A filamentous alga X is found in ponds, lakes and slow-moving streams. The filament of this alga simply breaks into two (or more) pieces on maturing and each piece then grows. to become a complete new alga.

(a) Name an alga which X is likely to be.

(b) What is the colour of X?

(c) What is the method of forming new algae by the breaking of parent alga known as ?

(d) An Amoeba also breaks up to form two. daughter Amoebae. What is the difference in the splitting Amoeba and splitting of this alga as a method of reproduction ?

(e) Name one marine animal which reproduces in the same way as alga X.

A worm X found in freshwater and slow-moving streams has been accidently cut into three pieces. It was observed that in due course of time, each cut piece of the worm develops to become a complete worm by growing all the missing parts.

(a) Name the worm X which can exhibit this phenomenon of making complete worm from its cut body parts.

(b) Name another organism Y which possesses the same characteristic of growing fully from its cut body parts.

(c) What is the name of this process in which a complete organism is formed from its cut body part.

(d) State whether X and Y are unicellular and/or multicellular organisms.

(e) Can a dog be produced completely from its cut body part (say, a cut tail) just like organisms X and Y ? Why?

A thickened underground stem X of a plant which is swollen with stored food has a number of points Y on its surface. When the old stem X is planted in the soil of a field in the next growing season, then each point Y present on its surface grows into a new plant.

(a) What is the general name of the underground stems like X?

(b) Give one example of X.

(c) What are points Y present on X known as?

(d) Is it necessary to plant the whole of stem X in the ground to obtain its new plants? Explain your answer.

(e) What is the name of this method of reproduction of plants?

(f) What is the advantage of growing new plants from the underground stems like X ?

When a broken piece of the stem of a plant X is planted in the soil, a new plant grows from it in a week' time. The leaves of plant X also have many small entities Y in their margins which can fall to the ground alone or alongwith leaves and grow into new plants.

(a) Name a plant which X could be.

(b) What are the entities Y present on the leaves of X known as?

(c) Name a plant other than X which can be reproduced from its leaves.

(d) Name a common plant grown in many homes which can be propagated from its broken stems like plant X.

(e) Name a kind of dormant organs present in dry stems of old grass plants lying in the fields which activated and produce green grass plants after the rains.

Where are a plant's sex organs located?