Transcript Genetics powerpoint

Genetics
What is Albinoism?
• Albinoism is a recessively inherited
condition affecting about one in 17,000
people. A person who inherits albinism
usually inherits a recessive gene for the
condition from each parent, though this is
not the case in ocular albinism. The
condition, though often fatal in other
animals, has almost no impact on life
expectancy or overall health in humans,
but does affect vision to varying degrees.
Albino Characteristics
• Little or no pigmentation in the eyes,
skin, and hair (or in some cases in the
eyes alone).
• The altered gene does not allow the
body to make the usual amounts of a
pigment called "melanin".
• True albinos have pink eyes and very
light skin and hair.
These are not
albinos; they
have pigmented
eyes.
White Bengal
Tiger
White Bluebonnets
Pink Bluebonnets
Mutations
A change in genetic
information
•Can occur randomly (naturally)
•Or can be deliberately caused in the laboratory
by scientists
•Inherited
•Not always harmful
http://www.accessexcellence.org/
Helpful Mutations
-Some mutations are necessary for the
survival of a species.
-Mutations are the driving factor behind
evolution
-These are also known as adaptations
Ex. Bacteria that are unaffected by
antibacterial soap.
Sickle Cell Anemia
• This genetic mutation first was discovered
in Africa.
– The red blood cells of individuals with this
characteristic are the abnormally shaped.
– This was an advantage because people with
this mutation are immune to malaria which is
one of the leading causes of death in Africa
– People with Sickle cells lived longer on
average because of their immunity to malaria
which made them produce more children with
the trait.
Camouflage
• Some species are born with specific color
patterns which make them more likely to
survive then others of the same species.
Longer life spans often lead to a greater
chance of your genetic material being
passed on to offspring because more
children are born.
Camouflage Images
Camouflage images continued
Mimicry
• This is an individual of a species acts like
another object, usually to hide from
predators or to ambush prey.
• This increases the survival chances of an
individual.
More Mimicry
Evolution
Evolution is the change in the inherited traits
of a population of organisms through
successive generations. When a population
splits into smaller groups, these groups cangiven sufficient time and enough
environmental differentation—evolve
independently and diversify into new species
Key Points
• Charles Darwin’s main points on evolution
– Species change over time
– All organisms share common ancestors with
all the other organisms that exist
– Evolution takes a long time to happen, over
many successive generations
• Today scientist have seen this happen much more
quickly
Natural Selection
4 components of natural selection
• Variation-organisms exhibit differences
within a species
• Some traits are consistently passed on
• Each generation experiences high
mortality due to a struggle for resources
• Individuals possessing traits for being well
suited to survive will do so and have a
greater chance for passing on their traits
to many offspring
Summary of ideas
• From one generation to the next, the
struggle for resources (what Darwin called
the “struggle for existence”) will favor
individuals with some variations over
others and thereby change the frequency
of traits within the population. This
process is natural selection. The traits
that confer an advantage to those
individuals who leave more offspring are
called adaptations. Examples Evolution
and Natural Selection
HUMAN INTERVENTION
Selective breeding
Selective breeding- this is the process of
breeding animals or plants to acquire a
specific trait.
A) This has been done to many species
throughout history but none more
prevalently then the Dog
B) Our plethora of modern day dog
breeds is believed to have originate
from one specific type of dog. The Wolf.
Hybrid Plants and Animals
A hybrid is a cross between
two species of organisms
that would normally not
interact with each other in
the wild
The Liger
• The Liger is the result of breeding a female Tiger to a
male Lion.
• The liger has both stripes and spots. The stripes are
inherited from its tiger parent and the spots from the lion
parent.
• On their hind legs, ligers stand approximately 12 feet
tall. At most, ligers may weigh up to 1,000 pounds.
The Cama is the result of breeding a Llama
to a Camel.
Parents in background of picture.
The Zebroid is the result of
breeding
a female Horse and a male
Zebra.
The Zedonk / Zonkey is
the result of breeding
a female Donkey and
male Zebra.
Geep - These are the result of a sheep
and a goat.
The Mule is the result of breeding a female horse
(mare) to a male donkey (jack). The
mule is superior to the horse in strength,
endurance, intelligence and disease resistance.
