1.3 Criteria

Question 1

What does gene expression involve?

Answer 1

Involves the transcription and translation of DNA sequences.

Question 2

Name 3 types of RNA:

Answer 2

Messenger RNA (mRNA), transfer RNA (tRNA), ribosomal RNA (rRNA).

Question 3

What does RNA nucleotides comprise of?

Answer 3

A ribose sugar, phosphate and one of four bases (C, G, A, U)

Question 4

What is the name of the base U, that replaces thymine?

Answer 4

Uracil

Question 5

What is the function on mRNA?

Answer 5

To carry a copy of the DNA code from the nucleus to a ribosome.

Question 6

Where is mRNA transcribed from DNA?

Answer 6

In the nucleus

Question 7

mRNA is translated into proteins by ribosomes where?

Answer 7

Cytoplasm

Question 8

Each triplet of bases on mRNA is called what?

Answer 8

Codon

Question 9

What does a codon code for?

Answer 9

specific amino acids

Question 10

Why is a tRNA molecule folded?

Answer 10

Due to complementary base pairing.

Question 11

What is the function of tRNA?

Answer 11

To carry a specific amino acid to a ribosome.

Question 12

A tRNA molecule has an anticodon. What is this?

Answer 12

An anticodon is a triplet of bases at one end and an attachment site for a specific amino acid at the other end.

Question 13

What does a ribosome comprise of?

Answer 13

rRNA and proteins

Question 14

What is transcription?

Answer 14

The production of a copy of the genetic code on DNA as mRNA can move out of the nucleus .

Question 15

As RNA polymerase moves along DNA, what does it do?

Answer 15

It unwinds the double helix and breaks the hydrogen bonds between the bases.

Question 16

What is the primary transcript of mRNA made from?

Answer 16

Is made from RNA nucleotides using complementary base pairing.

Question 17

How is the primary transcript used to produce the mature mRNA transcript?

Answer 17

It is spliced together

Question 18

Are introns coding or non-coding regions of the primary mRNA transcript?

Answer 18

non-coding regions which are removed

Question 19

Are exons coding or non-coding regions of the primary mRNA transcript?

Answer 19

Coding regions which are joined together to form the mature mRNA transcript

Question 20

In the mature mRNA transcript do exons remain in the same sequence?

Answer 20

Yes, they do not change order

Question 21

Where does the translation of mRNA into a polypeptide occur? And what else does it involve?

Answer 21

At the ribosome
Involves tRNA

Question 22

What does sequential translation of mRNA codons ensure?

Answer 22

Ensures the correct sequence of amino acids in a polypeptide chain

Question 23

What is the name of the codon at the start and end of a mature mRNA transcript?

Answer 23

Start and finish codons

Question 24

How does an anticodon bind to mRNA codons?

Answer 24

By complementary base pairing

Question 25

The genetic code is translated into a sequence of what?

Answer 25

Amino acids

Question 26

How are amino acids joined together?

Answer 26

By peptide bonds

Question 27

tRNA molecules leave the ribosome after doing what?

Answer 27

Delivering a specific amino acid

Question 28

Different proteins may be produced from one gene as a result of what?

Answer 28

Alternative RNA splicing

Question 29

Different mature RNA transcripts are produced from the same primary transcript depending on what?

Answer 29

Which exons are retained and which exons are removed

Question 30

Why do polypeptide chains have to be folded into a 3 dimensional shape?

Answer 30

To form a protein molecule

Question 31

Protein molecules are a result of what two interactions?

Answer 31

Hydrogen bonding and other interactions between individual amino acids

Question 32

Is there a small or large variety of protein molecule shapes?

Answer 32

Large variety

Question 33

What does the shape of a protein molecule determine?

Answer 33

The function of that protein

Question 34

How is the phenotype determined?

Answer 34

By proteins produced by gene expression

Question 35

What other factors can influence phenotype?

Answer 35

Environmental factors