CBSE Questions for Class 11 Medical Biology Plant Growth And Development Quiz 11 - MCQExams.com

$$\textbf{Correct option: }$$ C

$$\textbf{ Solution: }$$  

$$\textbf{ Option (a): }$$

$$\bullet$$ Gibberellin are involved in seed germination in certain plants.

$$\bullet$$ Gibberellins breaks the  seed's dormancy and allows the occurrence of seed germination. 

$$\bullet$$ It also breaks the bud dormancy which is defined as the inactive state achieved by the meristem of the plants. 

$$\textbf{ Option (b): }$$

$$\bullet$$ Auxin is produced by the cells present on the tip of the stems and roots. This tip of the stem is composed of cells of apical meristem which produces auxin hormone. 

$$\bullet$$ The bending of the stem of plants towards light is promoted by auxin which is a plant growth hormone. 

$$\textbf{ Option (c): }$$

$$\bullet$$ Cytokinins are the plant hormone that promotes the growth of the plant.

$$\bullet$$ Cytokinins promote the ageing of leaves (delay senescence) and also help in breaking the dormancy of seeds and buds.

$$\bullet$$ This hormone is also synthesized in the root cap  which can promote cytokinesis,induce the cell division, vascular differentiation and root apical dominance 

$$\textbf{ Option (d): }$$

$$\bullet$$ Ethylene is located in the nodes of the stem, ripening fruits, and dying leaves. 

$$\bullet$$ This hormone functions in promoting the ripening of fruit, inhibiting the growth and development of roots, leaves, and flowers. 

$$\bullet$$ This hormone is also the only hormone that is present in the gaseous form. 

Hence, the correct option is (c).

$$\textbf{Correct option: }$$ A

$$\textbf{ Solution: }$$  

$$\textbf{ Option (a): }$$

$$\bullet$$ Ethylene is located in the nodes of the stem, ripening fruits, and dying leaves. 

$$\bullet$$ This hormone functions in promoting the ripening of fruit, inhibiting the growth and development of roots, leaves, and flowers.

$$\bullet$$ Hence, this hormone can control abscission of leaf, flower and fruit. 

$$\textbf{ Option (b): }$$

$$\bullet$$ This hormone is also the only hormone that is present in the gaseous form. 

$$\bullet$$ Auxin is produced by the cells present on the tip of the stems and roots. This tip of the stem is composed of cells of apical meristem which produces auxin hormone. 

$$\bullet$$ The bending of the stem of plants towards light is promoted by auxin which is a plant growth hormone. 

$$\textbf{ Option (c): }$$

$$\bullet$$ Gibberellin are involved in seed germination in certain plants.

$$\bullet$$ Gibberellins breaks the  seed's dormancy and allows the occurrence of seed germination. 

$$\bullet$$ It also breaks the bud dormancy which is defined as the inactive state achieved by the meristem of the plants.

$$\textbf{ Option (d): }$$

$$\bullet$$ Cytokinins are the plant hormone that promotes the growth of the plant.

$$\bullet$$ Cytokinins promote the ageing of leaves (delay senescence) and also help in breaking the dormancy of seeds and buds.

Hence, the correct option is (a).