BOT 121 PYQs

Q.1) Define Crop Physiology. Describe the Scope & Importance of Crop Physiology in agriculture

Importance of crop physiology :

The knowledge of plant physiology helps to study agricultural, horticultural, forestry and several other basic botany branch.
Plant Metabolic Process are responsible to increase in crop production.
The knowledge of crop physiology play an important role in production of new varieties and strains.
The basic knowledge of crop physiology can help in the increase of photosynthetic
conversion of solar energy in the production of food material.
The basic knowledge of atmospheric nitrogen fixation helps in increase utilization of atmospheric nitrogen by different plant species.
The detail knowledge of plant hormones facilitates growth and development of crop.
The study of plant physiology is important in agriculture to evaluate drought and stress.
It helps to evaluate nutritive values of cereals, pulses, oilseed, poultry and cattle field.
The Seed Physiology gives us an idea about the structure of seed and maturity of different crops

Scope of crop physiology :

To study, analyze, invent, investigate, interprete all the life process of plant.
To study the effect of various factor upon these life process.
To study the function of tissue & plant organ.
The knowledge can be used enhancing crop improvement & increase crop production

Q.2 ) Define Transpiration. What are the types of transpiration? Enlist the Factors that affect transpiration.

Transpiration : The loss of water in the form of vapours from the aerial part of the plant is known as transpiration.

Types of Transpiration

On the basis of loss of water, transpiration is categorized as follows :

1) Stomata Transpiration : 80-90 % water loss through stomata.

2) Cuticular Transpiration : 8-10 % water loss through the cuticle of the leaves and young stem.

3) Lenticular Transpiration : 0.1 % loss of water through the lenticells of fruits and woody stem.

Factors affecting Transpiration

• External Factors :
1) Atmospheric Humidity
2) Light
3) Temperature
4) Wind
5) Atmospheric Pressure
6) Available Soil Water
7) CO2 Content

• Internal Factors :
1) Internal Water Condition
2) Structural features
3) No. of Stomata /Structure of Stomata

Q.3 ) Define Plant Growth Regulator & Classify it. Write details about role of Auxins, Cytokinins & Gibberellins.

The substances or chemicals that are synthesized naturally in plant body in small amount which helps to promote growth as well as promotes cell division and shoot elongation.

CLASSIFICATION

A) Auxins

1. IAA - INDOLE ACETIC ACID

2. IBA - INDOLE BUTERIC ACID

3.NAA- NAPTHELIN ACETIC ACID

4. 2-4 D

B) Gibberelic acid

1 ) GA-3

C) Cytokinin

1. ZEATIN

2.KINETIN

D) Ethelyne

E) Absisic acid

ROLES OF PGRS ::

a) Auxin-

Apical meristem & young leaves are primary.

Site of auxin synthesis.

Physiological role-

1. cell elongation

2 Root initiation.

3. Apical dominance

4. Callus formation

5. Respiration.

b) Cytokinin-

Root ore principle site.

cytokinin production.

physiological role-

1. cell division

2. Regulate shoot root ratio

3. Delay senesence

4 cell enlargement

5. Apical dominance

6 chloroplast development.

Q.4 ) Enlist the Criteria for essentiality of Nutrient Elements. Write in short deficiency symptoms of following elements in plants: a) Nitrogen, B) Copper, C) Boron, D) Magnesium.

According to Arnon (1939) an essential element should posses the following criteria.

1) The essential element is indispensable for normal growth of the plants. When the plant is

deprived of this element normal growth is affected.

2) The essential element cannot be substituted by another element.

3) The essential element participates in a bio-chemical reactions of the plant.

4) The essential element produces deficiency symptoms when it is not given to the plant 5) The essential element is a part of the organic molecule.

DEFICIENCY SYMPTOMS

a) NITROGEN :

Yellowing of leaves due to loss of chlorophyll.

b) Copper :

Deficiency causes macrosis of the tip and margin of young leaves.

C) BORON :

Deficiency cause dead of shoot and root tip, leaves develop thick coppry texture, sometimes become curled and brittle.

D) MAGNECIUM :

Causes interveinal chlorosis first in the old leaves and then in young leaves.

Q.5) Define Respiration and Describe reaction of Kreb’s cycle.

Respiration is the process of biological oxidation where oxygen is utilized and CO2 evolved for the purpose of releasing energy.

Kreb's cycle: With the help of O2.pyruvic acid is completely oxidies into COa and FbO Maximum amount of energy is released by this process. It is also called as citric acid go trycarboxylic acid cycle and Kerb's cycle.

