(a) Draw a diagram of the longitudinal section of a flower and label on it sepal, petal, ovary and stigma.

(b) Write the names of male and female reproductive parts of a flower.

OR

(a) What is fragmentation in organisms? Name a multicellular organism which reproduces by this method.

(b) What is regeneration in organism? Describe regeneration in Planaria with the help of a suitable diagram.

Part (a) Longitudinal Section of a Flower

Below is the schematic diagram of the longitudinal section of a flower showing the key parts:

Part (b) Reproductive Parts of a Flower

• Male Reproductive Part: Stamen (consists of anther and filament). It produces yellowish pollen grains.
• Female Reproductive Part: Pistil or Carpel (located in the center, consisting of stigma, style, and ovary).

OR

Part (a) Fragmentation

• Definition: In multicellular organisms with relatively simple body organisation, the body simply breaks up into smaller pieces upon maturation. These pieces or fragments then grow into new individuals.

Example: Spirogyra*.

Part (b) Regeneration

• Definition: The ability of fully differentiated organisms to give rise to new individual organisms from their body parts if they are cut or broken into pieces.

Regeneration in Planaria: If a Planaria* is cut into multiple pieces, specialised cells at the cut sites proliferate rapidly to form a mass of cells. These cells undergo changes in an organised sequence (development) to form different cell types and tissues, eventually regenerating complete missing body parts to form new individuals.