Reproduction in Plants — Science STD 7 — Question

Wind, water, animals, birds and humans are the dispersing agents of seeds. These are described below 
(i) Wind The seeds that are very light and have wing or hair-like structure on them, are easily carried away by the blowing wind, e.g. seeds of maple, drumstick have wings, seeds of madar or oak have hairs on them, while seeds of grasses are very small and light. These seeds can be easily carried away by the wind and dispersed away from their natural habitat, e.g. hairy fruit sunflower.



(ii) Water The seeds of some plants that have an outer fibrous or spongy covering are dispersed through water. They have the ability to float in the water and drift along with its flow, e.g. coconut.
(iii) Animals Some seeds have hooks or spines which get attached to the fur or body of animals. When these animals move to a distant place the seeds get dispersed (while animal rub their body surface), e.g. Xanthium and Urena plants.

(iv) Bursting of Fruits Sometimes fruits mature and a strain is produced in their walls. This produces a sudden jerk causing fruits to break open, thus allowing the seeds to scatter far away from their parent, e.g. castor and balsam.