AP Biology Unit 6.6-6.8 Review

Which mutation results in a change in the amino acid?

• Frameshift

• Nonsense

• Missense

• Silent

Answer explanation

A missense mutation is a substitution point mutation. One nucleotide is substituted with another. This substitution causes ONE amino acid to be substituted for ANOTHER amino acid.

This is similar to a word being substituted in a sentence.

I took my dog for a walk.

I took my fish for a walk.

Which mutation results in no change in the amino acid?

• Nonsense

• Missense

• Silent

• Frameshift

Answer explanation

A silent mutation is a substitution point mutation. One nucleotide is substituted with another. This substitution causes ONE amino acid to be substituted for the SAME amino acid.

Since you have the same amino acid, it is not obvious that there has been a mutation so it is SILENT.

Which mutation results from +/- one nucleotide base?

• Frameshift

• Missense

• Nonsense

• Silent

Answer explanation

If ONE nucleotide has been inserted or deleted, this will shift the reading frame. Recall, the reading frame is the group of triplets read as codons. If there is a shift by 1 or 2, the ribosome will be pairing the wrong codons. This will cause a change to all amino acids downstream from the insertion or deletion.

What is the primary source of genetic variation?

• Crossing over

• Alternative Splicing

• Mutations

• Random Fert

Answer explanation

Mutations will add NEW variation to the population. This will increase genetic variation.

Which of the following is the cause of Trisomy 21?

• Duplication

• Nondisjunction

• Frameshift mutation

• Point mutation

Answer explanation

Individuals with Trisomy 21 has an additional chromosome 21. This results from nondisjunction. Nondisjunction results from homologous chromosomes or sister chromatids not separating during anaphase I or II.

Cell-to-cell transmission?

• Conjugation

• Transformation

• Transduction

• Transposition

Answer explanation

Prokaryotes are able to undergo cell-to-cell transmission by passing genetic information through sex pili in a process called conjugation.

Viral transmission of traits

• Conjugation

• Transformation

• Transduction

• Transposition

Answer explanation

As seen during the Hershey and Chase experiment, bacteriophages traditionally will transduce their genetic information into the host nucleus.

Uptake naked DNA

• Conjugation

• Transformation

• Transduction

• Transposition

Answer explanation

During the transformation experiment, bacteria will take up genetic information (plasmids) from the environment to become antibiotic resistant bacteria/green glowing bacteria.

Mutation resulting in a different amino acid

• Frameshift

• Missense

• Nonsense

• Silent

Mutation resulting in the same amino acid

• Frameshift

• Missense

• Nonsense

• Silent