Question

Ethylene is a
A. Gaseous hormone
B. Gaseous enzyme
C. Solid hormone
D. Liquid gas mixture

Answer 1

Ethylene is a plant hormone. A plant hormone is a chemical substance that aids in the growth and maintenance of the plant. Ethylene is used in inducing the ripening of fruits and for the production of more fruits and flowers. It is a colorless flammable hydrocarbon having formula ${{C}_{2}}{{H}_{4}}$. During stogie of fruits, one ripened fruit can cause others to ripen due to the spread of ethylene.

Complete answer: Plant hormones are a class of chemicals that acts as messengers or signaling molecules that control plant growth and maintenance. There are many plant growth hormones namely auxins, gibberellins, cytokinins, etc. Ethylene is also a plant hormone. It functions to produce more flowers and fruits in the plant. Also, ethylene has a major role in the ripening of the fruits. Ethylene is a colorless gas with a sweet and musky odor. It is a small hydrocarbon that is flammable in nature. It is used in various chemical industries and agricultural practices. Fruit ripening, seed germination, etc. are induced by the application of ethylene. In natural plant life, ethylene is released only in trace amounts. This regulates the opening of flowers and the shedding of leaves. Chinese used this characteristic of ethylene to fasten the ripening of fruits by burning incense in a closed room. Ethylene also helps in the determination of the sex of the flowers.
So, the right answer is option A.

Note: Ethylene has various functions despite fruit ripening. Ethylene has an important function in growth like stimulating horizontal growth of the axis. In the longitudinal direction, ethylene inhibits growth. Also, ethylene speeds up the senescence in flowers and leaves. Ethylene lamps are used for the ripening of fruits like apple, mango, banana, etc. Also, as ethylene is gaseous it spreads readily from one ripened fruit to another.