Topic 3: Gene Expression

Question 1

Gene expression involves ________________________

Answer 1

the transcription and translation of DNA sequences

Question 2

Only a fraction of genes in a cell are ______

Answer 2

expressed

Question 3

Transcription and translation involve ____________

Answer 3

3 types of RNA (mRNA, tRNA, rRNA)

Question 4

RNA is ______

Answer 4

single stranded

Question 5

RNA is composed of nucleotides containing ____________

Answer 5

ribose sugar, phosphate, C, G, A, and Uracil bases

Question 6

mRNA carries a copy of the __________________

Answer 6

DNA code from the nucleus to the ribosome

Question 7

mRNA is transcribed from DNA ____________

Answer 7

in the nucleus

Question 8

mRNA is translated into proteins ____________

Answer 8

by the ribosomes in the cytoplasm

Question 9

Each triplet of bases on the mRNA is called ______

Answer 9

a codon

Question 10

A codon ______

Answer 10

codes for a specific amino acid

Question 11

How does tRNA fold?

Answer 11

due to complementary base pairing

Question 12

At one end of the tRNA molecule there is ____________

Answer 12

an anticodon (an exposed triplet of bases)

Question 13

Each tRNA carries a specific amino acid where?

Answer 13

to the ribosome

Question 14

What forms the ribosome?

Answer 14

rRNA and proteins

Question 15

What happens when RNA polymerase moves along the DNA?

Answer 15

unwinding of the double helix and breaking Hydrogen bonds

Question 16

What does RNA polymerase synthesise?

Answer 16

a primary transcript of mRNA from RNA nucleotides

Question 17

How are RNA nucleotides matched to the DNA template?

Answer 17

through complementary base pairing

Question 18

What is uracil complementary to?

Answer 18

Adenine

Question 19

Cytosine is complementary to?

Answer 19

Guanine

Question 20

How is a mature mRNA transcript formed?

Answer 20

RNA splicing

Question 21

what are introns of the primary transcript?

Answer 21

non-coding regions

Question 22

What are exons and what do they form?

Answer 22

coding regions and they are joined together to form the mature transcript

Question 23

what happens to the order of exons during splicing?

Answer 23

unchanged

Question 24

tRNA is involved in the translation of mRNA into __________

Answer 24

a polypeptide at a ribosome

Question 25

Translation starts with _____

Answer 25

a start codon

Question 26

translation ends with _____

Answer 26

a stop codon

Question 27

How do anticodons bond to codons?

Answer 27

By complementary base pairing

Question 28

What is the genetic code on the mRNA translated to?

Answer 28

A sequence of amino acids

Question 29

How are the amino acids joined together?

Answer 29

Through peptide bonds to form a polypeptide

Question 30

When is the polypeptide complete?

Answer 30

Wants to stop codon is read

Question 31

What happens to a tRNA after translation?

Answer 31

The tRNA leaves the ribosome and it’s free to pick up another amino acid

Question 32

How can different proteins be expressed from one gene?

Answer 32

As a result of alternative RNA splicing

Question 33

What can one primary transcript produce?

Answer 33

Several different mature mRNA transcripts

Question 34

What can alternative RNA spicing produce?

Answer 34

Different mature mRNA transcript depending on which exons are retained

Question 35

What does alternative splicing produce?

Answer 35

A variety of proteins from the same gene

Question 36

What are amino acids linked by?

Answer 36

Peptide bonds to form polypeptides

Question 37

What do polypeptide chains fold to form?

Answer 37

A 3-D shape of a protein

Question 38

How are the polypeptide chains held together?

Answer 38

By hydrogen bonds and other interactions between individual amino acids

Question 39

How is the phenotype determined?

Answer 39

By proteins produced as a result of gene expression

Question 40

What else can influence the phenotype?

Answer 40

Environmental factors