Question

Seed dispersal in plants takes place by
I. Wind
II. Water
III. Birds
A) I only
B) III ONLY
C) I and II
D) I and III only
E) I, II and III

Answer 1

Hint: Seed dispersal is an adaptive mechanism.Seed dispersal is the movement, spread or transport of seeds away from the parent plant. There are types of seed dispersal.

Complete answer:
Seed dispersal is a method that is used to develop new plants from the older one. It actually helps the plants to grow in other places that enhance its growth. As the plants are not movable the new plants will compete with older ones and vice-versa leads to improper growth. This also leads to less competition among them so proper sunlight, minerals and water can be acquired by the plants. There are various methods through which the plants disperse their seeds.

Now let us look into the types of seed dispersals:
i) By Wind- This method is very common in those plants that have non-sticky and light weighted pollen grain. The stamens are also long in these plants so that it can easily expose the pollens and therefore the wind can carry it.
ii) By Water- It is found mostly in the monocots and the plants that grow near the water area. The water pollinated species generally have the mucilaginous covering above the pollen grains so that it can survive in water and help it to fertilize the female gamete.
iii) By Birds-The birds generally feed on the seed and the dispersal of seed happens by birds drooping as well as in some cases when the bird takes seed from one place to another and it gets dropped which leads to growth of new plants. So, the seed dispersal occurs with all the methods that are by wind, water and birds.

Hence the correct answer is option ‘E’.

Note: The time up to which the seed is viable has a very wide range; some can live for many years and some are viable for a few months only. The oldest seed viability example is Lupine that has a record of ten thousand years of dormancy.