SELECTIVE BREEDING

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SELECTIVE BREEDING GENETIC ENGINEERING

• 3.f. Develop a logical argument for or against
  research conducted in selective breeding and
  genetic engineering, including (but not limited
  to) research conducted in MS.

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Bellwork 1/5

• Write a paragraph (at least 5 sentences) about
  your Christmas Break

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Selective Breeding Genetic Engineering

• Selective breeding genetic engineering are 2
  scientific techniques in which humans try to
  produce offspring with desirable traits

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What is selective breeding?

• Definition
• Selective breeding is where humans select (chose)
  2 animals with desired traits breed (mate) them
  trying to produce offspring with the desired
  traits of both parents

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Selective Breeding

• Typically, strains which are selectively bred are
  domesticated
• Over many generations, the practice leads to the
  development of strains with the desired
  characteristics

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Examples of selective breeding

• Intentionally mating 2 dogs in order to achieve
  or eliminate a specific trait
• A farmer saves seed from a hearty crop to replant
  the next year
• Dogs are bred for competition or for hunting
• Cows can be bred to increase muscle mass or milk
  production

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Examples of Selective Breeding

• Dogs are a good example of selective breeding.
  Gamekeepers who hunted birds for leisure in the
  1800s wanted a dog that didnt actually exist.
  So, they selectively breed a mastiff and a
  bulldog to get the qualities that they wanted.
  Mastiffs were big, strong good companions, but
  they lacked in speed and aggression. The bulldog
  however was aggressive and fast but lacked in
  strength. The selective breeding process
  eventually produced a bullmastiff which was
  large, quick, strong, aggressive

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Bullmastiff
Big, strong good companion (not aggressive or
fast)
Aggressive fast (not big strong)
When selective breeding these 2 dogs, we get a
Bullmastiff
Large, quick, strong aggressive dog
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Example of Selective Breeding in Cattle
Brahman cattle good resistance to heat, but poor
meat
English shorthorn cattle good beef, but
poor heat resistance
When selecting to breed these 2 animals we get
a Santa Gertrudis cattle Result good beef
AND resistant to heat
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Selective Breeding in Crops
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Selective Breeding of Lions Tigers LIGER

• Ligers are the worlds biggest cats
• Larger than their parents with the strength of a
  lion and speed of a tiger combined
• An average male liger stands almost 12ft on its
  hind legs weigh up to half a ton (twice the
  weight of a wild lion or tiger)

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How did the liger appear?

• If the father is a lion the mother is a tiger,
  the offspring are known as ligers and the pairing
  results in gigantism

Strong but lacks speed
Fast but not as strong
Ligers are fast strong twice as big as parent
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Why do people selectively breed animals plants?

• To make animals grow bigger, faster, prettier
  stronger
• To make plants grow bigger, faster, prettier
  produce more crops

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Pros of Selective Breeding

• Benefits
• Farmers can produce crops with higher yield
• More fruit or vegetables on a stalk
• Farmers can produce animals that grow more meat,
  more milk, more eggs, faster stronger
• Can produce friendlier and prettier pets

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Cons of Selective Breeding

• Disadvantages
• Loss of genes in a population
• By not allowing some animals to breed, their
  genes could be lost forever in a population
• Take Hitler for example, he tried to kill all
  Jews, therefore, trying to eliminate the genes
  and all Jews from the planet
• Animal discomfort
• Farmers breed cows to have large utters, so now
  some cows have difficulty walking have health
  problems
• Some chickens are too heavy to stand, so they
  have to lay down all the time
• Can lead to inbreeding
• In order to create a certain type of animal
  through selective breeding, sometimes brothers
  sisters of a population will mate to pass on
  favorable traits, and this can lead to bad health
  problems for children of inbreeding

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Bellwork 1/6

• Define selective breeding.

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Classwork 1/6

• With a partner, come up with at least 5 specific
  examples of selective breeding.
• IF YOU FINISH BEFORE I CALL TIME, YOU NEED TO
  COME UP WITH MORE UNTIL I TELL YOU TO STOP.

