Natural Selection and Selective Breeding

Question 1

What is evolution?

Answer 1

Change in the form of an organism over the course of time. Process by which species develop from earlier forms during the history of Earth

Question 2

Describe the mechanism of natural selection

Answer 2

1. There is variation within the species due to mutation
2. Changing conditions in the environment favours one particular form of the species

(The frequency of the favoured form increases and vice versa)

• Individuals better adapted are more likely to survive and reproduce
  3. Alleles are passed onto the offspring
  4. This repeats over many generations

Question 3

Full form of MRSA:

Answer 3

Methicillin-resistant Staphylococcus aureus

Question 4

The powerful insecticide against which, many insects have become resistant:

Answer 4

DDT

Question 5

What is selective breeding (artificial selection)?

Answer 5

A process where humans cross-breed individuals animals and plants that have been chosen because of their desirable characteristics

Question 6

Write down the steps of micropropagation:

Answer 6

Explants
⬇
Surface sterilized
⬇
Sterile agar
⬇
More explants
⬇
Another culture medium to induce root formation
⬇
Greenhouses (moist) ... in compost

Question 7

Advantages of micropropagation:

Answer 7

• Large no. of clones can be made rapidly
• Species difficult to grow from seeds/cuttings can be grown this way
• Plants can be produced at any time of the year
• Large no. of plants can be stored easily
• Genetic modification can be introduced into thousands of plants quickly after modifying only a few plants

Question 8

Sheep have been genetically modified to produce several human proteins example:

Where is it used?

Answer 8

Alpha-1-antitrypsin

Used to treat conditions such as emphysema and CF