Science Worksheet (Set 11)

Topic: Respiration

a. Name the process through which all organisms break down sugar to release energy.

Cellular respiration

b. Name the substance responsible for causing cramps in humans.

Lactic acid

c. Name the muscular floor of the chest cavity.

Diaphragm

d. Who guards the trachea so that food particles do not enter it?

Epiglottis

e. Name the special substance in the blood that binds with oxygen.

Hemoglobin

a. Difference between active and passive transport?

Active Transport	Passive Transport
Moves molecules against the concentration gradient.	Moves molecules along the concentration gradient.
Requires energy (ATP used).	No energy required.
Example: Mineral absorption in roots.	Example: Gas diffusion in lungs.

b. What does the lime water test indicate?

It turns milky, indicating the presence of CO₂ in exhaled air.