Name the organelle in which photosynthesis occurs.

Name any two digestive enzymes secreted in the human digestive system and write their functions.

Liver is the largest organ as well as the largest gland of the body.

Explain holozoic nutrition.

Single circulation,i.e.,blood flows through the heart only once during one cycle of passage through the body,is exhibited by:

$(a)$ Bile does not contain any digestive enzyme,yet it is important for the digestion of food. Why?
$(b)$ Name the products formed after the complete digestion of carbohydrates,proteins,and fats in the small intestine.