GCSE Geography The Living World

What is an ecosystem?

A community of living organisms (plants and animals) interacting with each other and their non-living environment

What is a food chain?

A simple diagram showing the transfer of energy from one organism to the next (producer → primary consumer → secondary consumer)

What is a food web?

A network of interconnected food chains showing how energy flows through an ecosystem

What is a producer?

An organism that makes its own food by photosynthesis (usually plants)

What is a consumer?

An organism that gets its energy by eating other organisms

What is a decomposer?

An organism (e.g. bacteria or fungi) that breaks down dead material and returns nutrients to the soil

What is the nutrient cycle?

The continuous recycling of nutrients between living organisms and the non-living environment (soil, water, air)

Name the four main layers of a tropical rainforest

Emergent layer, canopy, under-canopy (understorey), and forest floor

Give three characteristics of a tropical rainforest climate

High temperatures all year (around 27°C), high rainfall (over 2000 mm per year), high humidity

How are plants adapted to the tropical rainforest?

Buttress roots for support, drip tips to shed water, large leaves to catch light, lianas and epiphytes to reach sunlight

How are animals adapted to the tropical rainforest?

Camouflage, living in the canopy, bright colours for warning or attracting mates, specialised diets

Name three causes of deforestation in tropical rainforests

Logging, cattle ranching, mining, road building, subsistence farming, commercial farming (palm oil, soya)

Name three impacts of deforestation

Loss of biodiversity, increased soil erosion, contribution to climate change (less CO₂ absorbed), disruption of the water cycle

What is sustainable management of rainforests?

Using the rainforest in a way that meets current needs without damaging it for future generations

Give three examples of sustainable rainforest management

Selective logging, replanting trees, ecotourism, international agreements (e.g. debt-for-nature swaps),

What is a hot desert?

An area that receives less than 250 mm of rainfall per year and has high temperatures during the day

Give three characteristics of a hot desert climate

Very low rainfall, high daytime temperatures, large temperature range between day and night, low humidity

How are plants adapted to hot deserts?

Deep or wide roots to find water, thick waxy cuticle to reduce water loss, spines instead of leaves, storing water in stems (cacti)

How are animals adapted to hot deserts?

Nocturnal to avoid heat, large ears to lose heat, ability to store water or get water from food, light-coloured fur/skin

Name three opportunities for development in hot deserts

Mineral extraction (oil, gas, metals), tourism, farming (with irrigation), renewable energy (solar)

Name three challenges of development in hot deserts

Extreme temperatures, lack of water, inaccessibility, soil erosion / desertification, conflict over resources

What is desertification?

The process by which fertile land becomes desert, usually due to climate change or human activities

Name three causes of desertification

Climate change (less rainfall), overgrazing, over-cultivation, deforestation, population growth

Name three ways to reduce desertification

Planting trees (afforestation), using drought-resistant crops, controlling grazing, building stone lines / terraces, water management

What is interdependence in an ecosystem?

When all living and non-living parts of an ecosystem depend on each other – if one part changes it affects the rest

Why are tropical rainforests important globally?

They absorb large amounts of CO₂, produce oxygen, contain huge biodiversity, and influence global weather patterns

What is biodiversity?

The variety of different species of plants and animals in an area

Why is biodiversity higher in tropical rainforests than in hot deserts?

Rainforests have a warm, wet climate that supports a wide range of species; deserts have extreme conditions that few species can survive