THE VARIETY OF LIVING ORGANISMS

The Role of Adaptation and Selection in Diversity – Test it!

The Role of Adaptation and Selection in Diversity – Test it!

1.

Both eukaryotic cells and prokaryotic cells contain DNA.

a) Provide one way in which a DNA molecule is different in a bacterium and a human cell.

b) A bacterium (X) becomes resistant to antibiotics because of a mutation in its DNA. In what two ways X can pass this gene resistance on?

i. _________________________
ii. _________________________

c) A person becomes infected with species Y, some of which are resistant to penicillin. What will happen to the bacteria of species Y which are resistant to penicillin?

2.

There’s been an increase in patients catching MRSA in some hospitals.

a) Suggest two ways this transmission could be reduced?

i. __________________________________________________
ii. ________________________________________________

b) Why do antibiotic resistant genes spread so rapidly within a population?

ANSWERS

1. Answers include:

a)

i. Bacteria contains DNA which is circular

ii. Bacteria DNA is not associated with proteins

iii. Bacteria DNA doesn’t contain introns

b)

i. vertical transmission

ii. horizontal transmission

c) The penicillin resistant bacteria will survive and not be killed off. They’ll then reproduce and increase in population.

2. a)

i. isolation or quarantine
ii. screening or testing
iii. sterilisation

b) Resistance to antibiotics is a useful characteristic and so the gene will survive and spread on to further generations.