EDEXCEL (A) SALTERS-NUFFIELD BIOLOGY TOPIC 4 - BIODIVERSITY AND NATURAL RESOURCES

TOPIC 4 - BIODIVERSITY AND NATURAL RESOURCES

,
,4.1 KNOW THAT OVER TIME THE VARIETY OF LIFE HAS BECOME EXTENSIVE BUT IS NOW BEING
THREATENED BY HUMAN ACTIVITY

, HOW CAN VARIETY OF LIFE BE THREATENED BY HUMAN ACTIVITY?


THREAT EXAMPLE

Habitat loss Deforestation
Farming
Housing
Roads

Water pollution Sewage
Oil
Pesticides

Air pollution Acid rain
Carbon dioxide

Over exploitation Overfishing
Over farming
Hunting


4.2 i) UNDERSTAND THE TERMS BIODIVERSITY AND ENDEMISM


BIODIVERSITY WITHIN A SPECIES


KEY TERM DEFINITION EXAMPLE

Biodiversity Variety of life on earth.
It is the variety within and between all species of
plants, animals, fungi and microorganisms

Endemism Described the situation where a species is found Ring-tailed lemurs are only found
ONLY in one particular area in madagascar
THEREFORE…
Ring-tailed lemurs are ENDEMIC
to madagascar


Individuals within a species DIFFER from one another
- They show VARIATION (genetic variation)


Explain why GENETIC DIVERSITY is important in a species
- Allows a population to ADAPT
- To changing conditions
- Therefore maintaining the population


List the sources of genetic variation (link to topic 3)
- Mutations