Water vapour comes out from the plant leaf through the stomatal opening. Through the same stomatal opening carbon dioxide diffuses into the plant during photosynthesis. Reason out the above statements using the following options. 

1. Both process can happen together because the diffusion coefficient of water and CO₂ is different. 

2. The above processes happen only during night time

3. One process occurs during the day time and the other night

4. Both processes cannot happen simultaneously

A plant in your garden avoids photorespiratory losses, has improved water use efficiency, shows high rates of photosynthesis at high temperatures and has improved efficiency of nitrogen utilization. In which of the following physiological groups would you assign this plant?

(1) C₄

(2) CAM

(3) Nitrogen-fixer

(4) C₃

Emerson's enhancement effect and red drop have been instrumental in the discovery of 

(1) two photosystems operating simultaneously

(2) photophosphorylation and cyclic electron transport. 

(3) Oxidative phosphorylation

(4) photophosphorylation and non-cyclic electron transport

In a chloroplast the highest number of protons are found in

1. lumen of thylakoids

2. inter membrane space

3. antenna complex

4. Stroma

In photosynthesis, the light-independent reactions take place at 

1. thylakoid lumen 

2. photosystem l

3. photosystem ll

4. stromal matrix

Anoxygenic photosynthesis is characteristic of 

(1) Rhodospirillum

(2) Spirogyra

(3) Chlamydomonas 

(4) Ulva

The correct sequence of cell organelles during photorespiration is 

(1) chloroplast-Golgi bodies-mitochondria

(2) chloroplast-rough endoplasmic reticulum-dictyosomes

(3) chloroplast-peroxisome-mitochondria

(4) chloroplast-vacuole-peroxisome

PGA as the first CO₂ fixation was discovered in the photosynthesis of 

(1) bryophyte

(2) gymnosperm

(3) angiosperm

(4) algae

C₄ -plants are more efficient in photosynthesis than C₃ -plants due to 

1. higher leaf area

2. presence of larger number of chloroplasts in the leaf cells. 

3. presence of thin cuticle

4. lower rate of photorespiration

THe C₄ -plants are photosynthetically more efficient than C₃ -plants because

(1) the CO₂ compensation point is more

(2) CO₂ generated during photorespiration is trapped and recycled through PEP carboxylase

(3) the CO₂ efflux is not prevented

(4) they have more chloroplasts.