Page 2 - 2.Lesson Notes -Sexual mode of reproduction IV

 However, plants cannot move from one place to another. So the seeds scatter
or disperse.

Agents for Seed Dispersal

Dispersal by Wind
Seeds of certain plants like dandelions, maple, and cottonwood trees are lightweight,
wings, and have hair. These seeds can be carried long distances by the wind.

Dispersal by water
 Seeds dispersed by water growing in or near water sources.
 Seeds are generally light and buoyant fruit, giving them the ability to float.
 Examples- Coconuts are well known for their ability to float by trapping air
between its fibres and to reach the land where they can germinate. Similarly,
the lotus produces a lightweight and spongy fruit that can float on water.

Dispersal by Animals

 Seeds can be dispersed by animals as well. Some seeds like Xanthium have
hooks or spines, by which they stick to the body of animals or clothes of
humans and thus carried away.
 Many birds and animals swallow the seeds while eating the fruit. However,
these seeds are passing undigested, through the digestive tract and get
dispersed when excreted out, thus germinating in different places.
 Humans also help in dispersing seeds. We eat fruit and throw away their
seeds. When some seeds fall on the ground and receive proper conditions,
they germinate.
 Some animals such as squirrels and mice also help in seed dispersal by
storing nuts in their burrows under the soil.

Dispersal by self-explosion

Fruits of certain plants such as Legumes, Castor, geranium, peas, and acacia burst
open forcibly after drying.