Active transport requires energy when moving molecules against a concentration agent. It requires for specific membrane transport proteins. Only a certain type of protein can move a certain type of substance.
The three main types of Active Transport are:
1) Sodium-Potassium Pump
2) Endocytosis
<span>3) Exocytosis </span>
I would say c would be the best.
A single gene could be inserted into a plant's genome, enabling specific traits to be expressed easily. Scientists have identified genes for two enzymes needed to make pro-vitamin A. One of these genes comes from corn.
