CBSE – 10th Standard Science

Class 10 Question Bank Chapter 9 – Heredity and Evolution

Qus1. What is the main source making proteins in the cell?

Ans. Cellular DNA is the information source for making proteins in the cell.

Qus 2. Explain the term ‘Gene’?

Ans. A section of DNA that provides information for one protein is called the gene for that protein.

Qus 3. What does Darwin’s theory of evolution tells us?

Ans. Darwin’s theory of evolution tells us how life evolved from simple to more complex forms.

Qus 4. What is dominant trait?

Ans. Sexually reproducing individuals have two copies of genes for the same trait. If the copies are not identical, the trait that gets expressed is called the dominant trait.

Qus 5. How is sex determined in human beings?

Ans. In human beings, the sex of the child is determined on whether the paternal chromosome is X (for girls) or Y (for boys).

Qus 6. What is Evolution?

Ans. Evolution is simply the generation of diversity and the shaping of the diversity by environmental selection.

Qus 7. What are the tools for tracing evolutionary relationships?

Ans. The  tools for tracing evolutionary relationships are excavating, time-dating and studying fossils.

Qus 8. What is the basic unit of life in all organisms?

Ans. The cell is the basic unit of life in all organisms.

Qus 9. What are fossils?

Ans. When organisms die, their bodies will decompose and be lost but when the body or some parts may be in an environment that does not let it decompose completely and such decompose traces of an organisms are called fossils.

Qus 10. Name the earliest members of the human species?

Ans. The earliest members of the human species are  Homo sapiens.

Que.11 . How does the creation of variations in a species promote    survival?

Depending on the nature of variations, different individuals would have different kinds of advantages. Bacteria that can withstand heat will survive better in a heat wave, as we have discussed earlier. Selection of variants by environmental factors forms the basis for evolutionary processes

Que.12.Why are traits acquired during the life-time of an individual not inherited?

Ans. Any changes in somatic cells cannot be passed to DNA of germ cells.hence these traits are not inheritable.


Q.1.  Why are the small numbers of surviving tigers a cause of worry from the point of view of genetics?

Q.2. Can the wing of a butterfly and the wing of a bat be considered homologous organs? Why or why not?

Q.3. What are fossils? What do they tell us about the process of evolution? Explain the importance of fossils in deciding evolutionary relationships.

Q.4. What evidence do we have for the origin of life from inanimate matter?

Q.5.  Explain how sexual reproduction gives rise to more viable variations      than asexual reproduction. How does this affect the evolution of those organisms that reproduce sexually?