Water can move through the soil-plant-atmosphere continuum, only if water potential (ψ_m) along that path

• Decreases

• Increases

• Remaind unchanged

• Fluctuates rapidly in either direction

In the global nitrogen cycle, the following microbial organisms are involved in three important process – dinitrification, nitrification and nitrogen fixation.

(a) Rhizobium   (b) Nitrosomonas   (c) Nitrobacter   (d) Pseudomonas    (e) Azotobacter

Which of the following is the correctly matched pair of process and its causative species?

• Denitrification – (b); Nitrogen fixation – (c) and (e); Nitrification – (d)

• Denitrification – (d); Nitrogen fixation – (a) and (e); Nitrification – (c) 

• Denitrification – (e); Nitrogen fixation – (a) and (d); Nitrification – (d)

• Denitrification – (b); Nitrogen fixation – (a) and (d); Nitrification – (c)

Change in Ca²⁺ concentration can initiate various responses in plants. Which one of the following responses is NOT known to be initiated by change in Ca²⁺ concentration?

• Closure of stomata

• Reorientation of growth in pollen tubes

• Thickening of cell walls in young tobacco seedlings in response to wind

• Lateral root formation    

The citric acid cycle in respiration yields

• 1 GTP, 3 NADH, 1 FADH₂, 2 CO₂   

• 2 GTP, 2 FADH₂, 6 NADH, 2 CO₂  

• 4 GTP, 6 NADH, 4 FADH₂, 2 CO₂       

• 32 GTP, 2 NADH, 4 FADH₂ 4 CO₂

Chlorophyll pigment composition and carbohydrate food reserves of some algal groups are given below:

Pigments: (i) Chlorophyll a and b ; (ii) Chlorophyll a and c         

Carbohydrate food reserve: (a) Paramylon; (b) Starch; (c) Laminarin; (d) Leucosin.

Identify the correct combination of the characters for the given groups.

• Euglenophyta- (i and a); Bacillariophyta- (ii and d); Phaeophyta- (iii and c); Chlorophyta- (i and b).     

• Euglenophyta- (ii and a); Bacillariophyta- (ii and d); Phaeophyta- (i and c); Chlorophyta- (i and b).      

• Euglenophyta- (i and a); Bacillariophyta- (ii and b); Phaeophyta- (i and c); Chlorophyta- (ii and d).

• Euglenophyta- (i and d); Bacillariophyta- (ii and a); Phaeophyta- (ii and c); Chlorophyta- (i and b). 

Following are some statements about low temperature stress in plants.

A. Fatty acid composition of mitochondria isolated from chilling resistant and chilling sensitive plants differs significantly.

B. Ratio of unsaturated fatty acids to saturated fatty acids is lower in chilling resistant soecies.

C. The cellular water does not freeze even at -40°C, because of the presence of solutes and other antifreeze proteins.

D. Heat shock proteins do not play any role during low temperature stress.

Which one of the following combination of above statement is correct?

• A and B

• A and C

• B and C

• B and D

Use of doubled haploid in plant breeding helps to

• Reduce generation time while interogressing recessive traits.   

• Reduce generation time while intergressing dominant traits.

• Develop somatic hybrids

• Interogress transgenic traits

A plant hormone that promotes the acquisition of desiccation tolerance in developing seed is

• ABA

• Ethylene

• IAA

• GA3

Following are some statements for synthesis of jasmonic acid in plants

A. 12-oxo-phytodienoic acid is produced in chloroplast and transported to peroxisoe.

B. Action of lipooxygenase, allene oxide synthase and allene oxide cycylase takes place inperoxisome.

C. 12-oxo-phytodiconic acid is first reduced and then converted to jasmonic acid by β-oxidation.

D. Final production of jasmonic acid takes place in chloroplast.

E. Action of allene oxide synthase and allene oxide cyclase takes place in chloroplast.

Which one of the following of above statements is correct?

• A, B and C  

• B, D and E  

• C, D and E  

• A, C and E 

Following are statements related to the organization of the four major protein complexes of thylakoid membrane.

A. Photosystem II is located predominantly in the stacked region of the thylakoid membrane.

B. Photosystem I is found in the unstacked region protruding into stroma.

C. Cytochrome B₆ f complex is confined to stroma only.

D. ATP synthase is located in the unstacked regions protruding into stroma.

Which one of the following combinations of above statements is correct?        

• A, B and C

• A, B and D   

• B, C and D  

• C, D and A