What is the relationship between a nucleotide and a nitrogen base? A nucleotide contains a nitrogen base.
A nucleotide is a pair of nitrogen bases.
A nucleotide and a nitrogen base are the same thing.
A nitrogen base contains a nucleotide.

(drag each tile to the correct identify which questions can be answered by what can be answered by science or which cannot. -is it right or wrong to use genetic engineering to produce new food products? -what are the most common social settings that tend to produce accomplished artists? -if a new gene is added to the genome of a tomato species, will that species be more resistant to insects? -should humans use biotechnology to bring extinct organisms from the fossil record back to life? -do the types of organisms found in the fossil record appear in consistent sequences in different parts of the world? -are michelangelo's paintings more impressive than rembrandt's?

All but one describes an effect of aging on the digestive system. a) decreased acid secretion b) decreased elasticity of stomach c) capacity to resist damage decreases d) food remains in stomach for less time

Which of the following is a reason why early living organisms on earth could not have survived on the surface? 1. the lack of an ozone layer 2. the lack of oxygen in the atmosphere 3. the fact that these organisms were single-celled