Changes in one of the factors of the environment may cause decline and extinction. a. chemical b. physical c. both a and b d. none of the above

Which of the following structures is not found in both plant and animal cells? a) chloroplast b) cytoskeleton c) ribosomes d) mitochondria

This is an active transport mechanism by which cells pump sodium and potassium ions against the concentration gradient

You are studying a protein that you call protein x. there is an aspartic acid at a key position in protein x which is important in the folding and stabilization of that protein. if this aspartic acid is changed to a different amino acid, which type of amino acid substitutions is most likely to allow the protein to fold normally?