The base found in RNA nucleotides, but not in DNA, is uracil.
RNA and DNA share three bases: adenine, cytosine, and guanine. However, for the fourth base, DNA has thymine while RNA
has uracil. When forming base pairs, cytosine bases are matched with guanine, while adenine bases are matched with uracil or thymine.
If an ecosystem has experienced a flood, small annual plants are the type of plants you can expect to see growing first after the flood.