Biology

it contains more organisms

it has greater energy source

it is not easy to destroy

every organism has an alternative source

New leaves are formed

The trees die off

The undergrowth increases

The ground becomes bare

Possession of long tail

Possession of claws

Possession of teeths

counter shading in coat colour

Syphilis

Malaria fever

Tuberculosis

Acquired Immune Deficiency Syndrom

industrial chimneys, burning fossil oils and river dam

sulphur dioxide, acid rain and pesticides

sulphur mines, vehicle exhausts and aerosols

sewage, smoke and old vehicle