3 What happens to certain nutrient molecules after they pass into muscle cells?
(1) They are replicated in the nucleus.
(2) They are acted on by enzymes and release the energy they contain.
(3) They are changed into tissues and organs in the cytoplasm.
(4) They enter chloroplasts, where they can absorb light energy.
4 A medical test indicates that a patient has a defective protein. This
condition is most likely due to a change in the directions coded in the
(1) number of hydrogen atoms in starch molecules
(2) sequence of inorganic molecules
(3) number of carbon atoms in sugar molecules
(4) sequence of subunits in DNA
5 If a human system fails to function properly,
what is the most likely result?
(1) a stable rate of metabolism
(2) a disturbance in homeostasis
(3) a change in the method of cellular respiration
(4) a change in the function of DNA