2.
which describes a selectively permeable membrane?

allows only certain substances to pass through

allows large quantities of every substance to pass through

permits only certain substances to leave but all to enter

permits all substances to pass through in small quantities

Allows only certain substances to pass through it. it also fences many substances inside it.

the calvin cycle has three stages. in stage 1, the enzyme rubisco incorporates carbon dioxide into an organic molecule. in stage 2, the organic molecule is reduced. in stage 3, rubp, the molecule that starts the cycle, is regenerated so that the cycle can continue

. ph changes the ability of them he enzyme to dissolve in water.