SB4 Natural selection and genetic modification

Question 1

Explain how antibiotics work

Answer 1

The bacteria infects the body, when white blood cells detect the bacteria in the body they try and defend the body from the bacteria, if the white blood cells cannot do that the doctor will then often prescribe antibiotics in order to get rid of the bacteria. A lot of the bacteria dies, there are few bacteria cells which survive due to a mutation in their genes causing them to be antibiotic resistant. The bacteria that is resistant multiples until there is a lot of them and it continues to infect the body.

Question 2

Describe what is meant by Prokaryotes and Eukaryote.

Answer 2

Prokaryotes have no nucleus and are small, single cells(unicellular) only coding DNA.

Eukarya(AKA Eukaryote) contain a nucleus are multicellular and contain unused sections in genes and non-coding DNA.

Question 3

What does it mean to do selective breeding?

Answer 3

Selective breeding is where an animals with certain desirable characteristics are bred together in order to create offspring that inherit their characteristics

Question 4

What does it mean to do genetic engineering?

Answer 4

Genetic engineering involves modifying the genome of an organism by introducing a gene from another organism to give a desired characteristic. Some examples of this would be speed, muscles or other traits.

Question 5

What are tissue cultures?

Answer 5

When you take a small piece of tissue from the parent plant and place it in an agar growth medium containing nutrients and auxins. Over time, the tissue develops into tiny plantlets which are planted into compost so that they can grow into clones of the original parent plant.

Question 6

What is evolution?

Answer 6

Evolution helps us to understand relationships between difference species of organisms. It explains how new species evolve, it also explains how different species adapt to changes in their environment.

Question 7

What do farmers use fertilizers for?

Answer 7

Fertilisers contain mineral ions such as nitrogen and potassium and phosphorus, the plants absorb minerals from the soil to make health new cells. Fertilisers help us to absorb the growth and yield of crops.