Q. Name the principal body heat regulating centre in our brain?

Q. Why is ice lighter than water?

Q. How is air useful for us?

Q. Write any three differences between a plant cell and an animal cell.

Q. When do the desert plants take up carbon dioxide & perform photosynthesis?

Q. What is the void space of an FCC unit cell?

Q. Very Short Answer Type Question.Distinguish between biotic and abiotic environment with examples.

Q. What is fundamental theorem of arithmetic ?

Q. Define the term management.

Q. The 18th century France witnessed the emergence of the middle class. Who were they and what were their ideas?