What is and allele I need help pls

one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.

Explanation:

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.