Gene Regulation And Expression

Question 0

How are prokaryotic genes regulated

Answer 0

DNA binding protein regulate genes by controlling transcription

Question 1

How does differentiation occur?

Answer 1

Some genes are expresses and others are not

Question 2

What is an operon?

Answer 2

A group of genes that are regulated together

Question 3

How are lac genes turned off?

Answer 3

Lac depressor proteins being bound to a region called the operator

The repressor protein blocks RNA polymerase and transcription does not occur and turns genes off

Question 4

How are lac genes turned on

Answer 4

The presence of lactose which allows transcription to occur and the genes turn on

Question 5

How are eukaryotic genes more complex the prokaryotic

Answer 5

They have controlled individually and had regulatory sequences that are more complex

Have short region of DNA with 30 base pairs long

Question 6

What is a tata box

Answer 6

Marks the place where RNA polymerase to bind at a point just before transcription begins.

It’s the primary promoter in eukaryotes

Question 7

Why is a tata box necessary for transcription?

Answer 7

RNA polymerase cannot recognize the promotor on its own

Also helps position RNA polymerase to start transcription

Question 8

What decides which genes are turned on and which are turned off?

Answer 8

Transcription factors
Some serve as promotors
Some code for enhancer proteins that turn transcription on
Some code for repressor proteins that turn transcription off
Act as enhancer sequences

Question 9

What are Homeotic genes

Answer 9

Often called master control genes

Determines basic body plan (head, thorax, abdomen)

Question 10

What are homeobox genes?

Answer 10

Genes that control basic body structure

Determines factors like presence of wings or legs