Answer: The option that is not true is D) Each amino acid is specified by only one codon.
Codon can be defined as the sequence of three nucleotides ( present in DNA or mRNA) that corresponds to a particular amino acid. It helps in the process of translation as different amino acids ( that are linked to codons) are assembled to give a particular protein according to the sequence of codon.
There are 64 codons and 20 amino acids that make up the proteins present in the living systems. This indicates that several different codons can correspond to the same amino acid.
For instance, amino acid Valine is coded by four codons that is GUC, GUG, GUA, GUU.
Thus, option D) is incorrect.
Answer:
He will use a radioactive element with a long half life of greater than 1 billion years
Explanation:
Rocks are an aggregation of solid mass which is usually rich in minerals. The age of rocks is established using radiometric dating method.
According to Oxford Dictionary, radiometric dating is "a method of dating geological specimens by determining the relative proportions of particular radioactive isotopes present in a sample."
The age of rocks can only be ascertained using isotopes that have very long half lives because many of these rocks are very old (aged billions of years) hence their age can only be determined using elements that has a half life greater than 1 billion years.
