CBSE Class 10 Science 2022 · Paper 31/3/3 · Question 15

(a) Leishmania; it causes kala-azar. (b) Bryophyllum produces buds in the notches along the margin of its leaves, and when a leaf falls on the soil these buds develop into new plants (vegetative propagation). A banana leaf bears no such buds, so it cannot give rise to new plants. (c)(i) Budding in Hydra: a bud develops as an outgrowth due to repeated cell division at one specific site on the body. The bud grows into a tiny individual with its own tentacles while still attached to the parent, and when fully mature it detaches from the parent body and becomes a new, independent Hydra. OR (c)(ii) (I) The mature Spirogyra filament simply breaks up into smaller pieces, or fragments, and each fragment grows into a new individual (fragmentation). (II) When a mature sporangium of Rhizopus bursts, the spores inside it are released; protected by thick walls, they grow into new Rhizopus individuals when they come into contact with a moist surface (spore formation).