Threats to Biodiversity 3.8

Question 1

What is exploitation?

Answer 1

Humans exploit many natural resources for food and raw materials. To exploit a resource means it is harvested to make the best use of it.

Question 2

What is overexploitatiom?

Answer 2

When resources are exploited at a rate that cannot be sustained.

Question 3

What can be done to avoid over exploitation?

Answer 3

There must be enough species members remaining to reproduce and continue the species.

Question 4

When small populations of a species remain, genetic diversity tends to be ____

Answer 4

Low

Question 5

Loss of diversity can be critical and lead to inbreeding which results in…

Answer 5

Poor reproductive rates and lack of diversity which limits the ability to respond to environmental change.

Question 6

The bottleneck effect is..

Answer 6

When remaining organisms may be descendants of only a small number of individuals and therefor lack genetic information

Question 7

Can some species have a naturally low genetic diversity and yet remain viable?

Answer 7

Yes

Question 8

What is fragmentation?

Answer 8

One larger habitat is divided to form several smaller habitats (due to agriculture, roads or urbanisation)

Question 9

More isolated fragments and smaller fragments exhibit a _____ species diversity

Answer 9

Lower

Question 10

What are fragmented habitats prone to do?

Answer 10

Degrade at their edges

Question 11

What increases between species in fragments ?

Answer 11

Competition

Question 12

What is a habitat corridors purpose?

Answer 12

Allows the movement of animals between fragments, increasing access to food and choice of mate. Leading to possible recolonisation after local extinction

Question 13

What is an Introduced species?

Answer 13

A species that humans have moved either intentionally r accidentally to new geographic locations

Question 14

What is a Naturalised Species?

Answer 14

An introduced species that has become established within wild communities.

Question 15

What is an invasive species?

Answer 15

A naturalised species that spreads rapidly and eliminates native species (therefore reducing species diversity)

Question 16

How do invasive species have a negative impact on the environment (other than reducing diversity)

Answer 16

They are likely to be free of the predators, parasites, pathogens and competitors that limit population size in their native habitat. They may also prey on native species, out-compete them for resources or hybridise with them.