Examples of adaptation for spreading seeds?

Answer 1

Well the first thing to look at is what agents or vectors can possibly move seed away from a plant, by identifying those you can suggest what structures or adaptations are required to facilitate this - these would be things that occur naturally in "the wild":

Wind, Water, Animals/ Insects, Hooks and possibly fire.

Wind. The seeds need to be light or have adaptations such as wings or "parachutes" to enable the seed to travel away from the parent plant. A common example is the Dandelion plant that has a fine hairlike parachute which can cause it to be carried kilometres from the parent.

Water. Generally speaking live seeds tend to be heavier than water so they sink; and adaptation to enable the seed to float can be seen in the coconut. The seed is large and is empty of fluid when ripe, this displaces water and the seed floats. Again these seeds can be transported hundred or even thousands of kilometers by rivers and the sea.

Animals and insects are normally attracted to seeds through the tasty fruit they provide. The fruit is eaten and digested by the animals normally some distance from the tree. Seeds of these fruits normally have hard seed coating to prevent them being digested by stomach acids. The seeds are then passed through the animals and land on the ground where they germinate.

Hooks. Some seed are produced with small hooks or barbs on them, these are then caught in the fur of animals as they pass close to the plant; this will also happen where people walk close to the plant and the seeds are caught in their clothes. An example would be thorns that you may find in grass, these are sometimes seed with hooks that get caught in the feet, hooves or pads of animals (and people) as they pass over them.

Fire. While fire is not specifically an agent of dispersion is does sometimes aid dispersion. There are certain groups of plants who's seed will only germinate once exposed to fire (Protea's are an example), the seed is hard and woody and is normally dormant in the soil. Once a fire has swept over the area (and the competitive plants killed), the seed dormancy is broken, the tough seed coat will also be either partially burn or be cracked open by the fire allowing the seed to germinate.

Answer 2

well u see....