Topic 9 - Ecosystems Flashcards
What is an individual
a single organism
what is a population
all organisms of one species in a habitat
what is a community
all the organisms of different species living in one habitat
whats an ecosystem
a community of organisms along with the abiotic conditions
What does interdependence mean
organisms depending on each other to survive like food and shelter to reproduce
what is mutualism and give an example
where both organism benefit eg) bees and plants
what is parasitism and give an example
dogs and flees where one organism benefits and the other is harmed
Name some abiotic factors
temperature
amount of water
light intensity
level of pollution
name some biotic factors
competition
predation
How can we study the distribution of small organisms
using a quadrat
then take mean total no.oragnsims/ total number of quadrats
-to find population - multiply mean by total area of habitat
How can you study the distribution of organisms along a gradient
using a belt transect then plotting a graph
Name some factors which mean that energy is lost down the food chain
lost as heat
not all gets eaten
faeces
How do you calculate efficiency in energy levels
energy transferred to next level
/ energy transferred at previous level
How do human activities affect biodiversity
- fertilisers can leach into water and cause eutrophication
- fish farming
- introducing non-indigenous species
How does fish farming reduce biodiversity
-food in nets produces large amounts of waste in water
- breeding ground for parasites
-predators attracted and get trapped in nets
-sometimes fish escape and cause problems for indigenous species
(sometimes fish are stored in tanks with low biodiversity as only one species is farmed and free from plants, predators and parasites)
How does introducing a non-indigenous species reduce biodiversity
- compete with indigenous species for food and if they out-compete can lead to native species to die out
- can bring new diseases into habitat
Name some ways we can conserve and maintain biodiverisity
- Reforestation- more variety of trees to increase biodiversity and provide food and shelter
- conservation schemes- protect habitats and species in safe areas and introducing captive breeding programmes and seed banks to distribute rare endangered plants
Name some benefits of maintaining biodiversity
name 4
- creates jobs
- protects human food supply
- minimal damage to food chains
- future medicines
- ecotourism
What is food security
having access to enough food that is safe and has a right balance of nutrition
How does increasing consumption of meat and fish affect food security
- overfishing can cause species to die out
- feeding fish crops that could be eaten by humans
- less biomass in a food chain
How are environmental changes caused by human activity affecting food security
- burning fossil fuels releases CO2 which is a greenhouse gas which leads to global warming
- climate change reduces crop yield so less food for humans
What does food sustainability mean
meeting the needs of todays population without affecting the ability of furture populations to meet their needs
How do new pests and pathogens affect food security
cause damage to crops and livestock
-introduce diseases that can wipe out whole populations of crops can be damaged reducing yield
What is reverse Osmosis
- a method of desalination to get rid of impurities from water
- net movement of water from a lower salt concentration to a higher salt concentration over a partially permeable membrane
