Gene Expression Flashcards
Give examples of mutagenic agents
High energy ionising radiation
Chemicals
What type of gene mutations are possible
Deletion Substitution Addition Duplication Inversion Translocation
Describe the gene mutation Duplication
One or more bases are repeated
Describe the gene mutation inversión
Base sequence is spliced and reinserted in reverse order
Describe the gene mutation translocation
Base sequence removed from. One chromosome and reinserted into another
Describe the posible outcomes of the gene mutation deletion
Frame shift resulting in non functional DNA
Describe the posible outcomes of the gene mutation substitution
No effect due to degenerate code or in intron
Formation of stop codon or different Amino acid
Describe the posible outcomes of the gene mutation addition
Frame shift resulting in non functional DNA
Describe the posible outcomes of the gene mutation Duplication
Frame shift right resulting in non functional DNA if sequence multiplied is not a multiple of 3
Frame shift to the right
Describe the posible outcomes of the gene mutation inversión
Change to one Amino acid
Or no chnage due to degenerate code
Describe the posible outcomes of the gene mutation translocation
Frame shift resulting in non functional DNA
When do gene mutations occur
During DNA replication
Why is differentiation and specialisation important in cells
No one cell can provide the optimum conditions for every function
How does a zygote divide
By mitosis
How can a zygote produce all the body cells in a human
All cells contain the same genes but some are switched on or off to allow for a particular function
What occurs during differentiation
Certain genes are switched off or on
Why is specialisation more efficient than not having specialised cells
Conserve energy and resources that might go to waste in mechanisms unnecessary for a particular function
Define a stem cell
A cell that retains the ability to become specialised
Why are xylem and red blood cells unable to differentiate
They are so specialised that they don’t have a nucleus and so don’t have the genes that can be turned off or on for specialisation
What general properties do stem cells possess
Able to divide and renew themselves over a long period of time
Unspecialised
Can differentiate into other specialised cells
What are the main sources of stem cells
Bone marrow
Embryo
Umbilical cord blood
Placenta
How are stem cells classified
By their ability tot differentiate
Define totipotent stem cells and give example sof where they are found
Can differentiate into any cell
Early embryo
Define pluripotent stem cells and give example sof where they are found
Can differentiate into almost any cell
embryonic and fetal stem cells
Define multipotent stem cells and give example sof where they are found
Can differentiate into a limited number of cells
Adult stem cells and Umbilical cord blood
Define unipotent stem cells and give example sof where they are found
Can differentiate into one type of cell
Adult tissue
Define the steps to forming a cardiomyocyte
Totipotent cell in Embryo
Pluripotent cell
Multipotent cell able to differentiate into any muscle cell
Unipotent cell only able to differentiate into cardiomyocyte
Cardiomyocyte
What do induced pluripotent cells derive from
Unipotent cells
How are induced pluripotent cells produced
Genes otherwise not expressed are expressed
Induce transcriptional factor synthesis
What do ips cells prove
That all cells contain same genes
How are ips cells different to embryonic stem cells
Able to self renew and unlimited number of times
What is the advantage of ips cells
They can replace embryonic stem cells in research
What disease can be cured using heart cells produced from stem cells
Heart damage
Eg from heart attack
What disease can be cured using skeletal muscle cells produced from stem cells
Muscular dystrophy
What disease can be cured using beta cells produced from stem cells
Type 1 diabetes
What disease can be cured using nerve cells produced from stem cells
Parkinsons Ms Strokes Alzheimers Paralysis
What disease can be cured using blood cells produced from stem cells
Leukemia
Inherited blood diseases