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GENETIC ENGINEERING

• Genetic engineering is a lot like selective
  breeding but a much faster process
• Definition taking favorable genes from one
  organism and implanting it into another
  organisms DNA
• This can only be done in a laboratory with
  special equipment

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Examples of Genetic Engineering

• People have taken the insulin making gene from
  humans and inserted it into bacteria causing
  bacteria to make human insulin
• Why?
• Bacteria can reproduce quickly causing them to
  produce insulin at a much faster rate

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Examples of Genetic Engineering

• People have taken bad genes (genes which cause
  cancer and other diseases) out of a person and
  inserted healthy genes into a person to cure them
  of diseases
• However, they may be cured of that disease but
  get another worse disease because of being
  implanted with the other gene

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Examples of Genetic Engineering

• People have taken a weed resistant gene and
  inserted the gene into certain crop plants
• Now farmers can spray weed killer on the crops to
  kill the weeds, but the spray will not affect the
  crops.
• The crops will grow better and bigger because
  weeds do not take away sunlight, nutrients, and
  water
• However, this gene has leaked over into the weed
  population sometimes and caused the weeds to be
  resistant to herbicides (weed killer spray)

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Examples of Genetic Engineering

1. People have inserted genes into crops to make the
   crops resistant (poisonous) to pests, but are
   harmless to humans (we think)

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Genetically Engineered Fish

• We have inserted genes into fish to make them
  grow twice as big and twice as fast

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Genetically Engineered Chickens

• We have inserted genes into chickens to make them
  grow twice as big and twice as fast. They are so
  big they cant walk.

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Genetically engineered crops

• Humans have injected genes into crops to make
  them grow in colder environments
• Humans have injected genes into crops to make
  them grow in dry (drought) environments

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Genetically Engineered Pigs

• Humans inject genes into pigs DNA in order for
  the pig to grow human-like organs, so people can
  transplant these organs into people who need them

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Genetically Engineered Mice

• Humans inject genes into mice to make the mice
  grow human ears for cosmetic purposes

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Genetically Engineered Vaccines

• Genetically engineered vaccines may be safer
  because they do not use live viruses like
  traditional vaccines do

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Genetic Engineering

• Genetic engineering may work wonders but it is
  all a process of manipulating the natural

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The Pros Cons of Genetic Engineering
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Pros Include

• Humans have made crops with better taste,
  nutrition, and growth rate
• Humans have made pest resistant crops and crops
  with longer shelf life
• Humans have been able to produce new foods
• Foods which couldnt be reproduced in nature
• Humans can help cure certain disease
• Boosts positive traits and suppress negative ones

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Cons Include

• By making plants bigger, taste better, and better
  appearance we have accidentally made some crops
  allergenic to people
• By making plants bigger, taste better, and better
  appearance we have accidentally made some crops
  have less nutritional value
• Accidental gene transfer
• Such as when we inserted genes into crops to make
  them resistant to pest or herbicides, the genes
  leaked over into weeds and made them resistant to
  pest and herbicides too

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Cons Include

• Genetic engineering in human beings can have
  certain side effects
• While treating one defector disease, the genetic
  engineering may lead to another disease which
  could be worse
• Whats next?
• Will people try to insert genes into babies to
  have children which are smarter, muscular,
  prettier, certain color eyes, certain color hair,
  and talented
• Playing God

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Quiz

1. Define selective breeding.
2. List 3 examples of selective breeding.
3. List 2 benefits of selective breeding.
4. List 2 disadvantages of selective breeding.
5. Define genetic engineering.
6. List 3 examples of genetic engineering.
7. List 2 benefits of genetic engineering.
8. List 2 disadvantages of genetic engineering.

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Bellwork 1/7

• List benefits and disadvantages of selective
  breeding.
• List benefits and disadvantages of genetic
  engineering.