Following questions consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below:
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Q.1. Assertion(A) : Insulin regulates blood sugar level.
Reason (R) : Insufficient secretion of insulin will cause diabetes.
Q.2. Assertion(A) : Animals can react to stimuli in different ways.
Reason (R) : All animals have a nervous system and an endocrine system involving hormones.
Q.3. Assertion(A): The effect of auxin hormone on the growth of root is exactly opposite to that on a stem.
Reason (R) : Auxin hormone increases the rate of growth in root and decreases the rate of growth in stem.
Q.4. Assertion(A): A receptor is a specialized group of cells in a sense organ that perceive a particular type of stimulus.
Reason (R) : Different sense organs have different receptors for detecting stimuli.
Q.5. Assertion(A): Cyton region of nerve fibre collects information for the brain.
Reason (R): Nerve fibres can either have or lack myelin sheath.
Q.6. Assertion(A): A nerve impulse is an electrochemical event.
Reason (R) : In a nerve impulse there are changes in the resting potential which spreads down the nerve fibre.
Q.7. Assertion(A) : The brain is also known as the central nervous system.
Reason (R) : Central nervous system controls and regulates the voluntary actions.
Q.8. Assertion(A) : The spinal nerves are 31 in number.
Reason (R) : Spinal nerves only have sensory neurons in them