Living Environment Translated English 2014 | Page 35

 Ecological succession is the gradual change from one plant
community to another.
 Primary succession begins in a place where no plants were
before.
 Secondary succession begins in a place that has soil and
was once the home of living things.
 A climax community has reached a stable stage of
ecological succession.
28.Humans cause many environmental problems:
a. Deforestation- cutting down of trees- causes increased
levels of carbon dioxide which leads to global warming.
b. Carbon dioxide is a greenhouse gas that helps warm Earth.
c. Burning fossil fuels ( coal, oil, natural gas) in cars and
industry leads to acid rain.
d. Over population leads to overuse of the earth’s natural
resources.
e. Humans cause air, water and soil pollution.
29. All ecosystems work toward sustainable development. This is the
practice of not using natural resources more quickly than they can
be replenished.

Unit 7: Evolution
A. Vocabulary
1. Evolution- a change in a species over time
2. The Earth is believed to be approximately 4.5 billion years old.
3. Jean B. de Lamarck – a scientist who proposed the Theory of Use
and Disuse. He said that changes in the environment caused the
organism’s behavior to change, leading to greater use or disuse
of a structure or organ. This was proven to be incorrect.