1. They are in equal amounts.
The table below shows the number of individual molecules obtained when a DNA molecule from a bacterial species is broken down.
What data in the table indicates that adenine pairs with thymine in a DNA molecule?
They are in equal amounts.

4. DNA base sequence: T A C T T A T C A T A G
Complete the chart below to show the mRNA codons and amino acids coded for by the
DNA base sequence.
DNA base sequence: T A C T T A T C A T A G
mRNA codons _____ _____ _____ _____
Amino acids _____ _____ _____ _____

5. AUG|AAU|AGU|AUC DNA base sequence: T A C T T A T C A T A G
Complete the chart below to show the mRNA codons and amino acids coded for by the
DNA base sequence.
DNA base sequence: T A C T T A T C A T A G
mRNA codons _____ _____ _____ _____
Amino acids _____ _____ _____ _____
AUG|AAU|AGU|AUC

6. AUG|AAU|AGU|AUC MET|ASN |SER | ILE
Complete the chart below to show the mRNA codons and amino acids coded for by the
DNA base sequence.
DNA base sequence: T A C T T A T C A T A G
mRNA codons _____ _____ _____ _____
Amino acids _____ _____ _____ _____
AUG|AAU|AGU|AUC
MET|ASN |SER | ILE

7. Notice how the codon AAU codes for ASN.
What would happen if a DNA mutation changed the RNA codon to AAC?
Mutations that DO NOT change amino acid sequences are called SILENT MUTATIONS.
Nothing changes, because AAC also codes for ASN.

8. What if a code change DOES change the amino acid sequence?
DNA holds the code
The code determines the amino acid sequence.
The sequence determines the protein’s shape.
The shape determines the function.
What if a code change DOES change the amino acid sequence?

9. DNA mutation Change of RNA Different amino acids Altered protein or enzyme

10. Mutations that change enzymes or proteins are usually bad and often lethal tay sachs vid@ 15 min

11. Which mutation in a fruit fly could be passed on to its offspring?
(1) a mutation in a cell of an eye that changes the
color of the eye
(2) a mutation in a leg cell that causes the leg to be
shorter
(3) a mutation in a sperm cell that changes the
shape of the wing
(4) a mutation in a cell of the digestive tract that
produces a different enzyme