There are sixty-one codons that each specify the addition of a specific amino acid, and three stop codons for which there is no corresponding amino acid. However, there are only about forty tRNA molecules, representing forty anticodons
How is that possible?
A) Only about forty of the recognized sixty-one codons are present in mRNA.
B) An anticodon forms hydrogen bonds with the codon; it must match the first two bases of the codon, but is less specific with respect to the third base.
C) There are tRNAs that can bind one of two related amino acids.
D) Only twenty of the codons are activeâ€"one for each amino acid.
Answer: B
You might also like to view...
If an allele is dominant in one sex and recessive in another, it is an example of ___________
A. sex-limited inheritance B. sex-influenced inheritance C. incomplete dominance D. simple Mendelian inheritance
Scientists have demonstrated that the cholera bacteria, Vibrio cholerae, can exist as a rather harmless form or, by phage conversion, can exist as a disease-causing, virulent form. This conversion is caused by
A. the phage entering the cholera bacterium genome and causing the bacterium's cell to lyse. B. the phage introducing a gene into the bacterium's chromosome that codes for the cholera toxin that can cause death in humans. C. the phage altering the cell wall of the cholera bacterium that produces a toxin that can cause death in humans. D. the phage alters the host cell, which permits direct entry of the cholera bacterium into the host cell leading to death in humans.
The concept that a set of three nucleotides specifies a particular amino acid provides the basis for
A) the one-gene-one-enzyme hypothesis. B) the one-gene-one-polypeptide hypothesis. C) the genetic code. D) biochemical reactions among nucleic acids. E) All of these
The process used to control the level of water and ions in body fluids is termed
What will be an ideal response?