Sheila saw a snake and instantly jumped back. She then slowly moved away from the snake. What is the difference between the two actions of instantly jumping and walking away?
Important Questions on Control and Coordination
'Plant growth regulators do not always promote growth.'
Cite one example in support of the above statement and mention the action of the same.
The two glands A and B which occur in pairs are present in the endocrine system of humans. The pair of glands A is found only in females whereas the pair of glands B occurs only in males. The glands A make and secrete two hormones C and D whereas glands B make and secrete only one hormone E. In addition to hormones, glands A make gametes F whereas glands B make gametes G.
What are glands A and B?
(i) Growing of pollen tube in response to a sugary substance.
(ii) Folding up of leaves of the sensitive plant in response to touch.
(iii) Winding of tendril around a support in response to touch.
(iv) Opening up of the leaves of a daisy flower in response to light.
Observe the figure and answer the following question.
What changes do you observe in the growth of root and stem in a plant, if it is kept stationary as shown in the figure for a few days why?
The changes that are likely to happen in the plant in the following picture:
(A) A hormone abscisic acid is synthesised at the shoot tip.
(B) When light is coming from one side of the plant, auxin diffuses towards the shady side of the plant.
(C) Abscisic acid helps the cells to grow longer.
(D) Cells grow longer on the side of the shoot which is away from light.
Select the correct option.
Match the columns.
| 1. cerebrum | a. controls reflex action |
| 2. spinal cord | b. takes messages from the brain |
| 3. brain stem | c. controls thinking |
| 4. motor nerve | d. controls balance |
| 5. cerebellum | e. controls involuntary muscle |
