There Are 61 Codons That Each Specify the Addition of a Specific

question 32

Multiple Choice

There are 61 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 40 tRNA molecules, representing 40 anticodons. How is that possible?

• A) 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.
• B) Only about 40 of the recognized 61 codons are present in mRNA.
• C) There are tRNAs that can bind one of two related amino acids.
• D) Only 20 of the codons are active-one for each amino acid.

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Definitions:

Mean

A statistical measure that represents the average value of a set of numbers.

Median

The middle value in a data set when the values are arranged in ascending or descending order.

Mean

The arithmetic average of a set of numbers, calculated by dividing the sum of all values by the number of values.

Mode

An average of a group of values, computed by identifying the number that occurs most often.