8.2.3 Gene Expression

Question 1

How can tumors/ cancer form

Answer 1

Mutation in DNA genes controlling mitosis

Uncontrolled cell division

Tumour formed if this resulted in a mass of abnormal cells
-malignant, cancerous and spread via metastasis
-benign non cancerous

Question 2

Characteristics between begin and malignant

Answer 2

Begin:
-grow slowly
-regular nuclei
-well defined boarders
-can be removed by surgery and rarely return

Malignant:
-grow faster
-irregular nuclei
-poorly defined boarders
-can be removed with surgery but often return Malignant

Question 3

Function of tumor suppressor gene

Answer 3

Codes for a protein:
that inhibits/slows cell cycle

Or

Causes self-destruction of potential tumors

Question 4

What would happen with no tumor suppressor gene

Answer 4

Mutation in DNA produces non-functional protein:
-leads to a change in amino acid sequence

Decreasing histone acetylation or increasing methylation to prevent production of protein (RNA polymerase dosent bin To promoter region, no transcription)

Both lead to uncontrolled cell didvisoon

Question 5

Function of proto-oncogenes

Answer 5

Code for Proteins that stimulate cell division

Question 6

Role of oncogenes in development of tumours

Answer 6

Mutation in DNA-overproduction of protein

Decreased meth or increased histone acetylation, increased transcription

Leads to uncontrolled cell division

Question 7

Relevance of epigenetic in cancer treatment

Answer 7

Can turn on/off meth and acetylation

Increase in Mehta inhibits

Question 8

Role of oestrogen in developing breast cancer

Answer 8

Breast cancer cells have oestrogen receptors (inactive transcription factors)

If oestrogen increases more of it binds so activates transcription factors

They bind to promoter region of genes, stimulation cell division

Increase transcription/expression of genes