Rachna is an expert gymnast on the balance beam. She has been vigorously practising for the Olympic
Games. Lately, she has been experiencing dizziness and losing her balance during the practise sessions.
(a) Which part of the membranous labyrinth is responsible for maintaining the body balance on the
beam?
(b) Which type of balance is maintained by the structure mentioned in (a)?

15] Select the correct answers to the questions from the given options. (Do not copy the questions, write the correct answer only).
The structure that lies at the junction of the choroid and the iris and is itself a part of the choroid is called:

15] Select the correct answers to the questions from the given options. (Do not copy the questions, write the correct answer only).
The optimum temperature for photosynthesis is:

Given below is a picture of a tree. Mention the scientific phenomena occurring in the parts labelled (a),
(b) and (c).
(c)
(b)
(a)

15] Select the correct answers to the questions from the given options. (Do not copy the questions, write the correct answer only).
The number of live births per thousand people per year is called:

What are biomedical wastes? Give an example.

State any two harmful effects of acid rain.