Unit 8 - The control of gene expression Flashcards
Types of mutations
Substitution
Deletion
Addition
Duplication
Inversion
Translocation
Why don’t all mutations affect the order of amino acids
Because Dna is degenerate
Why do additions, duplications and deletions have a higher chance of causing mutation?
They cause a frame shift which affects more codons
3 ways that mutagenic agents can cause mutation
Act as a base
Alter bases
Changing structure of DNA
Features of benign tumours
Non cancerous
Slow growing
Cannot form metastases
Features of malignant tumours
Grow rapidly
Form metastases
Travel using blood/ lymphatic system
Features of tumour cells
Irregular in shape
Larger nucleus
Don’t produce full proteome
Dont respond to growth- regulating processes
Divide more frequently than other cells
Features of tumour cells
Irregular in shape
Larger nucleus
Don’t produce full proteome
Dont respond to growth- regulating processes
Divide more frequently than other cells
Two types of factors that increase risk of cancer
Environmental factors
Genetic factors
Two types of factors that increase risk of cancer
Environmental factors
Genetic factors
What are stem cells
An unspecialised cell which can multiply indefinitely and can differentiate to become a specialised cell
4 types of stem cells
Totipotent
Pluripotent
Multipotent
Unipotent
What can stem cells be used to treat?
Spinal cord injuries
Heart disease and damage
Bladder conditions
Respiratory diseases
Organ transplants
3 sources of stem cells
Adult stem cells (Bone marrow)
Embryonic stem cells (Embryos 4-5 days old)
Induced pluripotent (Specialised cells which have been treated)
Ethical issues with embryonic stem cells
It is destruction of an embryo which could become a fetus
At the moment of fertilisation the induvidual has the right to life
Adult stem cells ar not as useful as embryonic stem cells
Some induced pluripotent stem cells may be rejected by the body
Steps for oestrogen promoting transcription of genes
- Oestrogen binds to a transcription factor forming an oestrogen- oestrogen receptor complex
- This activates the transcription factor
- This then binds to the promoter region of the gene
- This allows RNA polymarase to bind and transcription to occur