8. Heredity Science class 10 in English Medium ncert book solutions Additional Questions With Solutions

Extra Important Questions with Answers – Chapter 8: Heredity

Q1: What is heredity?

Ans: Heredity is the process by which characteristics are passed from parents to their offspring through genes.

Q2: What are inherited traits?

Ans: Inherited traits are characteristics that are passed from parents to offspring through genes.

Q3: What are acquired traits?

Ans: Acquired traits are characteristics developed during an individual's lifetime due to environmental influences. They are not inherited.

Q4: What is variation?

Ans: Variation refers to the differences in characteristics among individuals of the same species.

Q5: Why is variation important?

Ans: Variation helps organisms adapt to changing environmental conditions and increases their chances of survival.

Q6: What is a gene?

Ans: A gene is the basic unit of heredity that controls the inheritance of a specific trait.

Q7: Where are genes located?

Ans: Genes are located on chromosomes inside the nucleus of a cell.

Q8: What are chromosomes?

Ans: Chromosomes are thread-like structures made of DNA and proteins that carry genetic information.

Q9: What is DNA?

Ans: DNA (Deoxyribonucleic Acid) is the genetic material that carries hereditary information from one generation to the next.

Q10: What is a trait?

Ans: A trait is a specific characteristic or feature of an organism, such as eye color or plant height.

Q11: What is Mendel's law of dominance?

Ans: Mendel's law of dominance states that when two contrasting traits are present together, only the dominant trait is expressed in the offspring.

Q12: What are dominant and recessive traits?

Ans: A dominant trait is expressed even in the presence of one dominant allele, while a recessive trait is expressed only when both alleles are recessive.

Q13: What is an allele?

Ans: An allele is an alternative form of the same gene that controls a particular trait.

Q14: What is genotype?

Ans: Genotype is the genetic makeup or combination of alleles present in an organism.

Q15: What is phenotype?

Ans: Phenotype is the observable physical appearance or expressed characteristics of an organism.

Q16: Differentiate between genotype and phenotype.

Ans: Genotype refers to the genetic constitution of an organism, whereas phenotype refers to its visible characteristics.

Q17: What is a monohybrid cross?

Ans: A monohybrid cross is a cross involving only one pair of contrasting traits.

Q18: What phenotypic ratio is obtained in the F₂ generation of a monohybrid cross?

Ans: The phenotypic ratio is 3 : 1.

Q19: What genotypic ratio is obtained in the F₂ generation of a monohybrid cross?

Ans: The genotypic ratio is 1 : 2 : 1.

Q20: What is a dihybrid cross?

Ans: A dihybrid cross is a cross involving two pairs of contrasting traits.

Q21: State Mendel's law of segregation.

Ans: The two alleles of a gene separate during gamete formation, and each gamete receives only one allele.

Q22: State Mendel's law of independent assortment.

Ans: Different pairs of alleles assort independently during gamete formation.

Q23: What is a sex chromosome?

Ans: Sex chromosomes determine the sex of an individual. In humans, they are X and Y chromosomes.

Q24: How is the sex of a child determined in humans?

Ans: The father determines the sex of the child. An X-bearing sperm produces a girl (XX), while a Y-bearing sperm produces a boy (XY).

Q25: Why can't acquired traits be inherited?

Ans: Acquired traits do not affect the DNA of reproductive cells, so they cannot be passed on to the next generation.

Q26: Why are variations beneficial to a species?

Ans: Variations help species survive environmental changes and increase the chances of evolution.

Q27: What is evolution?

Ans: Evolution is the gradual change in inherited characteristics of organisms over many generations.

Q28: What is the relationship between heredity and evolution?

Ans: Heredity passes variations to offspring, and the accumulation of useful variations over generations leads to evolution.

Q29: Why did Mendel choose pea plants for his experiments?

Ans: Mendel chose pea plants because they have distinct contrasting traits, a short life cycle, and can self-pollinate as well as cross-pollinate easily.

Q30: Name any four contrasting characters studied by Mendel in pea plants.

Ans: Tall/Dwarf plants, Round/Wrinkled seeds, Yellow/Green seeds, and Violet/White flowers.

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