1. Cattle that feed on grass occupy which trophic level?
     
first
second
third
fourth

2. A lion eating a gazelle is an example of

an organism at the thirdtrophic level.
predator/preyinteraction.
part of the niche of thegazelle.
All of the above aretrue.

3. Different forms of the same gene are referred to as

loci.
alleles.
homozygotes.
hybrids.

4. How many common amino acids are used in proteinsynthesis?

14
20
30
64

5. There are three different forms of RNA. Which is not one ofthese?

mitochondrial
messenger
transfer
ribosomal