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Question 1

How are new breeds and varieties of organisms created?

Answer 1

1. Natural selection - nature chooses who is going to survive and pass on the favourable allele
2. Artificial selection - humans choose the animals with the favourable characteristics and breed them together
3. Genetic engineering

Question 2

What is selective breeding?

Answer 2

1. Humans choose the organisms with the favourable characteristic and put them together to breed.
2. They then choose the offspring with that particular characteristic and put them together to breed.
3. This process is repeated until they have organisms with that specific characteristic.

Question 3

What is genetic engineering?

Answer 3

A process that changes the DNA of an organism by adding extra genes for a favourable characteristic.

Question 4

What are organisms that contain DNA from another organism called?

Answer 4

Transgenic.

Question 5

What are GMO’s?

Answer 5

GMO’s (genetically modified organism) are organisms that had their DNA changed.

Question 6

Why are GMO’s created?

Answer 6

1. For the organism to produce certain substances (e.g. beta-carotene)
2. For the organism to have characteristics that allow survival in different conditions (e.g. tomatoes not to freeze at extremely low temperatures)

Question 7

What are three uses of GMO’s?

Answer 7

1. Create golden rice to produce beta-carotene to be taken by humans (humans that lack beta-carotene cannot make Vit A which can cause blindness)
2. Create organisms that are resistant to disease-causing organisms
3. Create organisms faster and to be larger than normal so that they provide more yield to feed the growing population

Question 8

What is tissue culture?

Answer 8

The growing of cells or tissues in either a liquid with nutrients or in a special gel called agar with nutrients.

Question 9

Where are stem cells found, what are they and what can they do?

Answer 9

Stem cells can be found in plants and animals. They are unspecialised cells that can differentiate into other cells and form tissues.

Question 10

What are the two ways of performing tissue culture with plants?

Answer 10

First way is by using a piece of the plant:
1. Put the plant in bleach solution to sterilise it so that all the microorganisms such as bacteria die and won’t compete with the plant for nutrients.
2. Place the piece of plant into a sterile agar (medium) that contains all nutrients needed for growth.
3. Add special hormones to the agar so that the plant develops shoots and roots.
4. Once the plant has grown enough then they plant them into soil or compost.

Second way is by using plant cells:
1. Put the plant in bleach solution to sterilise it so that all the microorganisms such as bacteria die and won’t compete with the plant for nutrients.
2. Take some cells and put them into a sterile medium so that they grow into a callus (a ball of unspecialised cells).
3. The callus will then develop plantlets.
4. Treat the plantlets with hormones so that it develops roots and shoots.
5. Take the plantlets and separate them and put them into a sterile medium so that they can grow.
6. Once the plants have grown enough, then they plant them into soil or compost.