The length of the small intestine in a human adult is about: (in $\text{ m}$)

What is the name of the cells in the leaf of a plant that control the opening and closing of stomata?

Which enzyme or substance is responsible for the conversion of milk into curd?

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

$(a)$ State two functions of bile juice.
$(b)$ Differentiate between the functions of enzymes pepsin and trypsin.

Represent the equation of photosynthesis. Explain the steps involved in photosynthesis. In which way are the steps of photosynthesis different in desert plants?