1. Give two examples of unicellular plants.

2. Name two cells which continuously change their shape.

3. Why a cell wall is present in a plant cell but absent in an animal cell?

4. What is meant by ‘division of labour’ in multicellular organisms?

Dear Student

Ans 1. Examples of unicellular plants include algae such as Chlamydomonas and Chlorella.

Ans 2. Examples of cells that continuously change shape are:
• White Blood cells (WBC's)
• Amoeba

Ans 3. Cell wall is a tough and rigid layer around the cell of certain organisms like plants and bacteria, which provides structural support and protects the cells. It is not necessary for animal cells to have a cell wall due to a various reasons like,  

 1) Animal cells have other forms of support like exoskeleton and endoskeleton. While plant cells do not have these, so they require cell wall.

 2) Animal cells can regulate osmotic pressure by pumping ions and salts across the cell membrane. So, they do not require cell wall to protect themselves from bursting due to endosmosis.  

 3) Animal cells require flexibility for function and movement. This would not be possible if cells have cell wall as it would restricts flexibility. 

P.S. For the rest of the questions, kindly post them in a separate thread.

Regards