4.6 Selective breeding and genetic engineering Flashcards Preview

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Flashcards in 4.6 Selective breeding and genetic engineering Deck (21)
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Selective breeding can also be called...

artificial selection


Give examples of organisms that have been selectively bred.

1. Animals that produce more meat or milk.
2. Crops with disease resistance.
3. Dogs with a good, gentle temperament.
4. Decorative plants with big or unusual flowers.


Describe the basic process of selective breeding.

1. Select individuals from your existing stock that have desirable characteristics.
2. Breed these individuals together.
3. Select the best offspring and breed them together.
4. Continue this process of several generations until the trait gets stronger and stronger.


Another word for characteristics is...



What is meant by 'yield'?

Amount of product made e.g. yield of wheat or meat produced.


How many years have we been doing selective breeding for?



What is meant by agriculture?



What is the main draw back of selective breeding?

1. A reduction in the gene pool.
2. This could make a population vulnerable to disease.


What is meant by the 'gene pool'?

The number of alleles present in a species population.


What is 'inbreeding'?

Where closely related plants are bred.


What is the negative consequence of inbreeding?

There is an increased risk of offspring developing health problems e.g. genetic diseases.


What is genetic engineering?

Where genes responsible for a desirable characteristic are transferred from one organism to another.


An organism that has received a gene from another organism is called a...

transgenic organism


Describe the basic process of genetic engineering.

1. A useful gene is isolated from one organism's genome enzymes.
2. The gene is inserted into a vector (a virus or bacterial plasmid).
3. The vector is introduced into the cells of the organism that you are modifying at an early stage of development (embryo).


When should new genes be added to an organism during genetic engineering?

At an early stage of the organisms development e.g. when it is an embryo.


How are genes cut from DNA?

Using enzymes


The vectors that are used in genetic engineering can be...

viruses or bacteria


List 3 examples of organisms that have been genetically engineered.

1. Bacteria produce human insulin to treat diabetes.
2. Genetically modified crops that produce large amounts of fruit, are disease and insect resistant.
3. Sheep that produce drugs in their milk.


The idea of inserting working genes into people with genetic disorders is called...

gene therapy


What are the pros of genetically modified (GM) crops?

1. Increased crop yields so more/cheaper food.
2. Crops can be engineered to produce more nutrients.
3. GM crops are already being grown without any problems.


What are the cons of genetically modified (GM) crops?

1. GM crops may affect the number of wildflowers due to competition.
2. If fewer wild flowers, insect biodiversity could be reduced.
3. Herbicide resistant genes may 'escape' into other plants e.g. weeds, which would result in 'super weeds'.
4. Some people think they might be unsafe and have bad effects on human health e.g. allergies.