For two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below: a. Both A and R are true, and R is correct explanation of the assertion. b. Both A and R are true, but R is not the correct explanation of the assertion. c. A is true but R is false. d. A is false but R is true. Assertion: Internal fertilisation occurs in mammals and birds. Reason: External fertilisation occurs in reptiles, amphibians, and fishes.

What is internal energy reserve in plants? Do the animals have the same energy reserve? Justify your answer.

Updated 1/14/2026

(a) What are “hormones”? (b) List four characteristics of hormones (c) Name the hormone required for the following: Functioning of mammary glands Regulation of calcium and phosphate Lowering of blood glucose Development of moustache and beard in human malc.

Updated 1/13/2026

What is excretion? How do unicellular organisms remove their wastes?

Updated 1/13/2026

• What are chromosomes? Where are they seated? • What is a sex chromosome? • Explain the mechanism of sex determination in human beings.

Updated 1/13/2026

(a) In human body what is the role of • seminal vesicles and • prostate gland. (b) List two functions performed by testes in human beings.

Updated 1/13/2026