CBSE Class 10 Science 2020 · Paper 31/4/3 · Question 28(b)

(a) Vegetative propagation is a mode of asexual reproduction in which new plants develop from the vegetative parts of a plant, such as the root, stem or leaf, instead of from seeds. Advantages: (1) the plants bear flowers and fruits earlier than plants raised from seeds; (2) many plants identical to the parent, with all its characters, can be raised; (3) it is the only way to propagate plants that have lost the capacity to produce seeds, such as banana, orange, rose and jasmine. Methods: layering and grafting (cutting is another). (b) More complex organisms have a very high level of differentiation and organisation: specialised cells make up tissues, tissues make up organs and organs make up organ systems, each placed at a definite position in the body. Because their cells are so specialised, their tissues and organs have lost the ability to regenerate a whole body; a cut part contains only a few kinds of cells and cannot form all the other tissues and organs in their places. Hence they cannot give rise to new individuals from their cut body parts by regeneration.