Mutations

Question 1

What are mutations?

Answer 1

Random changes in the genome that can result in either no protein or an altered protein being synthesized

Mutations can range from a change in a single base to changes in chromosome structure or number.

Question 2

If a mutation results in an alteration to the organism’s phenotype, it is called a _______.

Answer 2

mutant organism

Mutations can cause alterations to the genome which may contribute to the evolution of a species.

Question 3

Mutations are spontaneous and can occur during what two processes?

Answer 3

• DNA replication
• Gamete formation

These processes can lead to alterations in the genome.

Question 4

What is a single gene mutation?

Answer 4

A mutation resulting from a single nucleotide base change

The DNA nucleotide sequence is altered by substitution, insertion, or deletion of nucleotides.

Question 5

What are the three types of single nucleotide substitutions?

Answer 5

• Missense
• Nonsense
• Splice-site

These substitutions can lead to minor or major changes in the protein synthesized.

Question 6

What is the impact of a substitution mutation on the DNA base sequence?

Answer 6

Changes one codon, resulting in a minor change to the protein produced

The specific impact depends on the nature of the substitution.

Question 7

What is the impact of an insertion mutation on the DNA base sequence?

Answer 7

Major change to protein structure

Insertion mutations can significantly alter the resulting protein.

Question 8

What is the impact of a deletion mutation on the DNA base sequence?

Answer 8

Major change to protein structure

Deletion mutations can also lead to significant alterations in the protein.

Question 9

When describing the effect of a mutation on a gene, you should mention the _______.

Answer 9

nucleotide base sequence or codons

This is crucial for understanding the specific changes caused by mutations.

Question 10

When describing the effect of a mutation on the structure of a protein, you should mention the _______.

Answer 10

amino acid sequence

This highlights how mutations can affect protein function.

Question 11

What is a mutation?

Answer 11

A change in the nucleotide sequence of DNA

Mutations can affect the phenotype of an organism.

Question 12

Define substitution mutation.

Answer 12

Change of one codon to another

This can lead to missense or nonsense mutations.

Question 13

What is a missense mutation?

Answer 13

A mutation that results in a different amino acid being translated

This can potentially change the protein shape.

Question 14

What is a nonsense mutation?

Answer 14

A mutation that changes a codon to a stop codon

This can lead to a shortened, non-functional protein.

Question 15

What does a splice-site mutation affect?

Answer 15

Change in nucleotide at a splice-site

This can prevent proper splicing, leading to different proteins being synthesized.

Question 16

What is the effect of a deletion mutation?

Answer 16

Shortens the protein

This may result in a non-functional protein or change its function.

Question 17

What is the effect of an insertion mutation?

Answer 17

Causes a frame-shift change

This can lead to a very different protein being synthesized.

Question 18

What is the potential outcome of a mutation on a protein?

Answer 18

• Different amino acid translated
• Possible change in protein shape
• May produce a non-functional protein
• May have little effect on the protein

The impact of mutations can vary widely.

Question 19

What are nucleotide insertions or deletions known to result in?

Answer 19

frame-shift mutations

These mutations can lead to changes in the amino acid sequence, potentially resulting in faulty or non-functional proteins.

Question 20

What happens to the subsequent codons when a frame-shift mutation occurs?

Answer 20

All subsequent codons and thus amino acids are changed

This alteration can have significant effects on protein function.

Question 21

Mutations in some non-coding DNA sequences can result in changes to what?

Answer 21

The way certain genes are expressed

This can affect gene regulation and expression levels.

Question 22

List the types of chromosome structure mutations.

Answer 22

• Duplication
• Deletion
• Inversion
• Translocation

These mutations affect whole chromosomes or sections of the genome.

Question 23

True or false: Frame-shift mutations can lead to conditions like sickle-cell disease and cystic fibrosis.

Answer 23

TRUE

These conditions are examples of diseases caused by specific types of mutations.

Question 24

What is the mutation that occurs when extra copies of genes on a homologous chromosome are generated?

Answer 24

duplication

Duplications can lead to significant changes in the genome.

Question 25

What is the **mutation** that results when a section of chromosome is removed?

Answer 25

deletion ## Footnote Deletions can cause large alterations in the genome and may affect many genes.

Question 26

What is the **mutation** called when a section of a chromosome is reversed?

Answer 26

inversion ## Footnote Inversions can disrupt gene function and lead to defective proteins.

Question 27

What is the **mutation** that occurs when a piece of chromosome detaches from one chromosome and moves to a new position on a non-homologous chromosome?

Answer 27

translocation ## Footnote Translocations can lead to significant genomic alterations and affect gene expression.

Question 28

True or false: **Chromosome mutations** often involve large segments and can make them lethal.

Answer 28

TRUE ## Footnote Substantial changes in chromosome mutations can result in lethal outcomes due to defective proteins.