U2L11

Question 1

What are the links between genotype and phenotype?

Answer 1

Proteins

Question 2

What is gene expression?

Answer 2

Process by which DNA directs protein synthesis

Question 3

What 2 stages are included in gene expression

Answer 3

Transcription and translation

Question 4

What is a primary transcript?

Answer 4

Initial RNA transcript from any gene prior to processing

Question 5

What is the central dogma?

Answer 5

Concept that cells are governed by cellular chain of command

Question 6

In eukaryotic cells, where does transcription and translation take place?

Answer 6

Transcription - nucleus
Translation - cytoplasm

Question 7

In bacterial cells, where does transcription and translation take place?

Answer 7

Cytoplasm

Question 8

What is a triplet code?

Answer 8

A series of non overlapping, three nucleotides where the flow of information from gene to protein is based on

Question 9

What happens to the triplet codes in mRNA?

Answer 9

Translated into a chain of amino acids forming a polypeptide

Question 10

Transcription creates…

Answer 10

An mRNA strand from the template strand

Question 11

Translation creates….

Answer 11

An amino acid sequences from the codons on mRNA

Question 12

Where does the RNA polymerase read the DNA template strand?

Answer 12

Reads it from 3’ to 5’ - next nucleotide will be added to the 3’ end

Question 13

What is the template strand used for?

Answer 13

Provides a template for ordering the sequence of complementary nucleotides in an RNA transcript

Question 14

During translation, codons are read in the

Answer 14

5’ -> 3’ direction

Question 15

What are codons used for?

Answer 15

Each codon specifies an amino acid placed at the corresponding position along the polypeptide

Question 16

How many codons in total

Answer 16

64

Question 17

The template strand is read

Answer 17

3’ to 5’

Question 18

What promoter is a polymerase II bounded to?

Answer 18

Transcription initiation complex

Question 19

Why is the TATA box crucial?

Answer 19

Forms the initiation complex in eukaryotes

Question 20

As RNA polymerase moves along the DNA, how many bases at a time does it untwist the double helix

Answer 20

10-20 bases

Question 21

How does the termination of transcription differ in bacteria and eukaryotes

Answer 21

In bacteria, the polymerase stops transcription at the end of terminator, in eukaryotes RNA polymerase II transcribes a polyadenylation signal sequence

Question 22

What is RNA processing

Answer 22

Enzymes in the nucleus of eukaryotes modify pre mRNA before it goes to the cytoplasm

Question 23

How are the ends of mRNA altered?

Answer 23

5’ end receives a modified nucleotide called the 5’ cap
The 3’ end gets a Poly A tail

Question 24

What are introns

Answer 24

Non coding regions

Question 25

What are exons

Answer 25

Regions that are expressed and translated into amino acid sequences

Question 26

What does RNA splicing do?

Answer 26

Removes introns and joins exons creating an mRNA molecule with continuous coding sequence

Question 27

Alternative RNA splicing

Answer 27

Some introns contain sequences that may regulate gene expression - treated as exons during splicing

Question 28

Number of different proteins an organism can produce is much greater than…..

Answer 28

It’s number of genes

Question 29

Domains

Answer 29

Are discrete regions in proteins

Question 30

Exon shuffling

Answer 30

Individual exons can code for different domains in a protein - exon shuffling may result in the evolution of new proteins