Plant Growth and Development BIOLOGY - Plant Growth and Development

Which one is a long day plant?

Cytokinins are byproducts of:

Bananas can be prevented from over-ripening by:

Phytocytomine is a:

Which one of the following is a natural growth inhibitor?

Define determinate growth.

Define meristem.

Define growth rate.

Define redifferentiation.

Define dedifferentiation.

Describe Geometric growth.

Describe Absolute and relative growth rates.

‘Both a short day plant and a long day plant can produce can flower simultaneously in a given place’. Explain.

Describe Arithmetic growth.

‘Both growth and differentiation in higher plants are open’. Comment.

Why is abscisic acid also known as stress hormone?

Would a defoliated plant respond to photoperiodic cycle? Why?

What are the structural characteristics of:

1. Meristematic cells near root tip?
2. The cells in the elongation zone of the root?

Arun visited his village in vacations to see his grandfather. He went to the field one day along with his grandfather where he observed the poor growth of the sugarcane. He discussed the issue and the reason behind this with his grandfather. Sugarcane is the main crop in their village. His grandfather asked him to suggest some methods in order to increase the yield of sugarcane, in a healthy way. Being a biology student Arun told his grandfather to use gibberellins (GA₃) spray on the sugarcane crop.

1. What are gibberellins?
2. What are other physiological responses influenced by gibberellins? Give arty two.
3. What message is conveyed by grandfather and Arun's character?

Give the chemical name of one example of each of the following and mention one function of each of them:

1. Natural auxins.
2. Synthetic auxins.
3. Gaseous plant hormones.

What do you understand by photoperiodism and vernalisation? Describe their significance.

What would be expected to happen if:

1. GA₃ is applied to rice seedlings
2. dividing cells stop differentiating
3. a rotten fruit gets mixed with unripe fruits
4. you forget to add cytokinin to the culture medium.

Why is not any one parameter good enough to demonstrate growth throughout the life of a flowering plant?

Which one of the plant growth regulators would you use if you are asked to:

1. induce rooting in a twig
2. quickly ripen a fruit
3. delay leaf senescence
4. induce growth in axillary buds
5. ‘bolt’ a rosette plant
6. induce immediate stomatal closure in leaves.

List five main groups of natural plant growth regulators. Write a note on discovery, physiological functions and agricultural/horticultural applications of any one of them.