Regulation of Gene Expression

Question 1

Operator

Answer 1

What A cluster of functionally related genes can be coordinately
controlled by

segment of DNA

“On/Off Switch”

Question 2

Operon

Answer 2

the entire stretch of DNA that includes the
operator, the promoter, and the genes that they control

Question 3

Repressible Operon

Answer 3

one that is usually on

The trp operon is a repressible operon

Repressible enzymes usually function in anabolic pathways

Question 4

Inducible Operon

Answer 4

one that is usually off

The lac operon is an inducible operon

Inducible enzymes usually function in catabolic pathways

Question 5

Histone Acetylation

Answer 5

This appears to open up the chromatin structure, thereby promoting the initiation of transcription

Question 6

DNA Methylation

Answer 6

Addition of methyl groups to certain bases in DNA can condense chromatin and reduce transcription

Question 7

Enhancers

Answer 7

groupings of Distal control elements

Question 8

Activator

Answer 8

a protein that binds to an enhancer and stimulates transcription of a gene

Bound activators facilitate a sequence of protein−protein interactions that result in enhanced transcription of a given gene

Question 9

Oncogenes

Answer 9

Mutations in genes (called proto-oncogenes) that code for proteins that stimulate normal cell growth and division