Transcript The Best Selection - Calgary Christian School

The Best Selection
Topic 6
Darwin’s Theory
• Charles Darwin is the main contributor to the
theory of natural selection.
• He sailed around the world collecting specimens
and data.
• He noticed the vast amounts of biological
diversity. He also noticed the finches.
• He continued to study the finches and created a
theory about how the fittest or the bestadapted organisms for a specific environment
survived.
Natural Selection
The theory, proposed by Charles Darwin, can be summed
up in four statements
1. All organisms produce more offspring than can
possibly survive.
2. There is incredible variation within each species.
3. Some of those variations increase the chances of an
organism surviving to reproduce.
4. Over time, variations that are passed on lead to
changes in the genetic characteristics of a species.
Selecting Desirable Traits
• Artificial Selection
– Process of selecting and breeding individuals with
desirable traits to produce offspring that have
these desired traits
– Ex. Horses, dogs, livestock, corn
Clones
• A genetically identical copy of
an entire organism or of its cells
or genes
• Cloning is the process of
creating a clone
• Ex. Cutting from a plant
•
•
http://on.aol.com/video/in-texas--cloned-horsesmove-on-to-competition-517503765
Cloning horses
• http://www.youtube.com/watch?v=vrQZSco77P
g
• The island trailer
Cloning in Focus
Web Quest
• http://learn.genetics.utah.edu/
Artificial Reproductive Technology
1. Artificial Insemination
– Sperm are harvested from a
desirable male and injected into a
female
– Ex. Livestock breeding
2. In Vitro Fertilization
– Fertilization that happens outside
the body, usually in a petri dish
(embryo is placed in female)
– Ex. Livestock breeding
• http://science.discovery.com/tvshows/brink/videos/brink-designerbabies.htm
• Designer Babies (5 min)
• Gattaca trailer
• http://www.youtube.com/watch?v=hWjlUj7Cz
lk
Genetic Engineering
• Definition: a technique involved in moving
pieces of DNA from one cell to another.
– Ex. Human-producing gene for insulin is inserted
into bacterial DNA. Bacteria reproduces quickly
and can produce insulin quickly and cheaply.
– Ex. Moving protein-making genes into the
transgenic (or genetically modified) animals who
will produce the human proteins necessary to aid
those who are deficient in a certain protein.
• Transgenic animals are created by inserting human
genes into the fertilized eggs of the animal.
Biotechnology in Food Production
• Ex. An “antifreeze” gene has been inserted into fish
from areas of decreasing populations.
• Ex. A cold-resistant gene from fish has been inserted
into tomatoes to help them withstand cold during
growth.
• Ex. Crops have been inserted with genes that help
them resist pests and insects.
• Ex. Cotton, corn and potatoes have been engineered
to produce Bt Toxin. Insects that eat the engineered
plant die, no pesticides are needed.
Biotechnology and Society
• Risks in Animals
– Decreased genetic diversity
– More susceptible to disease
– Cattle cloning – unsuccessful pregnancies, birth
defects and deaths
Biotechnologies in Society
• Risks in Plants
– Genetically engineered canola could interbreed
with weeds making their offspring resistant to
herbicides.
Review Questions
1. How does artificial selection differ from what you learned
about natural selection? Use examples.
2. How have reproductive technologies benefited
agricultural industries in Alberta? Provide examples. What
human needs do these technologies reflect?
3. What are some advantages of biotechnology such as
cloning? What are some disadvantages?
4. Scientists have created crops that contain a toxin that kills
any insect that eats them. Some farmers have been
growing corn plants that contain this toxin. Corn without
the toxin is a food supply to corn weevil, which destroys
the corn crop, and the monarch butterfly, which is a
protected species. What advice would you give to farmers
growing this crop?
The Clone Age (50 minutes))
• http://app.discoveryeducation.ca/search?Ntt=
clone+age