The osmotic expansion of a cell kept in water is chiefly regulated by:

1. Mitochondria

2. Vacuoles

3. Plastids

4. Ribosomes

During which phase(s) of the cell cycle, amount of DNA in a cell remains at 4 C level if the initial amount is denoted as 2C:

1. G₀ and G₁

2. G₁ and S

3. Only G₂

4. G₂ and M

Match the following and select the correct answer: 

1. A-iv, B-ii, C-i, D-iii

2. A-i, B-ii, C-iv, D-iii

3. A-i, B-iii, C-ii, D-iv

4. A-iv, B-iii, C-i, D-ii

Dr. F. Went noted that if coleoptile tips were removed and placed on agar for one hour, the agar would produce a bending when placed on one side of freshly - cut coleoptile stumps. What is the significance of this experiment?
 

Deficiency symptoms of nitrogen and potassium are visible first in:

1. Senescent leaves

2. Young leaves

3. Roots

4. Buds

In which one of the following processes CO₂ is not released?

1. Aerobic respiration in plants

2. Aerobic respiration in animals

3. Alcoholic fermentation

4. Lactate fermentation

Anoxygenic photosynthesis is characteristic of:

1. Rhodospirillum

2. Spirogyra

3. Chlamydomonas

4. Ulva

A few normal seedlings of a tomato were kept in a dark room. After a few days, they were found to have become white-coloured like albinos, Which of the following terms will you use to describe them?

1. Mutated

2. Embolised

3. Etiolated

4. Defoliated

Which one of the following growth regulators is known as the stress hormone?

1. Abscisic acid

2. Ethylene

3. GA₃

4. Indole acetic acid

Geitonogamy involves: