Gene expression

Question 1

3’ poly-A tail

Answer 1

A chain of adenine nucleotides added to the 3’ end of pre-mRNA during RNA processing. It makes the RNA molecule more stable and prevents its degradation.

Question 2

5’ methyl-G cap

Answer 2

A molecule added to the 5’ end of pre-mRNA during RNA processing. It makes the RNA molecule more stable and prevents its degradation. It also helps the ribosome attach to the mRNA.

Question 3

Activator protein

Answer 3

A protein coded for by a regulatory gene that increases gene expression.

Question 4

Alternative splicing (gene expression)

Answer 4

The functional group on amino acid molecules that is made up of one nitrogen and two hydrogens (NH2)

Question 5

Anticodon

Answer 5

Sequence of three nucleotides on a tRNA molecule that recognises a specific sequence of three nucleotides (codon) on an mRNA strand.

Question 6

antiparallel - DNA

Answer 6

A characteristic of DNA strands describing
how each strand runs in an opposite direction to the other. One strand runs in a 3’ → 5’ direction and the other runs in a 5’ → 3’ direction.

Question 7

Coding strand

Answer 7

The strand of DNA not transcribed by RNA polymerase, contains an identical sequence to the mRNA strand produced (except thymine is replaced with uracil in mRNA).

Question 8

Codon

Answer 8

The sequence of three nucleotides in mRNA coding for one amino acid.

Question 9

Degenerate

Answer 9

A property of the genetic code which means that a single amino acid can be coded for by more than one codon.

Question 10

Exons

Answer 10

Regions of DNA that code for proteins and are not spliced out during RNA processing

Question 11

Gene

Answer 11

A section of DNA that carries the code to make a specific protein or RNA product.

Question 12

Gene expression

Answer 12

The process of reading the information stored within a gene to create a functional product, typically a protein.

Question 13

Genetic code

Answer 13

The set of rules by which information is encoded in genetic material.

Question 14

Genome

Answer 14

The complete set of DNA housed within an organism.

Question 15

Introns

Answer 15

Non-coding regions of DNA that do not code for proteins. They are spliced out during RNA processing.

Question 16

Precursor messenger RNA (pre-mRNA

Answer 16

the immediate product of transcription of a DNA sequence. Requires modifications before it can undergo translation.

Question 17

Promoter

Answer 17

The sequence of DNA to which RNA polymerase binds.

Question 18

Reading frame

Answer 18

The order in which nucleotide triplets or codons are divided into a consecutive, non-overlapping sequence.

Question 19

RNA polymerase

Answer 19

the enzyme responsible for constructing a pre-mRNA sequence from a DNA sequence during transcription.

Question 20

Spliceosome

Answer 20

The enzyme that removes introns from the pre-mRNA molecule and joins exons together during RNA processing.

Question 21

Splicing

Answer 21

Process where introns are cut out of a pre-mRNA molecule, and exons are joined together.

Question 22

Start codon

Answer 22

The sequence of three nucleotides in mRNA that signals the start of translation.

Question 23

Stop codon

Answer 23

The sequence of three nucleotides in mRNA that signals the end of translation.

Question 24

TATA box

Answer 24

A type of promoter region.

Question 25

Template strand

Answer 25

The strand of DNA transcribed by RNA polymerase to produce a complementary pre-mRNA strand.

Question 26

Termination sequence - gene expression

Answer 26

A sequence of DNA that signals the end of transcription.

Question 27

Transcription

Answer 27

The process whereby a sequence of DNA is used as a template to produce a complementary sequence of mRNA.

Question 28

Transcription factor

Answer 28

Proteins that bind to the promoter region and control the functioning of RNA polymerase.

Question 29

Transfer RNA (tRNA)

Answer 29

RNA that recognises specific codons on the mRNA strand and adds the corresponding amino acid to the polypeptide chain during protein synthesis.

Question 30

Translation

Answer 30

The process where an mRNA sequence is read to produce a corresponding amino acid sequence to build a polypeptide.

Question 31

Triplet

Answer 31

The sequence of three nucleotides in DNA coding for one amino acid.