How is carbon dioxide obtained by: $(i)$ Aquatic plants. (ii) Terrestrial plants?

Define enzyme. Name one enzyme in humans which digests fats.

Name the stored food of animals.

Why does absorption of digested food occur mainly in the small intestine?

In the following questions, a statement of Assertion is given followed by a statement of Reason. Mark the correct answer as:
Assertion: Nutrition in $Amoeba$ takes place with the help of $pseudopodia$.
Reason: Different stages of nutrition in $Amoeba$ are ingestion, digestion, absorption, and egestion.

Name the two glands associated with the digestive system in humans. Name their secretions also.