Which of the following statements is a correct distinction between autotrophs and heterotrophs?
a. autotrophs, but not heterotrophs, can nourish themselves beginning with co2 and other nutrients that are inorganic.
b. only heterotrophs require chemical compounds from the environment.
c. cellular respiration is unique to heterotrophs.
d. only heterotrophs have mitochondria.

a. Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic.

or

b. Only heterotrophs require chemical compounds from the environment.

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.

where in your body is there an enzyme that does function at a high or low ph? what is the name of that enzyme and its function?