Solved 2017 Question Paper ICSE Class 10 Biology — Question 12

The diagram given below is an external view of the human brain. Study the same and answer the questions that follow: [5]

(i) Name the parts labelled A, B and C in the diagram.

(ii) State the main functions of the parts labelled A and B.

(iii) What are the structural and functional units of the brain? How are the parts of these units arranged in A and C?

(iv) Mention the collective term for the membranes covering the brain.

(v) What is the function of Cerebrospinal fluid?

Answer

(i) The parts labelled A, B and C are:

• A → Cerebrum
• B → Cerebellum
• C → Spinal Cord

(ii) The functions are mentioned below:

• Cerebrum (Part A) — It is the seat of intelligence, consciousness and will power. It controls all voluntary activities.
• Cerebellum (Part B) — It coordinates muscular activities and maintains balance of the body.

(iii) Neurons / nerve cells are the structural and functional units of the brain.
In part A (Cerebrum), Outer grey matter has cytons and inner white matter has axons.
In part C (Spinal Cord), Outer white matter has axons and inner grey matter has cytons.

(iv) Meninges

(v) Cerebrospinal fluid(CSF) acts like a cushion to protect the brain / spinal cord from injuries and shocks.