel’s law of ________. Answer: independent assortment

14. In humans, the sex of the child is determined by the ________ chromosome contributed by the father. Answer: Y

15. Asexual reproduction leads to ________ variations compared to sexual reproduction. Answer: fewer

 

Class 10 Science Heredity Multiple Choice Questions

 

1. What is the main cause of variation in asexual reproduction?
(a) DNA copying errors
(b) Environmental factors
(c) Crossing over
(d) Mutation
Answer: (a) DNA copying errors

 

2. Which of the following is a recessive trait in pea plants?
(a) Tallness
(b) Round seeds
(c) Violet flowers
(d) Wrinkled seeds
Answer: (d) Wrinkled seeds

 

3. If a tall (Tt) pea plant is crossed with a short (tt) pea plant, what percentage of offspring will be tall?
(a) 25%
(b) 50%
(c) 75%
(d) 100%
Answer: (b) 50%

 

4. Which law of Mendel states that traits are inherited independently of each other?
(a) Law of Dominance
(b) Law of Segregation
(c) Law of Independent Assortment
(d) Law of Inheritance
Answer: (c) Law of Independent Assortment

 

5. In humans, a child will be male if he inherits which chromosome from his father?
(a) X
(b) Y
(c) XX
(d) XY
Answer: (b) Y

 

6. What is the genotypic ratio in the F2 generation of a monohybrid cross?
(a) 3:1
(b) 1:2:1
(c) 9:3:3:1
(d) 1:1
Answer: (b) 1:2:1

 

7. Which of the following is NOT a Mendelian trait in pea plants?
(a) Seed colour
(b) Flower position
(c) Blood group
(d) Pod shape
Answer: (c) Blood group

 

8. If a trait appears in 60% of a population, it is likely to have arisen ________ than a trait appearing in 10%.
(a) earlier
(b) later
(c) at the same time
(d) randomly
Answer: (a) earlier

 

9. Which process ensures genetic variation in sexually reproducing organisms?
(a) Mitosis
(b) Binary fission
(c) Meiosis
(d) Cloning
Answer: (c) Meiosis

 

10. What determines the sex of a child in humans?
(a) Mother’s chromosome
(b) Father’s chromosome
(c) Both parents equally
(d) Environmental factors
Answer: (b) Father’s chromosome

 

11. If a plant has the genotype Tt, what is its phenotype if “T” is dominant for tallness?
(a) Short
(b) Tall
(c) Medium
(d) Cannot be determined
Answer: (b) Tall

 

12. Which of the following is true about recessive traits?
(a) They always appear in the F1 generation.
(b) They are expressed only in homozygous condition.
(c) They are more common than dominant traits.
(d) They are never inherited.
Answer: (b) They are expressed only in homozygous condition.

 

13. What is the phenotypic ratio in a dihybrid cross?
(a) 3:1
(b) 1:2:1
(c) 9:3:3:1
(d) 1:1:1:1
Answer: (c) 9:3:3:1

 

14. Which of the following is an example of environmental sex determination?
(a) Humans
(b) Birds
(c) Reptiles
(d) Dogs
Answer: (c) Reptiles

 

15. What is the function of genes?
(a) To control protein synthesis
(b) To determine blood type only
(c) To regulate environmental factors
(d) To decide the sex of the child
Answer: (a) To control protein synthesis

 

True or False

1. True or False: Variations are more common in asexual reproduction than in sexual reproduction. Answer: False

2. True or False: Mendel’s experiments proved that traits are inherited independently. Answer: True

3. True or False: A child always inherits an X chromosome from the father.
Answer: False

4. True or False: In humans, the mother determines the sex of the child.
Answer: False

5. True or False: Dominant traits are always more common in a population.
Answer: False

6. True or False: The genotypic ratio of a monohybrid cross is 3:1. Answer: False

7. True or False: DNA is the genetic material that carries hereditary information.
Answer: True

8. True or False: Germ cells have half the number of chromosomes as somatic cells. Answer: True

9. True or False: All human cells contain 23 pairs of chromosomes. Answer: False (Germ cells have 23 single chromosomes.)

10. True or False: A recessive trait can skip generations. Answer: True

11. True or False: Mendel’s laws apply only to plants, not animals. Answer: False

12. True or False: The F1 generation in a monohybrid cross shows a 1:2:1 ratio.
Answer: False

13. True or False: Environmental factors can influence the expression of traits.
Answer: True

14. True or False: A dihybrid cross involves the study of two traits. Answer: True

15. True or False: In humans, blood group inheritance follows Mendelian principles.
Answer: True