Maroon & Red Bluebonnets
Strange New Hybrids
Zant
Two Clobster
Squiger
African Retriever
African Terrier
Caowl
Bat Frog
Gorrelephant
California Condor
Cloning
Futhi
What is Cloning?
• Duplicating a person e.g.
identical twins.
This is called “Reproductive”
cloning.
• Duplicating part of a person e.g.
a heart or
liver, or even just a few cells. This
is called
“Therapeutic” cloning.
What does this mean?
Usually we get half our genetic
information
from each of our parents:
50% + 50% = 100%
In Cloning…
• 100% of genetic information
comes from
one individual. E.g.
Could
Make
Is a clone genetically
identical?
Almost – but not quite.
Even identical twins are different due to
the
slight differences in the environment
that they experience.
Clones would be even more different
as they would live in a very different
environment and time as a form of
“delayed identical twin”.
Therapeutic Cloning
• Made in the same way as reproductive
cloning except the embryo is not
implanted;
• Stem cells are harvested from the
embryos
which kills it;
• The stem cells are used to grow
different
types of cells;
Hot Debate
Stem Cell Research
Embryonic V.S. Adult
Reactions: The Cloning Debate
When do you believe life begins?
Is Cloning Allowed?
Different countries have different laws
for the different types of cloning.
Some countries (led by USA) want a
global ban on all types of cloning,
while others want a ban on certain
types.
In South Africa there are currently
no laws
against cloning.
Questions to Ponder
• Do you think cloning is ethical for
humans?
• If you had a clone would it be your
child or
your delayed twin?
• Does a clone have a soul?
• What about all the duds?
• What about creating clones for
organs?
• Who should decide who is cloned?
More Questions
Ethical questions cont…
• Who should have access to cloning
technology – only people with good genes?
• Who should pay for the cloning?
• Should we be able to use this technology to
design our children? (Gattaca)
• Who does genetic information belong to?
• Should people with genetic diseases be
cured? Should they have children?
GENETIC ENGINEERING
The selective, deliberate change of
genes (genetic material) by man.
The technique of removing,
modifying or adding genes to a
DNA molecule in order to change
the information it contains.
What is a transgenic?
• Concept Based on the Term Transgene
Transgene – the genetically engineered gene
added to a species
Ex. – modified EPSP synthase gene (encodes a
protein that functions even when plant is treated with
Roundup)
Transgenic – an organism containing a transgene
introduced by technological (not breeding)
methods
Ex. – Roundup Ready Crops
Why are Transgenics
important?
• We can develop organisms that express a
“novel” trait not normally found in the
species
• Extended shelf-life tomato (Flavr-Savr
Herbicide resistant soybean
(Roundup Ready
Bright face of genetically modified corn plant: pestinfected non-GM (left) and pest-free GM plant (right)
planted side-by-side in a field trial. (photo: Dr. Yu Jialin,
China Agricultural University)
Agriculture Transgenics On the
Market
Insect resistant cotton – Bt
toxin kills the
cotton boll worm
• transgene = Bt protein
Virus resistance - papya
resistant to
papaya ringspot virus
• transgene = virus coat
protein
French genetic researchers created Alba for artist Eduardo Kac. Thanks to genes
borrowed from a jellyfish, the albino rabbit glows green when placed under special
lighting. In regular light, Alba appears like any other furry white rabbit. But place her
under a black light, and her eyes, whiskers and fur glow a otherworldly green.
"Glow in the dark" fish. these genetically modified fish were developed by a Taiwanese
aquatic firm, Taikong Group. They are planning to reproduce these fish in numbers and
sell them for pets.
http://www.fluorescentpets.com/index.htm
Scientists in the agriculture department of the Hebrew University in
Rehovot have genetically engineered a chicken that has no feathers.
Some Ag Biotech Products Are
Discontinued, Why?
Poor Quality
• Flavor Saver tomatoes (Calgene)
Negative Consumer Response
• Tomato paste (Zeneca)
Negative Corporate Response
• New Leaf (Monsanto)
Universal Negative Publicity
• Star Link corn (Aventis)