M.Sc. (Botany) (Semester-IV) (CBCS) Examination, 2017
ENVIRONMENTAL PLANT PHYSIOLOGY
Day Date: Monday, 24-04-2017 Max. Marks: 70
Time: 02.30 PM to 05.00 PM
N.B. Attempts totally five questions.
Q.1 is compulsory.
Attempts any two questions from Q.2 to Q.4
Attempts any two questions from Q.5 to Q.7.
Figures to the right indicate full marks.
Q.1 Write the correct answer from given alternatives. 14
Hydroxyl ions are harmful because they cause
Decrease in chlorophyll content
Increase in RNAase
Peroxidation of membrane lipids
Inactivation of RUBISCO
An exposure to UV radiations stimulates synthesis of in plants.
Phenols Proline
Anthocyanins Chlorophylls
There is a deficiency of in the waterlogged soils.
Oxygen CO2 P
Nutrients All the above
Accumulation of glycine betaine is observed in some crops in
response to
Water stress Flooding P
Pollution stress All of these
Following is the main target of chilling stress
Strach Phospholipids I
Proteins Chlorophylls
Following enzyme plays an important role in the development of
arenchyma in wetland species
Cellulose Peroxidase I
Chitinase Pectinase
Electrical conductivity of typical saline soil is
Less than 4ds More than 4ds I
Equal to zero Not measurable
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Chilling injury occurs when warm region plants are exposed to a
temperature of
I

In frost injury, ice formation begins at
Freezing point
Several degrees below freezing point
Slightly above the freezing point

10) Disease occurs in the plants when the pathogen lacks
R genes Avr genes N
DIRI genes None of these
11) Slat glands are present in halophytes showing Phenomenon.
Salt evasion Salt tolerant N
Salt insensitive All of these
12) Elevated CO2, concentration causes
Increase in photosynthesis Decrease in photorespiration V
Increase in WUE All of these
13) CaSO4 is used for reclamation of Soil.
Acidic Alkaline V
Saline Marshy
14) is not a compatible solute.
Proline Glycine-betain N
Sorbitol Malic acid
Q2 Give an account of effect of salt stress on plant metabolism. 07
Write a note on mechanism of salt tolerance in higher plants. 07
Q3 Describe in brief:
Effects of water stress on plant metabolism. 07
Structural adaptations in xerophytes in response to water stress. 07
Q4 Describe the role of essential heavy metals in plants. 07
Explain effects of heavy metal toxicity and the resistance
mechanism.
07
Q5 Explain the effects of visible and UV radiations on plants. 07
Add a note on the mechanism of UV tolerance. 07
Q6 Write on:
Effect of on plant metabolism. 07
Mechanism of flooding tolerance. 07
Q7 Write short notes on (any three): 14
Mechanism of disease resistance
Allelochemicals
Mechanism of heat and cold tolerance
Antioxidants.