Test 3

Question 1

__________: A test using strains of a bacterium, Salmonella typhimurium, to determine if a substance is a mutagen.

Answer 1

Ames test

Question 2

________________: A type of DNA repair in which a modified base is removed from a DNA strand. Following base removal, a short region of the DNA strand is removed, which is then resynthesized using the complementary strand as a template.

Answer 2

Base excision repair (BER)

Question 3

___________: When two bases opposite each other in a double helix do not conform to the AT/GC rule. For example, if A is opposite C, that would be a base mismatch.

Answer 3

Base mismatch:

Question 4

__________: A point mutation in which one base is substituted for another base.

Answer 4

Base substitution

Question 5

____________: The removal of an amino group from a molecule. For example, the removal of an amino group from cytosine produces uracil.

Answer 5

Deamination

Question 6

_______________: The removal of a purine base from DNA.

Answer 6

Depurination

Question 7

_________________: An enzyme recognizes an incorrect alteration in DNA structure and directly converts it back to a correct structure.

Answer 7

Direct repair

Question 8

____________: A mutation that involves the addition or deletion of nucleotides not in a multiple of three and thereby shifts thee reading frame of the codon sequence downstream from the mutation.

Answer 8

Frame shift mutations

Question 9

__________________: Occurs when the DNA strands from a sister chromatid are used to repair a lesion in the other sister chromatid.

Answer 9

Homologous recombination repair

Question 10

_________________: A mutation caused by environmental agents.

Answer 10

Induced mutation

Question 11

_______________________: A DNA repair system that detects a mismatch and specifically removes the segment from the newly made daughter strand.

Answer 11

Methyl-directed mismatch repair

Question 12

_______________________: A base substitution that leads to a change in the amino acid sequence of the encoded polypeptide.

Answer 12

Missense mutation

Question 13

__________: A permanent change in the genetic material that can be passed from cell to cell or from parent to offspring.

Answer 13

Mutation

Question 14

________________: The joining of the broken ends of chromosomes via nonhomologous end-joining proteins.

Answer 14

Nonhomologous end joining

Question 15

__________________: A mutation that involves a change from a sense codon to a stop codon.

Answer 15

Nonsense mutation

Question 16

_____________________: A DNA repair system in which several nucleotides in the damaged strand are removed from the DNA and the undamaged strand is used as a template to resynthesize a normal strand.

Answer 16

Nucleotide excision repair (NER)

Question 17

_____________________: Mutations are a random process – they can occur in any gene and do not involve exposure of an organism to a particular condition that selects for specific types of mutations.

Answer 17

Random mutation theory

Question 18

__________________: A technique in which a replica of bacterial colonies is transferred to a new petri plate.

Answer 18

Replica plating

Question 19

_________________: A mutation that does not alter the amino acid sequence of the encoded polypeptide even though the nucleotide sequence has changed.

Answer 19

Silent mutations

Question 20

____________________: A change in DNA structure that results from random abnormalities in biological processes.

Answer 20

Spontaneous mutations

Question 21

______________: A change in chemical structure such as an alternation between the keto and enol forms of the bases that are found in DNA.

Answer 21

Tautometic shift

Question 22

___________: A DNA lesion involving a covalent linkage between two adjacent thymine bases in a DNA strand.

Answer 22

Thymine dimers

Question 23

______________: A point mutation involving a change of a pyrimidine to another pyrimidine or a purine to another purine.

Answer 23

Transition

Question 24

____________: A point mutation in which a purine is interchanged with a pyrimidine or vice versa.

Answer 24

Transversion

Question 25

____________: A transcriptional regulatory protein that increases the rate of transcription.

Answer 25

Activator

Question 26

___________________: Refers to the phenomenon in which a pre-mRNA can be spliced in more than one way.

Answer 26

Alternative splicing

Question 27

_____________: A change in chromatin structure that alters the degree of compaction and/or the spacing (or both) of nucleosomes.

Answer 27

Chromatin Remodeling

Question 28

_______________: A group of CG sequences that may be clustered near a promoter region of a gene. The methylation of the cytosine bases usually inhibits transcription.

Answer 28

CpG island

Question 29

_____________: A DNA sequence that functions as a regulatory element. The binding of a regulatory transcription factor to the enhancer increases the level of transcription.

Answer 29

Enhancer

Question 30

_________________: The study of mechanisms that lead to changes in gene expression that can be passed from cell to cell and are reversible, but do not involve a change in the sequence of DNA.

Answer 30

Epigenetics

Question 31

_________________: An inheritance pattern in which a modification to a nuclear gene or chromosome alters gene expression in an organism, but the expression is not changed permanently over the course of many generations.

Answer 31

Epigenetics inheritance

Question 32

_______________________: One of several proteins that are necessary for basal transcription at the core promoter.

Answer 32

General transcription factor (GTS)

Question 33

___________________: small RNA molecules that can inhibit the expression of specific mRNAs via RNA interference.

Answer 33

MicroRNAs (miRNAs)

Question 34

__________________: A protein of protein complex that binds to a regulatory element and influences the rate of transcription via RNA polymerase.

Answer 34

Regulatory Transcription factor:

Question 35

_____________: A regulatory protein that binds to DNA and inhibits transcription.

Answer 35

Repressor

Question 36

__________________: Small RNA molecules that silence the expression of specific mRNAs via RNA inference.

Answer 36

SiRNAs

Question 37

___________________: A DNA sequence that functions as a regulatory element. The binding of a regulatory transcription factor to the silencer decreases the level of transcription.

Answer 37

Silencers