Genetics Flashcards
Meiosis
-homologous chromosomes pairs line up to form bivalents
-chiasma forms
-crossing over of chromosomes occurs to shuffle the alleles
-independent segregation seperation
-non-disjunction due to uneven separation of chromosomes/chromatids
-random mutations
-random fusion of haploid gametes
Transcription factor
Proteins involved in the process of transcribing DNA into RNA can stimulate or inhibit transcription
Move from cytoplasm to nucleus and bind to promoter region of DNA either enables or disables RNA polymerase from binding
Epigenetics
Process by which environment factors cause inheritable changes in gene functions without changing the bases in DNA
Oestrogen
-Is lipid soluble diffuses through PL
-binds to receptor molecule on transcription factor
-binding changes shape of DNA binding site on the transcription factor
-TF enters nucleus through nuclear pore and bind to promoter region of DNA
-RNA polymerase can now bind and transcription occurs gene is expressed
Methylation
Additional of methyl groups to molecules
Added to cytosine
Inhibits transcription Move
Histone complex
Tightly packed histone complex=
-no transcription
-no mRNA produced
-no translation
-no polypeptides produced
Tumour suppressor genes
Slow cell division by producing proteins that stop cells dividing
When mutation this become inactivated
Proto concogenes
Stimulates cells division by producing proteins that make the cell divide
Can make cell over activate
2 scientists who proposed models of DNA and replication
-James Watson
-Francis Crick
In vivo gene cloning
-cut gene out using restriction enzyme
-cut plasmid open using same enzyme
-join sticky end of gene and plasmid using DNA ligand
-add promoter region so gene can be processed
-transform plasmid into host cell using calcium ions and increase temp
-select colonic which have taken up gene using a marker gene
Monoclonal antibodies
antibodies produced
from a single group of genetically identical
Direct elisa
Direct ELISA (detect antigens)
(1) Antigen in
patient serum
sample fixed
in a well
(2) MA (attached to
enzyme, E) binds to antigen
(3) Substrate added to well
reacts with enzyme 🡪 coloured
product (positive result)
Removes unbound Ab
Prevents False +
WASH!
Indirect ELISA
(1) Antigen fixed in a well
(2) Primary antibody from
patient’s serum binds to antigen
(3) Secondary antibody (MA,
attached to enzyme, E) binds to
primary antibody’s constant region
WASH!
4) Substrate added to well reacts
with enzyme 🡪 coloured produce
(positive result)
WASH!
Describe the role of antibodies in producing a
positive result in an ELISA test (4)
- (First) antibody binds/attaches /complementary (in
shape) to antigen; - (Second) antibody with enzyme attached is added;
- (Second) antibody attaches to (first) antibody (indirect
ELISA test). - (Substrate/solution added) and colour changes;
Gene fingerprinting
-DNA cut using restriction endonuclease
-electrophoresis separates according to length/ mass or charge
-DNA made single stranded
-transfer to a nylon membrane and blot
-apply probe radioactive marker
-X-ray film exposure to identify labelled probes
Frameshift
Every triplet code altered after point of deletion so a completely different protein is made
Totipotent
Can divide to become any type of cell
Pluripotent
Can divide and become most types of cells
Multipotent
Can divide into limited type of cells
Unipotent
Can divide into one type of cell
Induced pluripotent
Derived from skin or blood cells that have been genetically altered using TF into embryonic like pluripotent
