Although they were once classed together, archaea and bacteria have now been separated into two different domains. why was this change necessary?

a. the archaea only have cell membranes and the bacteria only have cell walls.
b. the two groups are composed of species with different cell sizes.
c. the archaea have nuclei and the bacteria do not.
d. the two groups replicate their dna in different ways.

Two groups replicate their DNA in different ways.

Explanation:

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.

a) carbon, hydrogen

b) carbon, hydrogen, oxygen, nitrogen

c) carbon, hydrogen, oxygen, nitrogen, phosphorus

d) sugar

e) amino acid

f) nucleotide