biology processes

Malaria is spread by vectors:

1) mosquito sucks blood from human

2) if there are malaria parasites, they mate and move from mosquito's gut to salivary glands

3) mosquito bites another person & passes malaria parasites into their bloodstream

4) parasites move to liver where they mature and reproduce

5) new gen of malaria parasites migrates to blood & replicates in rbc, bursting them. Damage leads to characteristic malaria fever and can sometimes cause death

Prevent malaria / get rid of mosquitoes by...

> sleeping under mosquito nets

> insect repellents

> kill mosquitoes with insectiside

Passive immunity

...occurs when antibodies are put into body. Used when a quick response needed or when person has weak immune system.

E.g. pathogens or toxins in snake's venom acts fast, immune system can't make antibodies that fast to destroy pathogen, so injected with antibodies. Not have long-term protection against pathogen as wbc didn't make them themselves. After while, no antibodies for that antigen left in blood.

Immunisation/vaccination

Provides natural immunity from disease w/o being infected. It works as follows...

1) person is injected with dead or disabled pathogen.

2) Antigens trigger production of specific antibodies by wbc.

3) Long after, wbc remain in blood (memory cells). So more antibodies can be produced quickly if same detected again.

The eye!!!

Iris control light entering eye. Rays of light refracted by cornea, lens focuses light onto retina so rays…