Neural Control And Coordination

Answer (a) Fovea centralis

Man has 31 pairs of spinal nerves. These are [a] Cervical ? 8 pairs in neck [b] Thoracic ? 12 pairs in thorax [c] Lumbar? 5 pairs in upper part of abdomen [d] Sacral ? 5 pairs in lower part of abdomen [e] Coccygeal ? tail nerve. Frog has 10 pairs of spinal nerves, while rabbit has 37 pairs of spinal nerves.

Answer (a) Rhodopsin

Human eyes have remarkable power of accommodation by changing the convexity of the lens. Due to action of the muscles of ciliary body and suspensory ligament the focal length of the lens can be changed. Then the objects can be focused in different intensity of light from varying distances. For accommodation of distant objects, ciliary muscles are relaxed and suspensory ligaments are tightly stretched.

Answer (c) Bipolar neuron

Answer (d) It is a region of retina with only cone cells

Step 1: Understanding the Question.
The question asks about the correct relationships in the central nervous system and whether any of the given associations are incorrect.

Step 2: Analyzing the Options.
(A) Kidney → Neuron: Incorrect — The kidney is part of the excretory system, not directly related to neurons in the nervous system.
(B) Lemur → Monkey: Correct — Lemurs are often classified under primates, similar to monkeys.
(C) Bravery → Confidence: Correct — Bravery is often associated with confidence.
(D) None of the above: This is incorrect, as (A) is wrong.

Step 3: Conclusion.
The correct answer is (A) Kidney → Neuron, as this is an incorrect association.

Step 1: Understanding the Concept:
The human brain is divided into the forebrain, midbrain, and hindbrain. Different regions manage distinct functions ranging from basic survival to complex thought.
Step 2: Detailed Explanation:
The Cerebrum is the largest part of the brain and is responsible for high-level functions, including voluntary actions (like walking or talking), memory, and decision-making. The cerebellum coordinates balance, while the medulla controls involuntary actions like heartbeat.
Step 3: Final Answer:
The correct option is (c).