A man with blood group B marries a woman with blood group O, and their daughter has blood group O. Is this information sufficient to tell you which of the traits, i.e., blood group B or O is dominant? Why or why not?

Sexual reproduction brings marked variation in the offspring’s while asexual reproduction does not. Why?

What is hereditary?

What do you understand by monohybrid and dihybrid cross performed by Mendel?

What is the cause of variation?

A change in DNA that is useful for one property to start with can become useful later for a different function. Explain.

Name the scientific terms used to represent the following:

i. The branch of biology dealing with the study of heredity and variation

ii. The transmission of traits from parents to offspring.

In human beings, the statistical probability of getting either a male or a female child is 50:50. Justify this statement with the help of a diagram.

What are homologous structures? Give an example. Is it necessary that homologous structures always have a common ancestor?

How is the sex of an offspring determined in the zygote in human beings? Explain with suitable diagram showing the cross between male and female gametes.

What is natural selection? List the main concepts of Darwin’s theory of natural selection.

“The sex of a newborn individual in some species is largely determined genetically, while in others it is otherwise” Give three different examples to justify this statement.

Give reasons why acquired characters are not inherited.

Name the descendants of wild cabbage. How were they developed?

How do variations arise in organisms? “Variation is useful for the survival of species.” Justify this statement with the help of an example.

What are fossils? How do they act as evidence for organic evolution?

Bacteria have a simpler body plan when compared with human beings. Does it mean that human beings are more evolved than bacteria? Provide a suitable explanation.

Why are flippers of whales and wings of birds considered as homologous organs?

Explain the struggle for existence.

Study the following cross and showing self-pollination in F_1, fill in the blank and answer the question that follows:

In the above cross what are the combinations of character in the F₂ progeny? What are their ratios?