Unit A Lesson 16: Human Activities and Biotechnology
Completion requirements
Unit A Lesson 16: Human Activities and Biotechnology |
Learning Targets |
Inquiry Question: How do bacteria help a diabetic patient?
Humans have learned to use methods found in the natural world to help them in fields like medicine and agriculture.
Humans have learned to use methods found in the natural world to help them in fields like medicine and agriculture.
At the end of this inquiry, you should be able to answer the following questions:
- What is genetic engineering and biotechnology ?
- What is selective breeding?
- What is artificial insemination ?
-
What is
in-vitro fertilization ? -
What is
cloning
?
Page 66 to 71 in your textbook will help you answer questions
about the relationship between human activities and biotechnology.
Introduction
Artificial Selection
Long before the science of genetics, people wanted plants or animals with traits that were adapted better for their needs. In particular, farmers wanted plants or animals with specific traits to produce better yields or do certain tasks.
Farmers selected the plants or animals with the traits that they wanted to reproduce, such as horses with bigger bodies to pull plows, cows that produced more milk, and crops that had more kernels and resisted diseases. Eventually, their herds or crops reflected this method of selection. This process is called selective breeding or artificial selection. It is very different from natural selection because it can happen faster and it is driven by human desires rather than environmental conditions.
Do you have difficulty remembering the details of natural selection? Click here to return to Section 1, Lesson 5 to review Natural Selection.
Long before the science of genetics, people wanted plants or animals with traits that were adapted better for their needs. In particular, farmers wanted plants or animals with specific traits to produce better yields or do certain tasks.
Farmers selected the plants or animals with the traits that they wanted to reproduce, such as horses with bigger bodies to pull plows, cows that produced more milk, and crops that had more kernels and resisted diseases. Eventually, their herds or crops reflected this method of selection. This process is called selective breeding or artificial selection. It is very different from natural selection because it can happen faster and it is driven by human desires rather than environmental conditions.
Do you have difficulty remembering the details of natural selection? Click here to return to Section 1, Lesson 5 to review Natural Selection.
Watch
View "Evolution 1: Natural Selection vs. Artificial Selection" to examine the difference between natural and artificial selection.
Is a purebred dog better than a mixed-breed dog? Recall from Section 1 that variation is important not only for a unique world but it is safer for animals. Many purebred dogs are over bred to have certain characteristics.
For example, Chinese pugs are over bred for their stocky bodies, pushed-in noses, and big eyes. These desired characteristics produce health issues for the pugs. They often have trouble breathing through their nostrils and have other health problems. Watch the videos "Dog Breeds 101: The Pug” and “Science Today: Creating the Perfect Pet” to learn more about these problems.
For example, Chinese pugs are over bred for their stocky bodies, pushed-in noses, and big eyes. These desired characteristics produce health issues for the pugs. They often have trouble breathing through their nostrils and have other health problems. Watch the videos "Dog Breeds 101: The Pug” and “Science Today: Creating the Perfect Pet” to learn more about these problems.
Designer Dogs
In the past, dogs served various functions such as herding animals or guarding. Have you ever heard of designer dogs? These are bred specifically to be very cuddly, non-shedding, hairless, or very small. Teacup dogs are an example. They are so small that they can fit in a teacup.
In the past, dogs served various functions such as herding animals or guarding. Have you ever heard of designer dogs? These are bred specifically to be very cuddly, non-shedding, hairless, or very small. Teacup dogs are an example. They are so small that they can fit in a teacup.
What purpose do teacup dogs serve? Many people live in apartments in big cities, so a teacup dog does not make loud noise, is not expensive to feed, and does not need a great deal of space for exercise. However, they are plagued with health issues and genetic abnormalities.
What happens when humans select the traits they want and allow only the species with those traits to reproduce? What happens to the biodiversity of the world? What happens to the variation within the species?
The New Age of
Biotechnology
After human beings began to understand more about DNA, they began to manipulate (change) it. During recent decades, various genetic manipulations have occurred, such as genetic engineering, cloning, artificial insemination, and in-vitro fertilization.
Genetic Engineering
Genetic engineering is the intentional altering of DNA in a species or population of organisms. Genetic engineering has helped many people in positive ways. For example, it has helped patients suffering from diabetes who cannot produce their own insulin. Scientists have taken certain bacteria and inserted it with a gene to produce insulin. The bacteria reproduce so quickly that scientists can extract lots of insulin cheaply and at fast rates.
