A group of similar cells performing the same function is a tissue.

24. A group of similar cells performing the same function is a tissue.
The correct option is B.

$$\boxed{\text{B. Tissue}}$$

25. The male reproductive cell is sperm.
The correct option is B.

$$\boxed{\text{B. Sperm}}$$

26. The female reproductive cell is an ovum.
The correct option is B.

$$\boxed{\text{B. Ovum}}$$

27. Fertilization occurs in the fallopian tube.
The correct option is C.

$$\boxed{\text{C. Fallopian tube}}$$

28. Protein is the nutrient that builds the body.
The correct option is B.

$$\boxed{\text{B. Protein}}$$

29. Carbohydrate is the nutrient that gives energy.
The correct option is A.

$$\boxed{\text{A. Carbohydrate}}$$

30. Malaria is a disease caused by mosquitoes.
The correct option is B.

$$\boxed{\text{B. Malaria}}$$

31. The process of removal of waste is excretion.
The correct option is C.

$$\boxed{\text{C. Excretion}}$$

32. Malaria is a communicable disease.
The correct option is C.

$$\boxed{\text{C. Malaria}}$$

33. The breathing organ in humans is the lung.
The correct option is B.

$$\boxed{\text{B. Lung}}$$