Question

1.      Define and distinguish between biological extinction and mass extinction.

2.      Describe two economic and two ecological benefits of species diversity.

3.      What is the greatest threat to wildlife species?

4.      Explain why prevention is the best way to reduce threats from invasive species and list four proposed ways to implement this strategy?

5.      Summarize the roles of population growth, overconsumption, pollution, and climate change in the extinction of wildlife species.

Answer 1

1.

Biological Extinction refers to a species which is no longer found anywhere on earth e.g. Javan Tiger.

Whereas mass extinction refers to the extinction of a large number of species within a relatively short period of geological time due to factors such as a catastrophic global event or widespread environmental change that occurs too rapidly for most species to adapt.

2.

Two economic benefits of species diversity:

i) Agriculture products and

ii) fisheries products

Two ecological benefits of species diversity:

i) Greater species diversity ensures natural sustainability for all forms of life, and

ii) boosts ecosystem productivity where each species, no matter how small, all have an important role to play.

3.

The greatest threat to wildlife species is habitat destruction.

4.

An invasive species refers to a species that is not native to a specific location, and that has a tendency to spread to a degree believed to cause damage to the environment, human economy or human health. When an invasive species is introduced into an ecosystem, it may not have any natural predators or controls. It can breed and spread quickly, taking over an area. So prevention is the best way to reduce threats from invasive species.

There are three main methods used for control of invasive species: biological, mechanical, and chemical.

i) Biological control is the intentional manipulation of natural enemies by humans for the purpose of controlling pests.

ii) Mechanical control includes mowing, hoeing, cultivation, and hand pulling.

iii) Chemical control is the use of herbicides.