Why are all of us considered scientists to some extent

Astructure that is found in a plant cell and not in an animal cell is a ? central vacuole mitochondrion nucleus ribosome

In dna, only the_ varies from one nucleotide to another. base phosphate sugar amino acid

Which way do the nitrogenous bases in dna pair up? a. a and g; t and c b. a and c; t and g c. a and t; g and c d. a and a; t and t; g and g; c and c