Question

A tuft of hair present at one or both ends of the seed (for dispersal) is known as
A. Propeller
B. Samaroid
C. Pappus
D. Wings

Answer 1

The movement, dispersion, or transfer of seeds away from the parent plant is known as seed dispersal. Plants have limited mobility and must rely on a range of dispersal vectors to move their propagules, including both abiotic (like the wind) and living (like birds) vectors. Seed dispersal patterns are largely governed by the dispersal method, which has substantial implications for plant population demographics and genetic structure, as well as migration patterns and species interactions.

Complete answer:
Option A: Propeller is a collection of hair placed at one or both edges of the seed (for dissemination). The wing has a small pitch (similar to that of a propeller or fan blade), and the one-winged propeller type found in maple is known as a samara.
Hence, option A is correct.
Option B: A samara is a winged achene, a form of fruit in which the ovary wall produces a flattened wing of fibrous, papery tissue. A samara is a basic dry fruit that does not decompose. The form of a samara allows the wind to carry the seed further away from the parent tree than normal seeds. The seed can be in the middle of the wing or on one side, with the wing extending to the opposite side, causing the seed to auto rotate as it falls.
Hence, option B is incorrect.
Option C: In flower heads of the plant family Asteraceae, the pappus is a modified calyx, a component of an individual floret, that surrounds the base of the corolla tube. Although such structures are not produced from the flower's calyx, the word is frequently applied to comparable structures present as a wind-dispersal mechanism for seeds of genera in other plant families, such as certain genera of the Apocynaceae.
Hence, option C is incorrect.
Option D: Winged seeds can be disseminated over great distances by hydrochory after being spread by anemochory. The seed wing has little function in water absorption and none in seed moisture retention, but its presence enhances soil adherence to the seed.
Hence, option D is incorrect.

Therefore, Option A is the correct answer.

Note:
Seed dispersal is believed to be beneficial to a variety of plant species. For starters, seed survival is often higher when the parent plant is removed. The actions of density-dependent seed and seedling predators and diseases, which frequently target the high numbers of seeds beneath adults, may be the cause of this increased survival.