Transcription

Question 1

Name the process by which DNA is converted to RNA and where is this located?

Answer 1

Transcription in the nucleus

Question 2

Name the process by which RNA is converted to protein and where is this located?

Answer 2

Translation in the cytoplasm

Question 3

Name the 3 parts of transcription for both prokaryotes and eukaryotes

Answer 3

Initiation

Elongation

Termination

Question 4

What is made during transcription and what is made during translation?

Answer 4

Transcription - mRNA

Translation - protein

Question 5

The following RNA strand was produced:
5’ AAA AUG AGU AAG 3’

Give the DNA strand that could have been the template for this RNA

Answer 5

3’ TTT TAC TCA TTC 5’

Question 6

Match the following events with the correct stage:

Initiation

Elongation

Termination

a) RNA polymerase stops transcribing

b) RNA polymerase binds to the promoter

c) RNA polymerase adds complementary nucleotides to the 3’ of the RNA strand

Answer 6

a) Termination

b) Initiation

c) Elongation

Question 7

The following diagram represents the flow of genetic information from DNA to protein.

Step 1: DNA to pre-mRNA

Step 2: pre-mRNA to mRNA

Step 3: mRNA to Protein

Whta event is occurring during stage 2?

Answer 7

pre-mRNAs are modified to include only certain exons.

Question 8

Which of the following is true regarding the process of transcription?

DNA polymerases control transcription

Transcription uses both strands of DNA to make mRNA

The three stages of transcription are initiation, elimination and reduction

Transcription occurs for individual genes

Answer 8

Transcription occurs for individual genes

Question 9

Eukaryotic RNA polymerase II synthesizes which of the following?

a)RNA molecules that are precursors of rRNAs

b)RNA molecules that are precursors of mRNAs

c)RNA molecules that are precursors of tRNAs

d)RNA molecules that are precursors of snRNAs

Answer 9

B

Question 10

True or False

Polyadenylation at the 5’ end of mRNA is a type of pre-mRNA processing that protects the transcript from exonucleases.

Answer 10

True

Question 11

What are ‘Snurps’ made of?

Answer 11

RNA and Protein

Question 12

Give 4 Similarities between DNA replication and Transcription

Answer 12

Process involves initiation, elongation and termination

Synthesis is 5’ to 3’

Many proteins involved

Polymerases have several subunits

Question 13

Give some differences between Replication and Transcription

Answer 13

Replication:

DNA Polymerase

More accurate ( 1 mistake in every 10^9 nucleotides copied)

DNA molecules much longer

DNA remains bound to template strand

Both strand are copied

Transcription:

RNA Polymerase

Mistakes are frequent

RNAs are shorter

RNA is rapidly released

One strand is copied

Question 14

Name the 5 types of RNA ad give their function

Answer 14

mRNA - Messenger RNA code for proteins

rRNA - Ribosomal RNA, form the basic structure of the ribosome and catalyse protein synthesis

tRNA - Transfer RNAs, central to protein synthesis as the adaptors between mRNA and amino acids

Telomerase RNA - Serves as the template for the telomerase enzyme that extends the ends of chromosomes

snRNAs - Small nuclear RNAs, function in a variety of nuclear processes, including the splicing of pre-mRNA

Question 15

Name the 3 types of RNA polymerase and state the genes that they transcribe

Answer 15

RNA polymerase I - Pre rRNA (5.8S, 18S and 28S rRNAs)

RNA polymerase II - mRNA, snRNAs, siRNAs, miRNAs

RNA polymerase III - tRNAs, 5S rRNA , snRNA U6, 7S RNA and other stable short RNAs

Question 16

What processes need to happen before eukaryotic RNA molecules made in the nucleus can be translated in the ctyoplasm?

Answer 16

Capping

Splicing

Polyadenylation

Question 17

Name the protein-complex that is responsible for splicing

Answer 17

Snurps or snRNPs

Question 18

Name the stop and start codons

Answer 18

Start: UAA, UAG and UGA

Stop: AUG - methionine