genetics exam 2

Question 1

promoters

Answer 1

help RNA polymerase start transcription

Question 2

enhancers

Answer 2

increase / speed up transcription process

Question 3

gene expression

Answer 3

creating a functional use for a gene, often for protein synthesis

Question 4

transcription

Answer 4

when RNA polymerase makes mRNA fron a DNA template strand

Question 5

transcription factors

Answer 5

regulatory factors that increase or decrease transcription

Question 6

repressors

Answer 6

bind to the operator sequence and blacks RNA polymerase from the transcription process

Question 7

introns

Answer 7

RNA potions that were removed after translation because they weren’t good enough

Question 8

extrons

Answer 8

the leftover parts excluding introns

Question 9

proks have gene regulation mechanisms that impact

Answer 9

transcription (ex. operon)

Question 10

operons

Answer 10

organized bacterial genes regulated by a single promoter
(this gets transcribed as a single mRNA)

Question 11

histone methylation

Answer 11

modification of specific amino acids in tail with
addition (or removal) of methyl group via histone methyltransferases

Question 12

histone acetylation

Answer 12

addition or removal of an acetyl group

Question 13

histone acetylation results in

Answer 13

increased rated of transcription

Question 14

often methylated histones

Answer 14

repress transcription

Question 15

Acetylation of lysines

Answer 15

neutralizes their positive charge

Question 16

DNA methylation of promoter region

Answer 16

represses transcription

Question 17

what is a methyl group

Answer 17

a small, stable molecule that consists of one carbon atom bonded to three hydrogen atoms (Me or CH3)

Question 18

Where is a methyl group
added/deleted

Answer 18

added to the lysine residues on the histone protein’s N-terminal tail

Question 19

What enzymes catalyze histone modifications

Answer 19

Histone methyltransferases,
Histone acetyltransferases

Question 20

enzymes catalyzing DNA modifications

Answer 20

DNMT1 in mammals, plays a crucial role in maintaining DNA methylation patterns during DNA replication

Question 21

Regulatory protein mutations: activators

Answer 21

loss of function mutation: reduce ability to enhance transcription, low levels of target gene expression

gain of function mutation: extreme high levels of target gene expression

Question 21

Regulatory protein mutations: repressors

Answer 21

loss of function: reduce the repressor’s capacity to inhibit transcription, leading to increased expression of target genes

gain of function: enhanced repression could result in lower levels of target gene expression than normal

Question 22

Point mutations

Answer 22

the substitution of a single nucleotide within a DNA sequence

Question 23

frameshift mutations

Answer 23

insertion or deletion of nucleotides, typically one or two nucleotides, that disrupt the reading frame of the coding sequence

Question 24

nonsense mutations

Answer 24

changes amino acid sequence to premature stop codon, often leads to nonfunctional proteins

Question 25

silent mutations

Answer 25

changes nucleotide to one coding for the same amino acid, leads to no trouble

Question 26

missense mutations

Answer 26

changes amino acid entirely which can reak havoc or give minimal damage