How would pepsin activity be affected if it were put in a neutral solution?

The rate at which molecules water and oxygen can enter a cell is determined by the-

Why do we perceive objects as retaining their brightness under different lighting levels?

What does polymerase chain reaction (pcr) do? o a. separates dna fragments by size o b. cuts a dna sample into fragments o c. provides an overall picture of a person's chromosomes o d. makes more copies of a sample of dna