manipulating genomes Flashcards
Describe PCR process in 7 steps
- DNA sample mixed with DNA nucloetides, primers, Mg2+, TAQ DNA polymerase
- mixture heated to 95°C to break H bonds, make 2 single strands of DNA. TAQ doesnt denature.
- cooled to 65°C so primers anneal to 3’ end of strand.
- TAQ binds to where double stranded DNA is.
- Temp raised to 72° for TAQ. Comp base pairing occurs
- when TAQ reaches end, new strand of double created
- process repeated, (heated back to 95°C)
whats a palindromic sequence (recognition sequences)
a sequence of DNA bases that consists of antiparallel base pairs
whats another way (other than PCR) to get a DNA fragment from an organism’s DNA
restriction enzymes
whats a restriction enzyme
enzymes that recognise specific recognition sequences and cut DNA at these places
whats gel electrophoresis
a technique that allows DNA fragments, RNA fragments or proteins to be separated on a gel according to size
outline the last 4 steps of gel electrophoresis after the gel has been set up
- pour in buffer till gel covered
- electrodes placed in ends of tank
- DNA samples loaded into wells, has overall negative charge
- smaller fragments travel further so can be compared
how does gel electrophoresis differ for RNA and proteins
- RNA fragments are same basic method as DNA
- proteins however can be positively charged so they’re mixed with chemicals that denatures them so they all have the same charge.
whats a DNA profile
a DNA gel that shows the number of times repetitive, non-coding base sequences are repeated at different loci in an individual. (Banding pattern)
Name 3 applications of DNA profiling
- forensic science
- maternity and paternity disputes
- analysis of disease
Whats STR sequences of DNA
short tandem repeat sequences, highly variable short repeating lengths of DNA
whats a transformed organism
a organism that has had its genes altered by genetic engineering
whats recombinant DNA
the name for DNA formed by joining together DNA from different sources
whats a transgenic organism
an organism that has been genetically engineered to include a gene from a different species
whats a vector (in gene terminology)
something used to transfer DNA into a cell
whats electroporation
a technique that uses an electric field to increase the permeability of cell membranes, which allows the cells to take up biological material
Name the 3 parts of the process of genetic engineering
1) obtaining DNA containing the desired gene (via restriction enzymes)
2) Making recombinant DNA (vector + DNA fragment, CBP, DNA ligase)
3) transforming cells (transferring gene gene into host cell)
Name 2 + and 2 - ethical issue with GMO crops
+reduce amount of pesticides used on crops which are harmful to environment
+designed to be more nutritious/ higher yield
-May encourage monoculture, reduce biodiversity, leave crops vulnerable to disease
-risk of interbreeding of plants creating superweeds
whats pharming
producing pharmaceutical using genetically modified organisms, e.g. animals
Name 1 + and 1 - ethical issue with pharming
+can be made in large quantities compared to other methods making them more available
-potential harmful side effects of manipulating genes for animals
Name 1 + and 3 - ethical issue with genetic modification of pathogens
+previously untreatable diseases can now be treated, reducing suffering they would cause
- scientists researching could be infected, cause mass outbreak
- GM version of pathogen could revert back to original form cause outbreak
- could be used for biowarfare
whats somatic gene therapy
a possible treatment option for genetic disorders and some cancers that involves altering defective genes inside body cells
whats germ line theory
a possible cure for genetic disorders and some cancers that involves altering defective genes inside sex cells
Name 3 + and 3 - ethical issue with gene therapy
+prolong lives of people with life threatening disease
+give people with genetic disease better quality of life
+germ line therapy would allow carrier of disorder to conceive healthy babies
-technology could be misused e.g. cosmetic factors
-potential to harm patient (over expression of genes)
-expensive, money potentially better spent somewhere else
name 4 disadvantages of gene therapy
- body may identify vectors as foreign, start immune response
- allele could be inserted to wrong place in DNA
- inserted allele could be over expressed
- effects may be short lived in somatic therapy
