Question

Ethylene is related with

A. Aerobic respiration

B. Climacteric phenomenon

C. Anaerobic respiration

D. Fermentation

Answer 1

Hint: There are various types of plant growth hormone present which affects the growth rate of plants. Some of the plant growth regulators are auxin, cytokinin, ethylene, ABA, etc. Ethylene is the only gaseous plant hormone.

Complete answer: 

The ethylene helps in the fruit ripening process. During the ripening, the rate of cellular respiration increases. This sudden, accelerated rise in the rate of respiration, during the ripening, is known as the climacteric rise. Due to this, the fruits which become yellow after ripening are known as the climacteric fruits. After ripening the fruit falls because ethylene promotes the formation of the abscission layer and increases the senescence.

Thus, ethylene helps in the climacteric phenomenon.

Hence, option (B) is correct.

Additional Information: 

There are some other physiological effects of ethylene too. The other physiological effects of ethylene are –

- Ethylene promotes flowering in mangoes and pineapples. In pineapples, it also helps in synchronized flowering.

- Ethylene also promotes the seed germination process by breaking the dormancy.

- Lastly, it promotes horizontal growth and reduces the longitudinal growth in stems and roots.

Note: Ethylene was first established as a plant hormone by Burg. It is commonly known as the ‘fruit ripening hormone’. Chemically it is C₂H₄. In the layman language, we also know it by the name of carbide. This hormone is used maximum in agriculture. It is important for us to note that ethylene is the only hormone that is present in the gaseous form at room temperature.