Evolution

Question 1

What is evolution?

Answer 1

The change in the inherited characteristics of a population overtime. These changes happen through natural selection.

Question 2

What is natural selection?

Answer 2

The process where organisms that are best adapted to their environment survive, reproduce and passes on these genes to the offspring.

Question 3

What is the Theory of Evolution?

Answer 3

All species of living things have evolved from simple life forms that first developed over three billion years ago.

Question 4

What is the process of evolution?

Answer 4

1. Variation is present in a population due to random mutation.
2. Some organisms may have phenotypes that make them better adapted to their environment. This gives them a survival advantage because they have advantageous alleles.
3. At this point natural selection occurs: the better adapted organism is more likely to survive and reproduce, passing on the favourable alleles on to their offspring. (Those without the advantageous alleles are more likely to die out before they can reproduce).
4. Overtime, more individuals have the advantageous alleles.
5. If two populations become isolated from each other before natural selection occurs, they may eventually evolve into an entirely new species (speciation), where they can no longer interbreed to form fertile offspring.

Question 5

Speciation

Answer 5

The populations become extremely varied and successful interbreeding cannot happen anymore.

Question 6

Explain bacterial resistance to antibiotics (Example of Natural Selection)

Answer 6

1.There is variation amongst bacteria in a colony.
2. When bacteria are treated with antibiotics, some cells contain mutations which allows them to survive and reproduce, causing the number of resistant bacteria to increase.
3. Antibiotic resistance strains are an example of evolution, as they are more adapted to their environment to survive.

Question 7

Why does evolution happen quicker in bacteria than in humans?

Answer 7

Mutations occur quicker in bacteria, as they reproduce faster (binary fission)

Question 8

What is MRSA?

Answer 8

MRSA (methicillin-resistant staphylococcus aureus):
This bacteria is known as a superbug. It is very dangerous because it’s resistant to most antibiotics. It can be fatal if it enters the bloodstream.

Question 9

Why are resistant bacteria problematic?

Answer 9

It is a slow and expensive process to develop new antibiotics that can fight them, without damaging bodily cells.

Question 10

Three ways we can prevent the the spread of bacteria and the development of antibiotic resistance?

Answer 10

1. Avoid the overuse of antibiotics- doctors should only prescribe these when they need to.
2. Complete the full course of antibiotics so all bacteria are killed and so none survive to mutate and form resistant strains.
3. The agricultural use of antibiotics should be restricted as some bacteria can affect humans and animals.
   If given to animals too often, and then the bacteria becomes resistant to antibiotics, the bacteria can spread to humans e.g. during meat preparation and consumption.