Final answer:
No, a genetic code based on only two bases cannot represent 20 amino acids. A two-base code creates 16 codons, not enough for 20 amino acids, whereas the real genetic code uses four bases and three-nucleotide codons, allowing for 64 unique codons.
Step-by-step explanation:
The question you've asked is whether a genetic code accommodating 20 different amino acids could be based on just two bases in four-base codons. The answer is No, a code based on two bases cannot adequately represent 20 amino acids. If we had only two different bases to work with, we could generate a maximum of 16 unique codons with a two-base code (42 = 16), which isn't enough for the 20 amino acids.
However, with a four-base code, even if it only used two types of bases, there would be 256 possible codons (44 = 256), which is more than enough to specify 20 amino acids. But, in reality, the genetic code uses three nucleotides per codon and all four types of bases, allowing for 64 unique codons (43 = 64), more than enough to code for the 20 amino acids found in proteins.
There are 20 common amino acids in proteins, and they are encoded by a series of three nucleotide bases called codons. With four bases forming three-base codons, there are 64 possible codons. This is more than enough to code for the 20 amino acids, so some amino acids are encoded by multiple codons.