Pre-release Flashcards
In vivo
Studying the effects of things on living organism (animal models) rather than tissue extract
In vitro
Studying cells or biological molecules outside their usual biological context
Define tissue
Example: xylem tissue
Define organ
Example: lungs
Why are embryonic stem cells useful in research
- Can specialise into any tissue type
- Regenerate lost tissue
- Effects of disease can be studied on tissue without ethical implications of using a living organism
Where are totipotent stem cells found
Only present in first few cell divisions of an embryo. After this they become pluripotent
Evaluate ethics of using animal models
- Important research that could save human lives
- Simple nervous system so don’t experience pain like we do
- Annoy give consent and are subject to painful procedures
- Immoral to cause distress to any living organism
Define a gene
A sequence of nucleotide bases in DNA that codes for the sequence of amino acids in a polypeptide
Animal lines
Series of offspring in the same family that specifically carry a trait
Define ‘gene is expressed’
Made proteins from it
Very basically how do stem cells specialise
Different genes in DNA are activated and become expressed
5 step process of specialisation
- Cell contain same genes but not all are active/ expressed
- Under correct conditions some are activated/ inactivated
- mRNA only transcribes active genes, then translated into proteins
- Proteins modify cell structure and control cell processes
- Changes caused by proteins cause sell to specialise. Hard to reverse
How are genes activated/ inactivated
- Gene expression controlled by altering rate of transcription of genes
- Controlled by transcription factors
What are transcription factors
- Molecules or proteins that must be preset for mRNA to bind
- Bind to DNA at promoter region of a gene
- Activators help mRNA bind whereas represents prevent this
Where do the transcripts factors bind to?
Eukaryotes: DNA site called promoter region near start of target gene
Prokaryotes: operons
Define pluripotent
Ability to specialise into any cells except extra embryonic cells
What is premature exhaustion of cells
Early loss of cell function. Differentiated
Define tissue culture is
Growth of tissues or cells in an artificial medium, derived from living tissue but separate to the organism
Cell fate specification
Controlling what cell specialised into using gene switches
What are germ layers
- 3D structure that would develop into the cardiac muscle that forms the heart
How do viruses infect cells and reproduce
- Enters bloodstream through sex or damaged tissues
- Attaches to receptor molecule on host cell
- Inserts viral RNA/DNA into cell
- Reverse transcriptase to make DNA from RNA template
- DNA inserted into human DNA
- Makes viral proteins
How does a virus become an international medical emergency
Declared by world health organisation
What is microcephaly
Smaller brain and head size
What is the order of Harvard referencing
- Last name,
- First initial.
- (Year published).
- Title. (In italics)
- City: publisher, page(s)