20 1 human impact biodiversity pollution and conservation

Food production has been increased using:

Monoculture is the practice of growing a single crop species on an area of land.

Advantages of crop monocultures include:

False. Monocultures can harm wildlife as they lead to reduced biodiversity.

Disadvantages of monocultures include:

Intensive farming is a method of farming that aims to maximise production within a limited land area. An example is the raising of livestock in confined spaces.

False. ** Limiting livestock movement increases food production efficiency by reducing energy used for movement**; this energy can instead be used to fuel growth.

Drawbacks of keeping livestock in confined spaces include:

Biodiversity is the number of different species found in a habitat.

Humans cause habitat destruction by:

True. Human activities can remove species from food chains, disrupting food webs and having harmful effects on habitats.

Harmful effects of deforestation include:

Human activities that result in water pollution are:

Consequences of untreated sewage runoff into water systems include:

Eutrophication is the process by which increased nutrient availability in a body of water leads to a decrease in dissolved oxygen levels.

The process of eutrophication is as follows:

Plastic pollution can affect the environment as follows:

Carbon dioxide is released by human activities such as:

True. Methane traps more radiation per molecule than carbon dioxide, so is a powerful greenhouse gas.

Human activities that increase atmospheric methane are:

Methane and carbon dioxide are greenhouse gases, so their release causes an enhanced greenhouse effect, leading to climate change.

A sustainable resource is one that can be produced as rapidly as it is harvested; this means that it will not run out.

Examples of resources that can be managed sustainably include:

Forests can be conserved as follows:

Fish stocks can be conserved as follows:

Endangered species are plants or animals at risk of extinction.

Factors that contribute to species becoming endangered include:

Conservation methods include:

Breeding programmes can be used to increase the reproductive success of endangered species in captivity; this can help to increase their population size and genetic diversity.

False. A seed bank is a collection of seeds from many plant species.

Conservation is importance because it:

Ecosystem functions are the natural ecosystem processes and features that benefit humans, e.g.

True. Artificial insemination and IVF are important processes in captive breeding programmes.

Maintaining population size is important because a large population is more likely to be genetically diverse. Genetically diverse populations are more likely to be able to respond to change and so are less likely to go extinct.