66. Which region of the alimentary canal absorbs the digested food?
(a) Stomach
(b) Small intestine
(c) Large intestine
(d) Liver
Answer:
(b) Small intestine
Explanation:
The small intestine has millions of tiny finger-like projections called villi, which massively increase surface area for the absorption of digested nutrients into the bloodstream.
67. When a few drops of iodine solution are added to rice water, the solution turns blue-black in colour. This indicates that rice water contains:
(a) fats
(b) complex proteins
(c) starch
(d) simple proteins
Answer:
(c) starch
Explanation:
The iodine test is a classic chemical indicator test for the presence of starch. Iodine solution reacts with starch to produce a deep blue-black color.
68. Glycolysis process occurs in which part of the cell?
(a) Cytoplasm
(b) Nucleus
(c) Mitochondria
(d) Chloroplast
Answer:
(a) Cytoplasm
Explanation:
Glycolysis, the first step of cellular respiration where glucose is broken down into pyruvate, takes place in the cytoplasm of the cell.
69. Which parts of the brain control blood pressure?
(a) Spinal cord, skull, hypothalamus
(b) Cord, skull, cerebrum
(c) Pons, medulla, cerebellum
(d) Pons, medulla, pituitary
Answer:
(c) Pons, medulla, cerebellum
Explanation:
Involuntary actions like blood pressure, salivation, and vomiting are controlled largely by the medulla and pons in the hindbrain. (Note: Option C is the standard textbook answer block containing these hindbrain structures).
70. Which part of the brain controls posture and balance in the body?
(a) Cerebrum
(b) Cerebellum
(c) Medulla
(d) Pons
Answer:
(b) Cerebellum
Explanation:
The cerebellum, located at the back of the brain, coordinates voluntary movements and is responsible for maintaining posture and balance.
