These are full comprehensive notes on the entire Module of Gene technologies for the AQA A-level specification. They are written using a mixture of my own research, class learning and the specification. They include diagrams, step by steps and everything I needed to get an A* in A-level Biology.
A genome works by collecting DNA samples from many individuals of species These DNA samples then sequenced
project a . are
and compared to cre ate a reference genome .
More than one individual i s used a s on e organism may have anomalies or
mutations that a re
atypical for the species .
A reference genome represents an average genome for a species based on a
genome project comparing the genome of many
individuals of the same species .
9 Shorter
>
easy to determine
genome of simpler
proteome (prokaryotes)
organisms
a l l DNA is part of a
gene r
snot associated with histones
coding for a protein
no non -
coking regions Corley exons )
The Human Genome
International research program which aimed to complete mapping and understanding of all the
genes of human beings .
Began in 1990 and completed in 2003 .
3 billion base pairs long ,
so 25000
genes .
Bsenefits : cures for genetic diseases , cheaper and beneficial medicine , genes linked to breast cancer and Alzheimers .
Recombinant DNA and Isolating Genes .
Genetic code is universal .
So scientists a re able to
artificially change an organism's DNA by combining lengths of nucleotides
from different sources .
Altered DNA i s called recombinant DNA .
If an organism contains nucleotide sequences from a different species it is called a transgenic organism Any organism that.
has introduced genetic material is a
genetically modified organism (GMO] Transcription and
. translation a re also universal .
Three main ways to obtain desired gene
:
① gene can be identified using a
gene probe and then c u t from the DNA fragment using an
enzyme called a restriction enzyme .
② a
copy of the gene can be produced from mRNA strands
using the enzyme reverse transcriptase .
③ the gene can be also synthesised using an automated polynucleartide sequencer (gene machine ) .
, ① The gene is identified using a gene probe and then cut from the DNA fragment using a restric tion
enzyme .
DNA
probe a shor t single-stranded piece of DNA (50 80 nucleotides long) complimentary to a sec tion of DNA
being
-
investigated .
Restriction enzyme an
enzyme t h a t cuts DNA at a specific base sequence .
Most restriction enzymes m a ke a
staggered art to form sticky ends .
Sticky ends exposed bases a t the ends of cut DNA .
② A
copy of the gene can be produced from mRNA strands .
$ IN / $
'
*
isolate reverse
from cells
transcriptase PCR
purity
original mRNA with mRNA in cDNA many copies .
(n o introns
gene no introns
testy
(many , much
(2 copies) shor ter)
copies)
③ the gene can be synthesised using an automated polynucleotide sequencer . This i s a machine that can synthesise a
length of DNA froma base sequence t h at i s typed into i t Calla a gene machine )
The base sequence of genes is required for this .
In Vitro Gene Cloning Polymerase Chain Reaction )
CPCR
3 stages :
① Denaturation
② Annealing
③ Extension
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller meganlawrence999. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $5.16. You're not tied to anything after your purchase.
