Tutor profile: Keabetswe K.

Explain how the types mutations that lead to cancer are different for a proto-oncogene and a tumor suppressor gene?

A cancer-causing mutation in a proto-oncogene usually makes the cancer gene product overactive,whereas a cancer-causing mutation in a tumor-suppressor gene makes the cancer gene product nonfunctional.

What type of chemical reaction occurs faster at equilibrium,the formation of products from reactants or reactants from products?

At equilibrium,the forward and reverse reaction occur at the same time.

Humans have two types of photoreceptor cells.Name and give a brief explanation of the two types of photoreceptors.

Rods-are more sensitive to light but do not distinguish colors;they enable us to see at night,but only in black and white. Cones-provide color vision,but being less sensitive and contribute very little to night vision.