Acetyl co-enzyme is the intermediate product which links glycolysis and krebs cycle. During the oxidative phosphorylation 38 ATP molucle are formed out of which 8 ATP

Q.6 ) Define Growth. How growth is measured. Describe factors affecting Growth.

Growth- A permantant & irreversible chonge in size or volume of living structure.
with increase in dry weight.

Method :-

1. Direct method
2. Horizontal microscope
3. Auzanometer
4. Arc auxanometer
5. Pfeffer's auxanometer
6 Bose's cresograph
7- Space marker disc

Factors affecting on growth :

Light
Nutrients
Temperature
Humidity
Rainfall

Q.7) Define Photoperiodism. Describe the classification of Plants on the basis of Photoperiodic response.

Photoperiodism: Response of plants to elative length of the day and might required for flowering is known as photoperiodism

Classification :

1. Short day plant-

A plant which requires less than 12 hours of day length for the initiation ob blowering is called short day plant. It is also called as long night plant.
eg. rice, coffee.

2. Long day plant-

A plant which require more than 12 hours of day length for the initiation ob blowering is called long day plant. It is also called short night plant.
e.g. Pea, Radish.

3. Day neutral plant-

Day neutral plant produce blowers on their own accord with responding to the length of day and night.

Q.8) Define Photosynthesis. Describe in details about Dark reaction.. Enlist factors affecting

Photosynthesis.

Photosynthesis is defined as the process in which certain carbohydrates are synthesized from CO₂, and water by chlorophyll cells in the presence of light. Oxygen being a by product Dark reaction: In dark reaction the hydrogen (which is produced during light reaction) is transferred to CO₂, the reduction of CO₂ then proceeds rapidly in a stepwise manner under the action of several enzymes.

The reduction of CO₂, in stepwise manner with the help of several enzymes to the formation of sugars and starch and regeneration of (RuDP) ribulose 1.5, di-phosphate is called dark reaction.

First stable product of Calvin cycle or Ci plant is 2 molecules of 3 phospoglycerio (PGA). This is 3 C compound. It is operated in dicot plants. But in HSK pathway (C4 plant) the 1" stable product is oxaloacetic acid. It is 4C compound. In HSK pathway CO2 is fixed by phosphoenolpyruvic acid. But in Calvin cycle it is fixed by Ribulose -1-5 diphosphate (RuDP), HSK pathway is operative in monocot plants.

External Factors:

1) Light

2) Carbohydrates

3) Temperature

4) Water

5) Oxygen

Internal Factors:

1) Chlorophyll content

2) Protoplasmic factor

3) Leaf

4) Phytoharmone

Q.9) What is Fruit Ripening? What are the metamorphic changes that take place in ripening.

Fruit Ripening :- Ripening is a physiological process by which a mature fruit is made ready for eating by enzymatic break down of cell wall.

Metamorphic changes in Ripening (chemical biological changes):

metamorphic changes mean metabolic and morphological i.e. physical and chemical changes takes in ripening of fruit These changes are as under

a) Decrease in total CHO content and acid content.

b) Conversion of starch into sugar.

c) formation of polysaccharides.

d) Nitrogen status remains almost the same at the time of ripening, although a very small increase in proteins

e) Colour changes occurs with the increase in the pigments including chlorophyll

Q.10) What is Senescence? Give its Classification.

senescence: The deteriorative process which naturally terminates the functional life of an organ. Organism or other life unit are collectively called as Senescence.

Classification

Leopold (1961) has recognized 4 type of senescence patterns in plants which are as follows!

whole plant senescence / Overall:-
Shoot Senes
Decidous / Simultaineous
Progressive

Q.11) Write in detail about pathway of water across the root cells. Enlist the factors affecting rate of absorption.

Pathway of Water in Root The water is absorbed from the soil by the root hair et From the root hair cell, the water reaches the leaves by passing through a number of cells. Fr the root hair, the water reaches the endodermis. The endodermal cells lying opposite to root hairs are special modified to transport the absorbed water. These endodermal cells are called passage cells. The passage cells are permeable to water because they lack casparian thickening and t impermeable to water. into the pericycle cells. From the pericycle cells the

The water from the passage cells pass water passes into the xylem cells. Through the xylem tubes, the water moves up through stem xylem to leaf xylem. The root hair, passage cells and xylem cells are in a line to faciliate easy movement of water. The water movement from one cell to another is brought about by target

External Environmental factors

1) Available Soil Water

2) Concentration of soil solution

3) Soil temperature and Soil aeration

Internal Environmental Factors

1) Transpiration

2) Absorbing root system

3) Metabolism