a.

Main Idea Check


Here are the main ideas for this passage. Write the correct paragraph number beside its main idea.


This paragraph gives an example of a tropical plant that is of great medicinal value to humans and
another plant of potential value that is threatened by extinction.


Economic development is necessary if the loss of the world's biodiversity is to be halted.


The rapid loss of tropical species can be slowed if we address all its causes.


To preserve tropical biodiversity, we also need to speed up research into the species that have not
yet been studied.

Tropical forests are rapidly being destroyed by humans.


The wild species of the tropical forests are an underused and very valuable source of crop plants
for humans.


The destruction of tropical forests is causing the rapid extinction of the natural species that are
native there.


Conservation is a necessary component of a solution to the biodiversity crisis.


The loss of species diversity is immensely significant because it also means a permanent loss of
genetic resources.


More than half of all the world's natural species have their home in the earth's tropical forests.


                                                         Pakenham, J. Making Connections, CUP, 1998



A Closer Look

1.    For what reason or reasons are the tropical forests being destroyed?

b.     to make land available for agriculture

c.     to provide places for people to live

d.     in response to the demand for hardwood

2.    How fast are tropical species now becoming extinct?

a.     at a rate similar to the rate that existed before the appearance of humans on the earth

b.     at a pace much faster than the rate that existed before the emergence of humans

c.     at a rate of exactly six thousand species per year

3.    In what way or ways does the writer justify the claim that wild species In tropical forests
are extremely valuable resources for humans?

a.     by illustrating their potential as domesticated species

b.     by illustrating their potential as suppliers of genetic material

c.     by illustrating their potential medicinal value

d.     by illustrating their potential role in maintaining the ecological balance of the forests

4.    Identify the examples in the passage that support your answer or answers to question 4.

5.    What factor or factors does the writer mention as contributing to the biodiversity crisis?

a.     sustainable economic development

b.     poverty

c.     overpopulation

d.    lack of appreciation of the value of biological resources





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