8.1.1 Gene Mutations

• What are gene mutations?

  Permanent DNA sequence changes
• Order the main types of gene mutations:

  1️⃣ Substitution

  2️⃣ Insertion

  3️⃣ Deletion
• Nonsense mutations introduce a stop codon prematurely.
• Order the three possible effects of substitution mutations:

  1️⃣ Silent

  2️⃣ Missense

  3️⃣ Nonsense
• UV light is an example of a mutagen that can induce gene mutations.


  True
• There are three main types of gene mutations: substitution, insertion, and deletion.

  True
• What is the effect of a silent mutation on a protein?

  No effect
• What are examples of mutagens that cause induced mutations?

  Chemicals, radiation, viruses
• What type of mutation introduces a premature stop codon?

  Nonsense
• Gene mutations can only occur spontaneously.

  False
• What does a substitution mutation involve?

  Replacing one base pair
• Insertion and deletion mutations always cause a frameshift.


  True
• What are the two main categories of causes for gene mutations?

  Spontaneous and induced
• What effect does an insertion mutation have on a DNA sequence?

  Frameshift
• What happens in a substitution mutation?

  One base pair is replaced
• Match the mutation type with its description:

  Insertion ↔️ Adds one or more bases

  Deletion ↔️ Removes one or more bases
• Silent mutations do not change the amino acid coded, so there is no effect on the protein.

  True
• Insertion and deletion mutations cause a frameshift.
• Gene mutations can be induced by mutagens
• Silent mutations change the amino acid coded in a protein sequence.

  False
• What is the primary effect of a frameshift caused by insertion or deletion mutations?

  Alters protein structure
• Spontaneous mutations can arise due to DNA replication errors.
• Insertion and deletion mutations cause a frameshift that alters the protein sequence.
• A nonsense mutation introduces a premature stop codon.
• Order the two types of causes of gene mutations:

  1️⃣ Spontaneous mutations

  2️⃣ Induced mutations
• Nonsense mutations introduce a premature stop codon.
• Gene mutations can have consequences ranging from no effect to severe functional impairments.

  True
• What effect do missense mutations have on proteins?

  Change amino acid sequence
• Silent mutations do not change the amino acid coded.
• What are mutagens and what role do they play in gene mutations?

  Induced mutations
• Gene mutations can lead to silent, missense, or nonsense mutations.
• Insertion and deletion mutations cause a frameshift that dramatically alters the protein sequence.


  True
• Spontaneous mutations can arise from errors by DNA polymerase.
• What is the effect of a frameshift mutation on a protein?

  Changes the sequence
• What is the impact of a silent substitution mutation on a protein?

  No change