After human beings began to understand more about DNA, they began to manipulate (change) it. During recent decades, various genetic manipulations have occurred, such as genetic engineering, cloning, artificial insemination, and in-vitro fertilization.
Genetic Engineering
Genetic engineering is the intentional altering of DNA in a species or population of organisms. Genetic engineering has helped many people in positive ways. For example, it has helped patients suffering from diabetes who cannot produce their own insulin. Scientists have taken certain bacteria and inserted it with a gene to produce insulin. The bacteria reproduce so quickly that scientists can extract lots of insulin cheaply and at fast rates.
Watch
There are many other ways scientists have inserted genes into species and for various reasons. Watch the video "Science Creates Glowing Kittens, Monkeys and Sheep!" to see other examples of genetic engineering.
Does the answer to creating purple cows lie in the biotechnology of genetic engineering?
Can scientists isolate the gene for the colour purple and insert it into the DNA of a cow?
Cloning
Cloning is another form of genetic engineering. As discussed in Section 3 Lesson 1, a clone is a genetically identical copy of an entire organism or of its cells or genes. Scientists extract the DNA from a cell of an organism they want cloned and insert it into a donor egg that has had its DNA removed.
Then, they place the fertilized egg into a surrogate species so the egg can grow and become the exact copy of the donor that gave the DNA in the first place. Figure 1 shows cloning in a step-by-step form.
Scientists have been able to clone other species as well. Many types of plants clone very easily; in fact, the main method of reproduction for aspen trees is cloning. Since Dolly the sheep, scientists have been able to clone several other types of animals. Pigs, cows, dogs, and even camels. There have been no documented cases of human cloning, and the topic is very controversial in science circles and normal society.
Can you think of the advantages or disadvantages of cloning?
Figure 1 – The cloning of Dolly the sheep.
Watch
Dolly the sheep was the twin sister to her own mom! View the videos "Feb 24, 1997, ABC News" and "Cloning Dolly the Sheep" to learn how scientists can clone using DNA implantation!
Artificial Insemination
Artificial Inseminationis used mainly in livestock reproduction. Technicians collect sperm from the male and inject it into the female. Artificial Insemination is beneficial because the sperm of a strong male with desirable traits can be used to impregnate many females.
Artificial Inseminationis used mainly in livestock reproduction. Technicians collect sperm from the male and inject it into the female. Artificial Insemination is beneficial because the sperm of a strong male with desirable traits can be used to impregnate many females.
Watch
Watch "National Geographic - Meet the Super Cow"
to learn more about artificial Insemination.
In-vitro Fertilization
In vitro fertilization is the process of fertilization occurring outside the body. Often, it is done in a lab in a Petri dish. This form of genetic engineering is used widely in livestock breeding as well.
In vitro fertilization is the process of fertilization occurring outside the body. Often, it is done in a lab in a Petri dish. This form of genetic engineering is used widely in livestock breeding as well.
Watch
Watch the videos "How In Vitro Fertilization (IVF) Works" and "3D animation of how IVF works" to learn more about In vitro fertilization
The Case of the Purple Cow
Does the answer to producing purple cows lie in the biotechnology of genetic engineering? Can scientists isolate the gene for the colour purple and insert it in the DNA of a cow?
Does the answer to producing purple cows lie in the biotechnology of genetic engineering? Can scientists isolate the gene for the colour purple and insert it in the DNA of a cow?
A purple cow would be a cow with purple hair. The hair of mammals is coloured by depositing melanin onto the hair shaft as it is being produced by the hair follicle. For the colour purple to exist, blue pigment must be present. However,
no blue pigment occurs in mammals; mammals cannot produce blue hair or colours such as green or purple. Green requires blue to mix with yellow whereas purple requires blue to mix with red.
Because of this restriction on potential hair colour, scientists cannot create a purple coloured cow at this time. The purple cow will remain an elusive dream until scientists develop a biotechnological method that allows the production of purple in mammals.
But it is always fun to dream! How fabulous and unusual would a field of purple cows look?
Because of this restriction on potential hair colour, scientists cannot create a purple coloured cow at this time. The purple cow will remain an elusive dream until scientists develop a biotechnological method that allows the production of purple in mammals.
But it is always fun to dream! How fabulous and unusual would a field of purple cows look?
