Answer D) : from testing the starch by iodine
Answer:
5 bases
Explanation:
If there are 17 amino acids and only 2 bases that can be combined in order to make a codon then:
for 4 bases 
is 16 and it is not enough combination for all 17 amino acids
for 5 bases 
is 25 combinations (meaning that more than one codon could code for the same amino acid).
The answer would be c. plant trees around farmland. This is because the trees will protect the soil from being affected by the wind.
