Chapter 18

Question 1

on by default; binding of repressor shuts off transcription

Answer 1

Repressible operon

Question 2

off by default; binding of repressor turns on transcription

Answer 2

Inducible operon

Question 3

How does the lac operon work?

Answer 3

When the lac operon binds onto the repressor, this allows transcription of enzymes to happen

Question 4

How does the trp operon work?

Answer 4

When the repressor binds to the operator, it prevents enzyme production by blocking RNA polymerase from doing transcription

Question 5

Sequence of nucleotides near the start of an operon to which an active repressor can attach

Answer 5

Operator

Question 6

Protein that inhibits transcription

Answer 6

Repressor

Question 7

Any substance that slows down or stops an enzyme catalysed reaction

Answer 7

Inhibitor

Question 8

Consists of a promoter, operator, cluster of genes

Answer 8

Operon

Question 9

A gene that is involved in the production of a substance that controls or regulates the expression of one or more genes

Answer 9

Regulatory Gene

Question 10

a point mutation in which a single nucleotide change results in a codon that codes for a different amino acid

Answer 10

Missense mutation

Question 11

is a point mutation in a sequence of DNA that results in a premature stop codon, or a nonsense codon in the transcribed mRNA, and in a truncated, incomplete, and usually nonfunctional protein product.

Answer 11

Nonsense mutation

Question 12

Why do nosense mutation cause a total lack of pain sensation?

Answer 12

A stop codon is produced, the protein product would be non-functional

Question 13

Why do missense mutations cause multiple pain disorders?

Answer 13

They can code for different amino acids, causing pain sensations to vary