THE MOLECULAR BASIS OF INHERITANCE
DNA MAKES RNA MAKES PROTEIN
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
Some codons do not specify an amino acid.
|
|
|
Some codons have the same sequence of nucleotides.
|
|
|
The codon AUG codes for the amino acid methionine and serves as the “start” codon for protein synthesis.
|
|
|
There are 64 different kinds of codons but only 20 amino acids.
|
Detailed explanation-1: -Of these 64 codons, 61 represent amino acids, and the remaining three represent stop signals, which trigger the end of protein synthesis. Because there are only 20 different amino acids but 64 possible codons, most amino acids are indicated by more than one codon.
Detailed explanation-2: -Because DNA consists of four different bases, and because there are three bases in a codon, and because 4 * 4 * 4 = 64, there are 64 possible patterns for a codon. Since there are only 20 possible amino acids, this means that there is some redundancy–several different codons can encode for the same amino acid.
Detailed explanation-3: -The number of potential triplets is 64. Subtracting for a necessary stop codon, organisms could code for up to 63 different amino acids. One could argue that 20 is simply good enough, but several species use up to 22 residues to synthesize proteins.
Detailed explanation-4: -There are a total of 64 codons in the genetic code arising from the permutation and combination of the 4 bases in nucleic acids. The genetic code is degenerate i.e. more than one codon can code for a single amino acid. Due to this, of the 64 codons, 61 codons code for the 20 amino acids.
Detailed explanation-5: -Because amino acids can be arranged in many different combinations, it’s possible for your body to make thousands of different kinds of proteins from just the same 21 amino acids.