Mutations

A DNA mutation results in a protein that is the same as the initial protein synthesized before the mutation. Which statement BEST explains this outcome?

• One amino acid substitution does not affect protein synthesis.

• Different codons can be translated into the same amino acid, so some mutations do not affect protein synthesis.

• Only mutations that occur at the chromosomal level change protein function.

• Amino acids have similar functions, so their corresponding proteins are unaffected by mutations.

Answer explanation

The correct choice explains that different codons can code for the same amino acid, meaning some mutations are silent and do not change the protein's structure or function, resulting in the same protein being synthesized.

Tags

NGSS.HS-LS1-1

Which mutation would have the MOST significant impact on the gene product? Review the diagram carefully.

• Mutation 1

• Mutation 2

Answer explanation

Mutation 2 likely causes a significant change in the amino acid sequence, potentially altering the protein's structure and function. In contrast, Mutation 1 may have a lesser effect, making Mutation 2 the most impactful.

Tags

NGSS.HS-LS3-2

Why would the impact of the mutation you chose be so significant?

• Because a single nucleotide change never affects protein function.

• Because only silent mutations occur that do not affect the protein.

• Because the mutations result in a frameshift, altering the amino acid sequence significantly.

• Because codon charts cannot predict changes in protein structure.

Answer explanation

The correct choice highlights that a frameshift mutation alters the reading frame of the genetic code, leading to a completely different amino acid sequence, which can significantly impact protein function.

Tags

NGSS.HS-LS3-2

NGSS.HS-LS1-1

Which of these shows an example of an insertion mutation? Select ONE correct answer.

Tags

NGSS.HS-LS3-2

Which statements explain how a mutation in a somatic cell is different from a mutation that occurs in gametes?

• Somatic cell mutations occur in cells that give rise to gametes. Gamete mutations occur in cells that result in apoptosis.

• Somatic cell mutations are maintained in the gene pool. Gamete mutations are expelled from the gene pool.

• Somatic cell mutations are generally not passed to offspring. Gamete mutations are usually passed to offspring.

• Somatic cell mutations will not be expressed by the individual that contains the mutation. Gamete mutations will be expressed by the individual.

Answer explanation

Somatic cell mutations occur in non-reproductive cells and are not inherited, while gamete mutations occur in reproductive cells and can be passed to offspring, affecting future generations.

Tags

NGSS.HS-LS3-2

An illustration of how a particular DNA mutation will most likely affect the polypeptide produced is shown. What type of mutation is illustrated?

• Insertion

• Translocation

• Substitution

• Deletion

Answer explanation

The mutation illustrated is a substitution, where one nucleotide is replaced by another. This can lead to a change in a single amino acid in the polypeptide, affecting its function.

Tags

NGSS.HS-LS3-2

NGSS.HS-LS1-1

When a new mutation occurs in a somatic cell of a sexually reproducing organism, what percentage of the individual's offspring are likely to inherit the mutation?

• 100%

• 75%

• 25%

• 0%

Answer explanation

Somatic mutations occur in non-reproductive cells and are not passed to offspring. Therefore, the percentage of an individual's offspring likely to inherit the mutation is 0%.

The model shows a mutation to a partial sequence of bases in a gene. Which type of mutation does the model demonstrate?

• Deletion

• Insertion

• Substitution

• Translocation

Answer explanation

The model demonstrates an insertion mutation, which involves adding one or more nucleotide bases into a gene sequence. This type of mutation alters the genetic code by introducing new bases, unlike deletions or substitutions.

Tags

NGSS.HS-LS3-2

Exposure to the building material asbestos has been linked to certain types of cancers. Asbestos causes mutations in the p53 gene, which controls tumor suppression. Which statement best explains why people with cancer due to asbestos exposure do not pass the mutation on to their offspring?

• The mutation occurred in gametic cells.

• The mutation occurred in somatic cells.

• The mutation is recessive.

• The mutation is sex-linked.

Answer explanation

The mutation caused by asbestos exposure occurs in somatic cells, which are not involved in reproduction. Therefore, these mutations cannot be passed on to offspring, as only mutations in gametic cells can be inherited.