CBSE Class 10 Science 2019 · Paper 31/3/1 · Question 18(a)

(a) Reproduction is the process by which living organisms produce new individuals (young ones) of their own kind. Its two types are asexual reproduction and sexual reproduction. (b) Unicellular organisms reproduce by the division of their single cell - binary fission (Amoeba), multiple fission (Plasmodium) or budding (yeast): only one parent is required, it is a fast process, and no specialised reproductive cells are needed, as the whole cell divides. Multicellular organisms have bodies of cells organised into tissues and organs, so they cannot reproduce by simple cell division: sexual reproduction, common among them, requires two parents; reproduction is a slower process; and specialised reproductive cells, tissues or organs are needed - gametes formed in reproductive organs, or specialised cells and parts in asexual methods such as budding in Hydra, regeneration in Planaria and spore formation in Rhizopus.