B17: Biodiversity and ecosystem

What is biodiversity?

What is biodiversity?

the variety of all the different species of organisms on Earth, or within an ecosystem

What is the advantage of high biodiversity?

ensures stability of ecosystems by reducing the dependence of one species on another

How are humans trying to maintain biodiversity?

breeding programmes • protection of rare habitats • reintroduction of hedgerows • reduction of deforestation and carbon dioxide emissions • recycling resources

Why are more resources being used, and more waste produced, by humans?

rapid growth in human population, and increase in the standard of living

Where does pollution occur?

water, air, and land

How are humans reducing the land available for other organisms?

building, quarrying, farming, and dumping waste

What are the negative impacts of the destruction of peat bogs?

reduces amount of available habitat, causing decreases in biodiversity • burning or decay of peat releases carbon dioxide into the atmosphere

Why have humans carried out large-scale deforestation in tropical areas?

• provide land for cattle and rice fields • grow crops for biofuels

What is food security?

having enough food to feed a population

What are the biological factors threatening human food security?

rapid population growth and increasing birth rate • new pests and pathogens • changing diets in developed countries • environmental changes • conflicts • costs of agricultural inputs

How can the efficiency of food production in farming be increased?

limit movement of animals • control temperature of surroundings • feed animals high-protein foods • give animals antibiotics • regularly use fertilisers, herbicides, and pesticides

What gases are increasing in atmospheric levels and contributing to global warming?

carbon dioxide and methane

How can fish stocks be maintained at a sustainable level?

controlling net sizes and introducing fishing quotas

How is biotechnology used to maintain the growing human population?

large quantities of microorganisms cultured for food, such as mycoprotein from Fusarium • GM bacteria producing treatments like human insulin • GM crops providing higher yields or improved nutritional values