Ch 14-2

Question 1

What is the role of RNA polymerase in transcription?

Answer 1

RNA polymerase synthesizes RNA from a DNA template

Question 2

What are the key components of transcription?

Answer 2

RNA polymerase
●
Promoter (start site)
●
Terminator (stop signal)

Question 3

Define upstream and downstream in the context of nucleotide sequences.

Answer 3

Upstream: A sequence located before another sequence
●
Downstream: A sequence located after another sequence

Question 4

What are the three stages of transcription?

Answer 4

Initiation
●
Elongation
●
Termination

Question 5

Describe the initiation stage of transcription.

Answer 5

DNA unwinds, and RNA polymerase binds to the promoter region.

Question 6

How does the initiation of transcription differ in bacteria and eukaryotes?

Answer 6

Bacteria: RNA polymerase directly recognizes and binds to promoter sequences.
●
Eukaryotes: Requires transcription factors to mediate RNA polymerase II binding and initiation.

Question 7

What is the TATA box, and where is it located?

Answer 7

A sequence about 25 nucleotides upstream of the start site in most eukaryotic promoters

Question 8

What is the purpose of end modifications to pre-mRNA in eukaryotes?

Answer 8

Facilitate export from the nucleus
●
Protect mRNA from degradation
●
Aid in ribosome attachment

Question 9

Define introns and exons.

Answer 9

Introns: Non-coding regions within eukaryotic genes.
●
Exons: Coding segments that are spliced together.

Question 10

What are ribozymes?

Answer 10

RNA molecules that act as enzymes.

Question 11

Which process transfers information from DNA to mRNA?

a) Translation

b) Transcription

c) Replication

d) Termination

Answer 11

B

Question 12

What is the start codon?

a) UAA

b) UGA

c) UAG

d) AUG

Answer 12

D

Question 13

What signals the end of transcription?
○
a) Start codon
○
b) Promoter
○
c) Terminator
○
d) Transcription factor

Answer 13

C

Question 14

In which direction is RNA synthesized during elongation?
○
a) 3’ to 5’
○
b) 5’ to 3’
○
c) N-terminus to C-terminus
○
d) C-terminus to N-terminus

Answer 14

B

Question 15

What is the function of the promoter in transcription?
○
a) Region of attachment for RNA polymerase
○
b) Signal to stop transcription
○
c) Site of mRNA degradation
○
d) Initiates translation

Answer 15

A

Question 16

What role do transcription factors play in eukaryotic transcription?

a) Directly synthesize RNA

b) Remove introns from pre-mRNA

c) Mediate RNA polymerase II binding

d) Transport mRNA out of the nucleus

Answer 16

C

Question 17

What sequence is often found about 25 nucleotides upstream of the start site in eukaryotic promoters?

a) Poly-A tail

b) 5’ cap

c) TATA box

d) Terminator sequence

Answer 17

C

Question 18

What is the function of the poly-A tail in eukaryotic mRNA?
○
a) Initiates translation
○
b) Protects mRNA from degradation
○
c) Binds to the promoter region
○
d) Serves as a template for protein synthesis

Answer 18

B

Question 19

What is the process of removing introns from pre-mRNA called?
○
a) Transcription
○
b) Translation
○
c) Splicing
○
d) Replication

Answer 19

C

Question 20

What characteristic of RNA molecules allows them to function as enzymes (ribozymes)? *
a) Linear structure *
b) Inability to form hydrogen bonds *
c) Ability to base pair and form a 3-dimensional shape *
d) Presence of deoxyribose sugar

Answer 20

C

Question 21

The process of synthesizing RNA from a DNA template is called

Answer 21

Transcription

Question 22

What is the start codon that codes for methionine.

Answer 22

AUG

Question 23

The three stop codons are

Answer 23

1) UAA
2) UGA
3) UAG

Question 24

The __ is a region on DNA where RNA polymerase binds to initiate transcription.

Answer 24

Promoter

Question 25

The sequence that signals the end of transcription is called the __

Answer 25

Terminator

Question 26

In eukaryotes, the __ is a crucial promoter element located upstream of the transcription start site.

Answer 26

TATA box

Question 27

__ factors are proteins that help regulate transcription by binding to DNA

Answer 27

Transcription

Question 28

The __ and __ tail are modifications added to eukaryotic mRNA.

Answer 28

5’ cap and poly A

Question 29

__ are noncoding sequences that are removed from pre-mRNA.

Answer 29

Introns

Question 30

__ are RNA molecules with catalytic activity.

Answer 30

Ribozymes

Question 31

T/f Transcription occurs in the cytoplasm of eukaryotic cells.

Answer 31

F Transcription occurs in the nucleus of eukaryotic cells.

Question 32

T/f RNA polymerase is responsible for adding nucleotides to the growing RNA chain during transcription.

Answer 32

T

Question 33

T/f The promoter region is located downstream of the coding sequence.

Answer 33

F The promoter region is located upstream of the coding sequence.

Question 34

T/f In bacteria, RNA polymerase can directly bind to the promoter region without the need for transcription factors.

Answer 34

True

Question 35

T/f The TATA box is a sequence commonly found in prokaryotic promoters.

Answer 35

F The TATA box is a sequence commonly found in eukaryotic promoters.

Question 36

T/f The addition of a 5' cap and a poly-A tail helps to stabilize mRNA and protect it from degradation.

Answer 36

T

Question 37

T/f Exons are non-coding sequences that are removed during RNA splicing.

Answer 37

False Exons are coding sequences that are retained during RNA splicing.

Question 38

T/f Alternative RNA splicing can result in the production of different protein isoforms from a single gene.

Answer 38

T

Question 39

T/f Ribozymes are proteins with enzymatic activity.

Answer 39

F Ribozymes are RNA molecules with enzymatic activity

Question 40

T/f The genetic code is universal, meaning the same codons code for the same amino acids in all organisms.

Answer 40

T