Lecture 19 - Mutations I

Question 1

Tinman gene mutation often causes what?

Answer 1

Heart defects

Question 2

Mutation of this gene were identified among 608 patients with congenital heart defects.

Answer 2

NKX2.5

Question 3

Describe somatic mutations

Answer 3

Arise in tissue other than germ-line and impact is restricted to the individual

Question 4

Describe germ-line mutations

Answer 4

Arise in tissues that produce gametes and can be passed on to offspring.

Question 5

Are gene mutations always harmful?

Answer 5

No

Question 6

What is a De novo mutation?

Answer 6

An alteration in a gene that is present for the first time in a family member. Due to a mutation in a germ cell of one of the parents or in the fertilized egg itself. can be either germ line or somatic

Question 7

What is a transition base substitution?

Answer 7

Substitution of a purine for a purine or a pyrimidine for a pyrimidine.

Question 8

What is a transversion base substitution?

Answer 8

Substitution of a purine for a pyrimidine or a pyrimidine for a purine.

Question 9

What are trinucleotide repeat mutations?

Answer 9

When extra trinucleotide sequences are added due to hairpin structures forming.

Question 10

What is a loss of function mutation?

Answer 10

Causes the complete or partial absence of a normal protein function. USUALLY RECESSIVE

Question 11

What is a neutral mutation?

Answer 11

Missense mutation that alters the amino acid sequence but does not change the function of the protein.

Question 12

What is a Silent mutation?

Answer 12

Mutation that a changes the codon sequence but not the amino acid sequence.

Question 13

What is a missense mutation?

Answer 13

Base substitution that results in a different amino acid

Question 14

What is a nonsense mutation?

Answer 14

Mutation that changes a sense codon into a termination codon.

Question 15

What is a forward mutation?

Answer 15

Mutation that alters the wild-type phenotype

Question 16

What is a Reverse mutation?

Answer 16

Mutation that changes the mutant phenotype back into the wild-type.

Question 17

What is a Gain of function mutation?

Answer 17

Produces an entirely new trait or causes it to appear in an inappropriate tissue or at an inappropriate time.

Question 18

What is a suppressor mutation?

Answer 18

Genetic change that hides or suppresses the effect of another mutation

Question 19

Intragenic suppressor mutations occur where?

Answer 19

Same gene

Question 20

Intergenic suppressor mutations occur where?

Answer 20

Different genes

Question 21

An individual that has both the original mutation and the suppressor mutation will display which phenotype?

Answer 21

Wild-type

Question 22

Insertion?

Answer 22

Addition of one or more nucleotides

Question 23

Deletion?

Answer 23

Deletion of one or more nucleotides

Question 24

Frameshift mutation?

Answer 24

Insertion or deletion that alters the reading frame of a gene.

Question 25

In-frame deletion or insertion?

Answer 25

Deletion or insertion of a multiple of three nucleotides that does not alter the reading frame

Question 26

Expanding nucleotide repeats?

Answer 26

Increases the number of copies of a set of nucleotides