Gene Expression

Question 1

Encoding protein

Answer 1

Structural genes

Question 2

Encoding products that interact with other sequences and affect the transcription and translation of these sequences

Answer 2

Regulatory genes

Question 3

DNA sequences that are not transcribes but play a role in regulating other nucleotide sequences

Answer 3

Regulatory elements

Question 4

Regulation of gene expression occur simultaneously in the cytoplasm

Answer 4

Prokaryotes

Question 5

Gene expression is regulated primarily at …..

Answer 5

Transcriptional level

Question 6

Gene regulation occurs at the epigenetic, transcriptional, post-transcriptional, translation and post-translational level

Answer 6

Eukaryotic

Question 7

Continuously expressed under normal cellular conditions

Answer 7

Constitutive expression

Question 8

Positive control

Answer 8

Stimulate gene expression

Question 9

Negative control

Answer 9

Inhibit gene expression

Question 10

Gene regulation is through…..

Answer 10

Chemical modification of chromatin/histone

Question 11

During transcription, gene regulation occurs through…

Answer 11

Transcription, RNA processing and translation

Question 12

Eukaryotic DNA is package as…

Answer 12

Chromatin

Question 13

Proteins that carry out transcription cannot access the DNA due to..

Answer 13

Chromatin being coiled

Question 14

Chromatin unravel to allow space for….

Answer 14

Transcriptional enzymes and proteins

Question 15

During chromatin remodelling, the nucleosomes are….

Answer 15

Repositioned to expose different stretches of DNA

Question 16

Remodelling can be due to chemical modification of ….

Answer 16

Histone tails

Question 17

Individual amino acids can be modified by the addition/removal of

Answer 17

Methyl and acetyl

Question 18

CpG is…

Answer 18

Addition of methyl group to cytosine in DNA

Question 19

CpG sites are often …. and near the …..

Answer 19

Clustered

Promoter region

Question 20

Methylation can …. over time or due to ….. response

Answer 20

Change

Environmental

Question 21

Heavy methylated CpG

Answer 21

Inhibits transcription

Question 22

Undermethylated CpG

Answer 22

Allows transcription

Question 23

Changes to the manner in which DNA is packaged, causing changes in gene expression

Answer 23

Epigenetic effects

Question 24

Th dosage of genes is twice as great in remains as it is in males

Answer 24

Genes on X chromosome

Question 25

Level of expression of X-linked genes is.... in both sexes

Answer 25

Equal

Question 26

Differential regulation is called...

Answer 26

Dosage compensation

Question 27

Inactivation of one X chromosome in each female cell

Answer 27

X-inactivation

Question 28

X-inactivation occurs at...

Answer 28

The time of implantation in the uterine wall

Question 29

The Xist non-coding RNA binds with the...

Answer 29

X-inactivation centre (XIC)

Question 30

Transcription of Xist contributes and the X-inactivation becomes coated with....

Answer 30

Xist RNA

Question 31

As transcription continues, the entire chromosome becomes coated with ...... and triggers ...... therefore ........

Answer 31

Xist RNA Methylation Transcription reduced

Question 32

Regulatory transcription factors bind at.... and the general transcription factors bind at ....

Answer 32

Enhancer sequences | Promoter region

Question 33

General transcription factors can recruit...

Answer 33

RNA Polymerase complex

Question 34

Transcription only takes place when all the regulatory transcription factors are...

Answer 34

Present and working together

Question 35

Some regulatory transcription factors bind to silencers and ....

Answer 35

Repress transcription factors

Question 36

Gene with multiple silencers and enhancers dependent on combination of regulatory transcription factors

Answer 36

Combinatorial control

Question 37

Adenosine——> | Deamination

Answer 37

Inosine

Question 38

Cytosine ——> | Deamination

Answer 38

Uracil

Question 39

Regulates by either binding to transcript and blocking translation, binding to transcript and causing degradation

Answer 39

Small Regulatory RNA

Question 40

RNAs fold back on itself to form a ...

Answer 40

Hairpin structure

Question 41

Enzymes recognise mRNA and cleave the stems of hairpin leaving ...

