Gene Mutations and Transposable Elements

Question 1

A heritable change in the nucleotide sequence of DNA

Answer 1

Mutation

Question 2

How examining a mutant phenotype can reveal aspects of the normal function of the product of the wild-type allele

Answer 2

Genetic Analysis

Question 3

Relatively small alterations that affect a single gene or locus

Answer 3

Gene Mutations

Question 4

Large-scale alterations that affect chromosome number or chromosome structure

Answer 4

Chromosome Mutations

Question 5

Mutations that occur in somatic cells

Answer 5

Somatic Mutations

Question 6

Mutations that occur in gametes or gamete precursors and are transmitted to the next generation of offspring

Answer 6

Germ-Line Mutations

Question 7

The alteration of a single nucleotide

Answer 7

Base Substitution (Point Mutation)

Question 8

A mutation that alters the translation reading frame in coding regions

Answer 8

Frameshift Mutations

Question 9

A mutation that does not alter the translation reading frame in coding regions

Answer 9

In-frame Mutations

Question 10

A category of base substitution in which a pyrimidine is changes to a pyrimidine or a purine is changed to a purine

Answer 10

Transition

Question 11

A category of base substitution in which a purine is changed to a pyrimidine or a pyrimidine is changed to a purine

Answer 11

Transversion

Question 12

In many organisms, transitions are more common than transversions

Answer 12

Ts:Tv Bias

Question 13

When the amino acid produced by the codon is changed

Answer 13

Missense Mutation (Nonsynonymous Mutation)

Question 14

When a codon is changed to a stop codon

Answer 14

Nonsense Mutation

Question 15

When there is a mutation, but the amino acid does not change, occur at degenerate codons

Answer 15

Silent Mutation (Synonymous Mutation)

Question 16

A type of missense mutation in which the chemical properties of the mutant amino acid are similar to the original amino acid, in the same functional group. They often, but not always, have no effect on protein function

Answer 16

Conservative Mutation

Question 17

A type of missense mutation in which the chemical properties of the mutant amino acid are different from the original amino acid, in a different functional group. They often, but not always, have an effect on protein function

Answer 17

Nonconservative Mutation

Question 18

A type of dynamic mutation that involves three nucleotides. The number of copies of the repat often correlates with the severity and/or age of onset of the disorder

Answer 18

Expanding Nucleotide Repeats

Question 19

When a genetic disease becomes more severe with each generation, often shown in disorders caused by expanding nucleotide repeats

Answer 19

Anticipation

Question 20

Mutations that result in reduced or abolished activity of the gene product

Answer 20

Loss-of-Function Mutations

Question 21

A type of LOF mutation that completely blocks the function of a gene product

Answer 21

Null (Amorphic) Mutation

Question 22

A type of LOF mutation that results in weak, but detectable activity of gene product

Answer 22

Hypomorphic Mutation

Question 23

Mutations that enhance an activity or confer a new activity or location of an activity, usually have dominant inheritance

Answer 23

Gain-of-Function Mutations

Question 24

A type of GOF mutation that generates more gene product or the same amount of a more efficient gene product

Answer 24

Hypermorphic Mutation

Question 25

A type of GOF mutation that generates gene product with a new function or that is expressed at an inappropriate time or place

Answer 25

Neomorphic Mutation

Question 26

A mutation in which the wild-type allele is changed to a different allele

Answer 26

Forward Mutation

Question 27

A mutation in which the mutant allele changes back into the wild type

Answer 27

Reverse Mutation

Question 28

A general term for any genetic (DNA) unit that can reinsert elsewhere in the genome, generally 100-20000 bp long, occur in prokaryotes and eukaryotes

Answer 28

Transposable Elements

Question 29

A class of TE in which TEs move around a genome and increase their copy number

Answer 29

Replicative TEs (Class I, Retrotransposons)

Question 30

A class of TE is which TEs move around a genome but they don’t increase their copy number

Answer 30

Nonreplicative TEs (Class II, DNA Transposons)

Question 31

A type of Class II transposon with short inverted repeats at each end that requires transposase to move. It moves as DNA, and includes AC-DS elements (maize), Tn3 and Tn10, IS elements (E. coli), and P elements (Drosophila).

Answer 31

DNA Transposon

Question 32

A type of Class I transposon with long terminal repeats at each end, which requires reverse transcriptase and integrase to move. It moves via an RNA intermediate transcribes from a promoter in the LTR (replicative).

Answer 32

LTR Retrotransposon

Question 33

A type of Class I transposon with a PolyA at the 3’ end, and a 5’ end that is often truncated, which requires reverse transcriptase and endonuclease to move. It moves via an RNA intermediate that is often transcribes from a neighboring promoter (replicative). Includes LINEs and SINEs

Answer 33

Non-LTR retrotransposon

Question 34

A general type of class II TE in eukaryotes that carry a transposase gene and all DNA sequences needed to carry out transposition. Transposase encoded by one TE can act on another TE in the same genome. Includes Activator (Ac) elements of maize

Answer 34

Autonomous TEs

Question 35

A general type of class II TE in eukaryotes that lack a transposase gene and may lack the sequences needed to transposition. They are unable to move unless transposase is provided by an autonomous element elsewhere in the genome. Includes Dissociator (Ds) Elements of maize

Answer 35

Nonautonomous TEs

Question 36

Viruses that have genomes composed of single-stranded RNA, carry reverse transcriptase, and infect eukaryotic cells

Answer 36

Retroviruses