Human Impact: Biodiversity, Pollution & Conservation (Cambridge (CIE) IGCSE Co-ordinated Sciences (Double Award): Biology): Flashcards

A unit containing the community of organisms and their environment, interacting together.

The number of different species in an area.

Human pressures that threaten other species include:

• habitat destruction (e.g. for farming or building)

• pollution

• hunting and overharvesting

• introduction of new (invasive) species

The undesirable effects of deforestation include:

• loss of habitat and reduced biodiversity, which can lead to extinction of species

• increased carbon dioxide in the atmosphere, as fewer trees remove it by photosynthesis and burning timber releases it

• soil erosion, as roots no longer bind the soil

• flooding, as less water is absorbed and soil is washed away

biodiversity

biodiversity

Habitats are destroyed to make space for human activities, including:

• clearing land for farming (e.g. crops or grazing cattle)

• building to house a growing human population

• pollution from human economic activities

True.

With fewer trees, less carbon dioxide is removed by photosynthesis, and burning the felled timber releases even more carbon dioxide.

A species that is at risk of becoming extinct.

Protected areas (e.g. national parks and reserves).

Captive breeding programmes in zoos.

Seed banks.

Laws to protect species and their habitats.

Education.