Download 4.4 Genetic Engineering and Biotechnology

Biology Journal 2/3/2014
What does a restriction enzyme do?
How is it used in electrophoresis to
make a DNA profile?
Biology Journal 2/4/2014
What is a karyotype?
What can it be used to find?
A karyotype can be used
to find chromosomal
mutations and also
gender.
Having an extra 21st
chromosome (called trisomy 21)
causes Down syndrome. This is
caused by nondisjunction during
meiosis
Different organisms have different numbers of
chromosomes. How many do humans have?
fruit fly karyotype
Human karyotype. What is the gender? Are there any chromosomal mutations?
Is there a chromosomal mutation in this
karyotype? If so, what would we call it?
Yes! This is nondisjunction (specifically, Kelinfelter
syndrome), because this person has 3 sex
chromosomes. Thus, the sex chromosomes failed
to separate properly during anaphase (separation of
sister chromatids) of meiosis I or meiosis II.
4.4 Genetic Engineering and Biotechnology
Assessment statement
4.4.1
Outline the use of polymerase chain reaction (PCR) to copy and amplify
minute quantities of DNA.
4.4.2
State that, in gel electrophoresis, fragments of DNA move in an electric
field and are separated according to their size.
4.4.3
State that gel electrophoresis of DNA is used in DNA profiling.
4.4.4
Describe the application of DNA profiling to determine paternity and also
in forensic investigations.
4.4.5
Analyse DNA profiles to draw conclusions about paternity or forensic
investigations.
4.4.6
Outline three outcomes of the sequencing of the complete human
genome.
4.4 Genetic Engineering and Biotechnology (continued)
Assessment statement
4.4.7
State that, when genes are transferred between species, the amino acid sequence of polypeptides
translated from them is unchanged because the genetic code is universal.
4.4.8
Outline a basic technique used for gene transfer involving plasmids, a host cell (bacterium, yeast or
other cell), restriction enzymes (endonucleases) and DNA ligase.
 The use of E. coli in gene technology is well documented.
 Most of its DNA is in one circular chromosome, but it also has plasmids (smaller circles of
DNA).
 These can be removed and cleaved by restriction enzymes at target sequences.
 DNA fragments from another organism can also be cleaved by the same restriction enzyme,
and these pieces can be added to the open plasmid and spliced together by ligase.
 The recombinant plasmids formed can be inserted into new host cells and cloned.
4.4.9
State two examples of the current uses of genetically modified crops or animals. Examples include:
 salt tolerance in tomato plants
 synthesis of beta-carotene (vitamin A precursor) in rice
 herbicide resistance in crop plants and
 factor IX (human blood clotting) in sheep milk
4.4.10 Discuss the potential benefits and possible harmful effects of one example of genetic modification.
4.4 Genetic Engineering and Biotechnology (continued)
Assessment statement
4.4.11
Define clone.
4.4.12
Outline a technique for cloning using differentiated animal cells.
4.4.13
Discuss the ethical issues of therapeutic cloning in humans. Therapeutic
cloning is the creation of an embryo to supply embryonic stem cells for
medical use.
Polymerase Chain Reaction
•Used to make more copies of DNA, called
amplifying.
Steps:
1. Heat DNA to unzip it
2. Cool DNA and add
primers (sequences
of DNA where
replication can start)
3. Add Polymerase (the
enzyme that copies
DNA)
4. Repeat!
What is the relationship between the
daughters and these parents?
DNA Profiling
•Makes a “DNA fingerprint.” Can be used to
compare identity, and relationships.
Oops! You forgot to add the restriction
enzyme to the DNA before loading it into the
electrophoresis chamber. What do you think
would happen?
Oops! You hooked up the electric cords to
the electrophoresis chamber backwards,
reversing the + and – charge. So, what do
you think would happen?
Practice IB test question
Practice IB test question
Practice IB test question
Practice IB test question
Practice IB test question
Practice IB test question
Mom
Dad
Human Genome Project
Goal: Identifying the entire sequence (ATCG’s) and
location of every human gene (there are about
30,000).
Outcomes:
1. It’s not that simple! Traits are
complex outcomes of gene
interactions (1 gene ≠ 1 trait).
2. We can use genes to: diagnose
diseases, risks, and prescribe
drugs more effectively.
3. We can compare the genomes
between species to learn about
evolution
3 Sad Surprises about the Human Genome Project
Science Guy explains the significance of the Project and its shortcomings.
https://www.youtube.com/watch?v=F5LzKupeHtw
The Story of You
A cartoon briefly summarizing the history of genetics, leading to the Project, and its
consequences.
https://www.youtube.com/watch?v=VJycRYBNtwY
Explaining the Human Genome Project
A brief summary of the time-consuming initial reading of the genome, to the computerdriven advancements.
https://www.youtube.com/watch?v=N0QZDOcqyO4
3D Animation: DNA
Review of transcription and translation, emphasizing what genes can tell us.
https://www.youtube.com/watch?v=VJycRYBNtwY
Genetic Engineering
The genetic code is universal (DNA can be read and
translated to proteins by any species). Thus genes
can be transferred from one species to another.
Take out the gene
(DNA sequence) for a
glow-in-the-dark
protein, and insert it
into another organism.
Gene Transfer
An example: Engineering E. coli that creates human insulin
Examples of Transgenic Orgamisms
4.4.9 State two examples of the current uses of genetically modified crops or animals.
Organism
Rice
Corn
Tomato
Use
Staple crop that contains vitamin A
A crop that produces proteins that make
insects not eat it
Salt-resistant crop
Sheep
Livestock that produces human clotting
factors in its milk
Pigs
Livestock that contains few antigens, so
tissues can be transplanted into humans.
Cloning
A clone is any organism with DNA identical to
another.
•Reproductive cloning: making a new “baby” copy
of an adult organism.
•Therapeutic cloning: growing (culturing) some cells
with the same DNA as an adult.
4.4.8 Outline a technique for cloning using differentiated animal cells.
What kind of cloning is shown here? How do you
know?
The Ethics of Cloning
Would you make a clone of yourself to…
•Treat a horrible
disease that you
have?
•Save your own life?
•Save the life of a
loved one?
•Reproduce?
In 2012, this couple paid $155,000
to clone their beloved pet dog who
died suddenly.
(http://www.dailymail.co.uk/news/article-2141574/First-couple-clonepet-dog-paid-155-000-job-say-new-pup-mannerisms-deadLabrador.html)