Control and coordination Worksheet-34

Control and coordination Worksheet-34

True / False:

1. The function of control and coordination in plants is performed by the chemical substances called plant hormones.

2. The plant hormones are also called phytohormones.

3. The movement of a plant part in response to light is called geototropism.

4. The stem (or shoot) of a plant shows negative phototropism.

5. The movement of a plant parting response to a chemical stimulus is called phototropism.

6. The growth of pollen tube towards the ovule during the process of fertilization in a flower is an example of chemotropism.

7. Tendrils of plants are positively hydrotropic.

8. The folding up of the leaves of a sensitive plant (Mimosa pudica) on touching is an example of nastic movement.

9. The opening up of the petals of dandelion flowers in morning in bright light and closing in the evening when the light fades is an example of phototropic movement.

10. All tropisms are growth movement but all nasties are not growth movements.

11. The non-directional movement of a plant part in response to the touch of an object is called thigmonsty.

12. The sensitive plant has pad-like swelling called ‘pulvini’ at the base of each leaf.

13. Cytokinins are the plant hormones which promote cell enlargement and cell differentiation in plants.

14. Gibbererllins help in breaking the dormancy in seeds and buds.

15. Cytokinins are the plant hormones which promote cell division in plants.

16. Abscisic acid promote the opening of stomata.

17. Cytokinins delay the ageing in leaves.

18. Abscisic acid is a plant hormone which functions mainly as a growth inhibitor.

19. Cytokinins promotes the dormancy in seeds and buds.

20. Abscisic acid work antagonistically to cytokinins.

Answer:

1. True

2. True

3. False

Explanation: The movement of a plant part in response to light is called phototropism

4. False

Explanation: The stem (or shoot) of a plant shows positive phototropism.

5. False

Explanation: The movement of a plant parting response to a chemical stimulus is called chemotropism.

6. True

7. False

Explanation: tendrils of plants are positively thigmotropic.

8. True

9. False

Explanation: The opening up of the petals of dandelion flowers in morning in bright light and closing in the evening when the light fades is an example of nastic movement.

10. True

11. True

12. True

13. False

Explanation: Auxins are the plant hormones which promote cell enlargement and cell differentiation in plants.

14. True

15. True

16. False

Explanation: Cytokinins promote the opening of stomata

17. True

18. True

19. True

20. True