Question

A tuft of hair present at one or both ends of the seed (for disposal) is called
A) Propeller
B) Coma
C) Pappus
D) Wing

Answer 1

Hint:-Various factors both living and non-living help plants disperse their seeds. When seeds get dispersed they are transported to far-off places and have a higher chance of surviving. The seeds can be dispersed by wind, birds, and animals, etc. Sometimes seeds have certain modified features that help in its dispersal.

Complete solution:
● In the wind, certain seeds have a tornado-like motion.
● This is due to certain modifications in the seed and such seeds are known as propellers.
● Green ash and tree of heaven are plants that produce these propeller seeds.
● Ends of certain seeds and fruits have tufts of hair present on them, this is known as the coma.
● The presence of hair at one end or both helps in the seed dispersal.
● The seed can cling to the fur of an animal or be carried away by the wind.
● This dispersal is seen in plants of the milkweed family.
● Pappus actually is a modified calyx (a collection of sepals), found in the Asteraceae family.
● This can be in the form of bristles like in the case of dandelions.
● The feathery bristles surrounding the dandelion seeds help in dispersal.
● Modifications that result in the formation of certain wing-like structures in the seeds facilitate its dispersal.
● The plants do not have to depend on animal or bird intervention. Maple seeds have such modifications.
So, the correct answer is option B.

Note:- The dispersed seed has to adapt to the new environment to survive. This could help in the evolution of the plant. When humans, on purpose, intervene to facilitate seed dispersal it is known as seed bombing. If this is done without proper research the seed may not survive in its new environment.