Transcript Reproductive Technologies in Agriculture

Reproductive Technologies in
Agriculture
BC Science Probe 9
Section 3.5
Pages 93-97
Reproductive Technologies in
Agriculture
• Living in and around Agassiz, agriculture is an
important part of our community; what are
some of the different technologies used in
agriculture and how do they apply to sexual
and asexual reproduction?
Selective Breeding
• This is the most commonly used reproductive
technique.
• This is how it works:
1. The breeder takes two individuals from the same
species (plant or animal) that have the desired
characteristics and breeds them with each other.
Selective Breeding
2. The breeder selects the offspring with the desired
characteristics of the parents and breeds them
with other individuals who also have those traits.
3. This continues for multiple generations, and
eventually all of the offspring will have the
desirable traits.
Selective Breeding
Selective Breeding
• Some more examples:
– Beef cattle have been
selectively bred to produce
high quality and quantity of
muscle.
– Canola plants have been bred
to improve the quality of the
oil.
Artificial Vegetative Reproduction
• In chapter 2 we talked about vegetative
reproduction.
• Some plants are able to reproduce by taking
cuttings from a desirable plant and growing a
new, genetically identical one.
Artificial Vegetative Reproduction
• You can only take so many cuttings from a
plant, so scientists came up with a better way
to produce clones:
– They take individual cells from the plant they want
to clone and can grow them in a Petri dish that
contains nutrients and growth hormones!
– Once this tiny cell grows into a seedling with roots
it can be transplanted into the soil.
Artificial Vegetative Reproduction
• Grafting is another method.
– It is when a branch from a tree that produces
good fruit is attached to the trunk of another tree.
– This other tree usually has good roots, but maybe
its fruit isn’t great.
Artificial Vegetative Reproduction
– The bark on the
branch will
eventually fuse
with the bark on
the trunk and the
branch will grow
to produce fruit.
– This is very
common in
apples, grapes and
peaches.
Artificial Insemination
• This is when a veterinarian collects sperm
from a male animal and inserts in into a
female animal of the same species.
• This is used often in selective breeding for
desirable traits and for speed as it often
produces results faster that conceiving the
normal way.
Artificial Insemination
• This is used often in dairy cows and also in
zoos.
– This helps to increase the population of
endangered species.
• Sperm are collected from the desired male
then frozen for transport or saved until the
female ovulates.
In Vitro Fertilization
• This is when both the sperm and the eggs are
collected from the male and the female
animals.
• Fertilization happens in the lab in a Petri dish.
• Then the embryos are inserted into females.
– These females are usually surrogate mothers
because they are not genetically related to the
embryos.
In Vitro Fertilization
• Both artificial insemination and in vitro
fertilization are advantageous to farmers
because more offspring with desirable traits
can be produced than there would be
naturally.
Hatcheries
• Since salmon use external fertilization in the
wild, sometimes they are not very successful.
• Hatcheries help to ensure a higher rate of
survival in these wild fish populations.
Hatcheries
• Just before they are ready to reproduce, both
the male and the female fish are caught.
• The eggs and sperm are collected and mixed
together in a container.
• Then the fertilized eggs are incubated the fed
until they are ready to be released into the
wild.
Recombinant DNA
• This technology involved combining genes
from different organisms into a single
molecule of DNA!
– Recombinant DNA can be used to produce certain
traits in organisms.
– It can also be used to produce substances from
organisms.
Recombinant DNA
• Bacteria are often used to produce substances
with recombinant DNA:
– Human growth hormone
• To treat some forms of dwarfism
– Insulin
• To treat diabetes
– Vaccines against Hepatitis B
Genetic Engineering
• Organisms with genes that have been
intentionally altered are called genetically
modified organisms (GMOs).
Genetic Engineering
• In the 1960’s, Canadian scientists used
selective breeding to improve the colour and
the flavour of the oil they produced.
• More recently, GM canola plants have been
produced to resist drought and disease.
Genetic Engineering
Genetic Engineering