Topic 2: Biodiversity

Question 1

BIODIVERSITY

• Biodiversity refers to the diversity of living things. It can be studied at a range of levels
• Ecological diversity- different habitats on the planet
• Maintaining the number and diversity of habitats prevents extinction by maintaining sources of food and shelter for all species
• Community diversity- many species in a community
• Ecosystems with greater species diversity have more extensive food webs and are more likely to survive changing conditions
• Genetic diversity- diversity of genes in a population
• Populations with greater genetic diversity continue to produce healthy and fertile offsprings, resist disease and change overtime in response to changing environmental conditions and selective pressures

Answer 1

WHAT IS BIODIVERSITY

• Every continent and habitat has unique life forms
• Concentrated In tropics

Question 2

THREATS TO BIODIVERSITY

• Human activities have caused new selective pressures which are leading to the extinction of many species. These include;
• Overall harvesting and hunting
• Habitat loss
• Pollution (land/water/air)
• Climate change
• Introduced species

Answer 2

OVERHARVESTING & HUNTING

• Dodos went extinct and their disappearance is directly related to human activity
• Evolved in a land that was isolated from predators
• Human contract acted as a new selective pressure that they could not evolve to survive

Question 3

HABITAT LOSS

• 3 main types of habitat loss are destruction, degradation and fragmentation
• Orangutans are increasingly isolated as their source of food and shelter decline

Answer 3

POLLUTION

• 3 types; water, air, land
• Effects food web
• Pesticides Can was I to water ways and kill fish, cause bioaccumulation/biomagnification
• Prey organisms take in toxins as they feed to plants. Predators then eat many prey organisms and accumulate poisons

Question 4

CLIMATE CHANGE

• Increase In CO2 in the atmosphere increases greenhouse effect which increases global temperatures
• Caused by humans overuse of fossil fuels and reduction of forest
• Increased temperatures are causing arctic ice to melt and polar bears are suffering

Answer 4

INTRODUCED SPECIES

- Foxes- Selective pressure; predation on many ground birds/mammals

Question 5

PROTECTING BIODIVERSITY

• Stop overharvesting
• sustainable yield
• hunting and fishing laws
• Protect habitat
• refuges, parks, preserves
• Endangered Species Act
• Restricts destruction of habitat
• Captive breeding program

Answer 5

ENDANGERED SPECIES

• Extinct
• Extinct in wild
• Critically endangered
• Endangered
• Vunerable
• Lower risk