1. why are the pollen grains of grasses light and produced in large quantities ?
2. name two plants which give rise to new plants from their swollen roots .
3. name a crop plant that is multiplied by steam cuttings .
4. what is fertilisation ?
Answers
1) Pollen grains of wind-pollinated flowers are produced in large quantities to make sure that at least some pollen grains reach the stigmas of other flowers and successful pollination takes place as many pollen grains are wasted. These pollen grains are light and hence are easily transferred to other flowers.
2) Tuberous roots of Dahlia, sweet potato, Asparagus become swollen due to stored food material and can give rise to new plants.
3) Foliage shrubs like Golden Duranta, Acalypha, Crotons; Kitchen herbs like Rosemary, Thyme, Mint etc. Apart from these many herbaceous annuals, climbers and creepers, and hedge plants and many flowering trees like Gliricidia can be grown by stem cuttings.
4) Fertilisation or fertilization, also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development