Plant Kingdom — BIOLOGY STD 11 Science — Question

What is the role of second messenger in hormone action?

Deepak, (student of XI class), attended a seminar on plant growth and development. As Deepak also belongs to the farmer's family, he was enthusiastic to know upcoming experiments in the field of botany. Guest of the seminar told the students that development in plants is under the control of various intrinsic and extrinsic factors. The intrinsic factors include intracellular or genetic factors as well as intercellular factors like plant growth regulators. Deepak asked the guest about the role of growth regulators used to improve the yield of plants. The guest speaker cleared all doubts of Arun and then Arun returned home happily from the seminar he visited.

1. What are the two groups of PGRs, based on their functions?
2. Give an example of each of the two types.
3. It is said that PGRs may function synergistically of antagonistically. What is meant by these two terms? Give an example for each.
4. What value can be learnt by the nature of Deepak (as a XI class student).

Find out how Melvin Calvin worked out the complete biosynthetic pathway for synthesis of sugar.

Write semi-technical description of the family Liliaceae. Describe its economic importance.

Write the function of the following in case of frog:

1. Tongue.
2. Pigment cells.
3. Vocal sacs.
4. Mucous glands.
5. Tympanic membrane.

What is oxidative phosphorylation?

Formation of enzyme-substrate complex (ES) is the first step in catalysed reactions. Describe the other steps till the formation of product.

How many types of plastids are there on the basis of colour? Draw a diagram of chlorophyll and describe it.

Complete the following table by filling the blanks marked (A-F) below.

Essential element	Macro or Micro/ Region of requirement	Function	Dificiency
Boron	Micro/ apical leaves and seeds	Elongation of pollen tube	____ (A) ____
____ (B) ____	Micro/ whole plant	Involved in OXi-red reactions	Development of necrotic spots
Phosphorus	____ (C) ____	____ (D) ____	Structed plants
Magnesium	Macro/ growing areas of root and stems	____ (E) ____	____ (F) ____

Mention any three similarities and two differences between facilitated diffusion and active transport of substances in plants. Also draw a neat labelled diagram depicting facilitated diffusion of proteins.