Control and Coordination — Questions & Answers

Sample questions from Control and Coordination

1. Q1. The hormone released during emergency situations is:

   • A.adrenaline✓
   • B.insulin
   • C.thyroxine
   • D.auxin
   Solution

   Adrenaline prepares the body for emergency responses.

2. Q2. When an electrical impulse reaches the nerve ending of a neuron, what happens at the synapse?

   • A.The impulse jumps directly as an electric spark
   • B.A chemical is released which starts a fresh impulse in the next neuron✓
   • C.The impulse is converted into heat energy
   • D.The impulse is stored until the muscle responds
   Solution

   At the synapse the electrical signal causes release of a chemical that crosses the gap and sets off a new electrical impulse in the next neuron.

3. Q3. The leaves of the touch-me-not plant fold when touched. Unlike the bending of a shoot towards light, this movement:

   • A.is not a growth movement, and is caused by cells changing their water content✓
   • B.is a growth movement caused by auxin
   • C.happens in the direction of the stimulus
   • D.takes several hours to become visible
   Solution

   Cells at the base of the leaf lose water and go limp, so the leaf folds within seconds and recovers later — nothing has grown. Phototropism, by contrast, is slow, permanent and directional because it is caused by unequal growth.

4. Q4. Why does a neuron have a long axon?

   • A.To carry impulses over a distance✓
   • B.To digest proteins
   • C.To produce red blood cells
   • D.To store starch
   Solution

   A long axon can transmit impulses between distant parts of the body.

5. Q5. A person touches a hot pan, withdraws the hand, then feels pain. This sequence shows:

   • A.rapid spinal reflex followed by conscious brain processing✓
   • B.only hormone action
   • C.digestion followed by excretion
   • D.plant tropism
   Solution

   The withdrawal can be coordinated by the spinal cord before pain is consciously interpreted.

Other Class 10 Biology chapters