Q1. How the body temperature is maintained ?
(a) Due to temperature regulating mechanism located in the base of the brain
(b) Due to excessive intake of water
(c) Due to regular intake of foods
(d) Due to the constant flow of blood in the capillaries
(UPSC Prelims 1981)
Answer: (a) Due to temperature regulating mechanism located in the base of the brain
Explanation: The hypothalamus, located at the base of the brain, acts as the body’s thermostat. It regulates heat production and loss, maintaining a stable internal temperature through mechanisms like sweating, shivering, and blood flow adjustments.
Q2. The messages received by and transmitted from the brain to the various parts of the body take the form of
(a) Nervous impulses
(b) Chemical impulses
(c) Mechanical impulses
(d) Automatic impulses
(UPSC Prelims 1983)
Answer: (a) Nervous impulses
Explanation: The brain communicates with the body through nervous impulses, which are electrical signals transmitted via neurons. These impulses control movement, sensation, and reflexes, forming the basis of the nervous system’s function.
Q3. Which of the following is a perception without stimuli ?
(a) Hallucination
(b) Illusion
(c) Claustrophobia
(d) None of these
(UPSC Prelims 1984)
Answer: (a) Hallucination
Explanation: A hallucination is a false sensory perception occurring without any external stimulus. It can affect any of the senses and is often associated with mental health conditions or substance use.