Answer 41

Small, double stranded fragments

Question 42

How many strands incorporated into protein complex (RISC)?

Answer 42

One

Question 43

What targets a region or mRNA?

Answer 43

RISC

Question 44

Does small regulatory RNA inhibit or allow translation?

Answer 44

Inhibit

Question 45

Degradation of RNA transcript caused by...

Answer 45

Target mRNA cleaved by RISC

Question 46

Post-translational modification is important because...

Answer 46

Some proteins are dangerous

Question 47

Translation machinery

Answer 47

5’ cap

Question 48

Proteins bind

Answer 48

5’ UTR

Question 49

Specific proteins bind

Answer 49

3’ UTR

Question 50

Translation inhibited post-translational level by?

Answer 50

Poly(A)

Question 51

Proteins are modified by the addition of one or more ...... to side chains of amino acids. A reversible addition of ..... to side chains Marking proteins for ..... by addition of chemical groups

Answer 51

Sugar molecules Phosphate groups Enzymatic destruction

Question 52

Activator protein binds to DNA for transcription to take place When activator protein is not present or able to bind to DNA, transcription does not occur

Answer 52

Positive regulation in prokaryotes

Question 53

A regulatory molecule binds DNA in order for transcription to be prevented RNA polymerase cannot be recruited so no transcription

Answer 53

Negative regulation

Question 54

Region of DNA that includes the coding sequence for multiple genes that get transcribed together into a single molecule of mRNA

Answer 54

Operon

Question 55

Gene for B-galactosidase | Lactose —-> glucose and galactose

Answer 55

Lac Z

Question 56

Gene for lactose permase | Transports lactose from external medium into cell

Answer 56

Lac Y

Question 57

During regulation of the lac operon is the ..... which encodes for .....

Answer 57

Lacl gene | Repressor protein

Question 58

Repressor binds with the operator, the RNA polymerase complex is not recruited and transcription does not take place

Answer 58

Absence of lactose

Question 59

Acts as an inducer because it prevents binding of repressor protein

Answer 59

Lactose

Question 60

Lactose causes ..... to be produced

Answer 60

Allolactose

Question 61

Lacl mutants do not produce functional repressor therefore....

Answer 61

Lac Z and Lac Y are expressed in presence and absence of lactose

Question 62

Two copies of operon are...

Answer 62

Wild | Mutation

Question 63

CRP-cAMP complex is a .... regulator of the lac operon

Answer 63

Positive

Question 64

CRP-cAMP is more sensitive to the ..... needs than ....

Answer 64

Nutritional | Lactose

Question 65

cAMP levels are high cAMP binds to CRP CRP to DNA Transcription activates

Answer 65

Absence of glucose

Question 66

Lactose operon is induced when ....

Answer 66

Lactose is present

Question 67

Lactose operon is not transcribed, even in present of cAMP-CRP

Answer 67

Lactose not present

Question 68

cAMP levels are low CAMP-CRP does not form CRP does not bind to lactose operon

Answer 68

Presence of glucose

Question 69

...... utilises glucose when both glucose and lactose are present

Answer 69

E.Coli

Question 70

Occurs in normal cells in good condition Virus uses cellular machinery of host to produce viral proteins Host cell bursts

Answer 70

Lytic pathway

Question 71

Takes place in cells in poor conditions Bacteriophage DNA undergo a process of recombination at specific sites Enlarged bacteriophage DNA in bacterial cell

Answer 71

Lysogenic pathway

Question 72

Predominance of cro protein

Answer 72

Lytic

Question 73

Predominance of cl protein

Answer 73

Lysogenic

Question 74

In prokaryotic cells, activators and repressor ..... and ..... transcription rates

Answer 74

Increase | Decrease

Question 75

Controls access to DNA sequences

Answer 75

Nucleosome spacing

Question 76

Access to DNA is controlled by

Answer 76

Histone modification

Question 77

RNA splicing removes ....

Answer 77

Introns

Question 78

Untranslated regions maintain

Answer 78

RNA stability

Question 79

Proteins can be recycled after being tagged with ....

Answer 79

Ubiquitin

Question 80

Described as a disease of altered gene expression

Answer 80

Cancer