B18- Biodiversity and ecosystems Flashcards
Biodiversity def?
Why is it important?
The variety of different species on Earth or in an ecosystem
Ensures stability of an ecosystem by reducing the dependency on one species for food/shelter
2 reasons the population has grown so rapidly
-Healthcare preventing diseases
-Growth of food
Deforestation
Why?
Impact?
-Make space for housing, agriculture, quarries and use timber for fuel
-Loss of habitats, lower biodiversity, lower intake of CO2
Increased waste
Why?
Impact?
-Increased population, more packaging, more industrial waste from factories
-Air pollution, water pollution
Burning fossil fuels
Why?
Impact?
-Generate electricity
-Being used faster than it can be made
Peat bog destruction
Why?
Impact?
-Burnt as fuel, in garden compost
-Being destroyed faster than its made, loss of habitats and biodiversity
-Releases carbon dioxide into atmosphere
3 causes of land pollution and why are they bad?
Industrial waste- toxic chemicals from factories disposal
Herbicides/ pesticides- toxic chemicals from farming
Household waste- landfill, takes up space, destroys habitats
1 cause of air pollution, why is it bad?
Burning fossil fuels- produces smog and acid rain
3 causes of water pollution and why are they bad?
Fertilisers in farming, cause eutrophication
Toxic chemicals- from landfill sites, wash into rivers
Untreated sewage- can be pumped into rivers
Key reason why pollution is bad?
Can kill organisms and reduce biodiversity
2 impurities released from fossil fuels and what do they cause?
Sulfur dioxide- breathing problems, acid rain
Nitrous oxide- acid rain
2 Effects of acid rain
-Destroy roots of plants due to lower pH
-Kill leaves of plants from rain
Effect of smoke pollution on environment and humans?
-Dimming effect, could cool the Earth temp
-Damage lungs
What is smog?
A haze of small particles that can be seen in the air over cities
2 ways to monitor pollution
-pH and oxygen measuring instruments
-Bioindicators, species that are only found in certain pH/oxygen levels
3 examples of seasonal changes to an environment
Hours of daylight
Amount of rainfall
Temperature
3 examples of geographical changes to an environment
Availability of water
Water salt content
Variation in soil pH
3 positive & 3 negative examples of human activity changing an environment
Positive: Replanting hedgerows, Conservation measures, Reducing water pollution
Negatives: Pollution from agriculture, Acid rain affecting soil, Climate change
4 biological consequences of global warming?
-Loss of habitat- rising sea levels cause flooding
-Change in distribution- changes in temp and rain
-Changes in migration- due to changing seasons
-Reduced biodiversity- extinction
2 main greenhouse gases
Carbon dioxide
Methane
How do greenhouse gases cause global warming?
Short wavelength radiation from the sun enters the atmosphere and is absorbed by the Earth. Some are re-emitted as longer wavelength radiation into space, but some are absorbed by greenhouse gases in atmosphere. The temp will increase, causing global warming.
5 ways humans are reducing the negative effects on biodiversity
Breeding programmes for endangered species
Protection of rare habitats
Replanting hedgerows
Reduction of deforestation
Recycling resources
Bioaccumulation explanation?
Toxins enter food chain, hard to break down, build up at each stage, dangerous level of toxins in top predators
Eutrophication detailed description
Nitrates and minerals stimulate growth of algae. Creates high competition for light, other plants can’t photosynthesise and die. Increase in microbes to feed on dead plants. Microbes use oxygen to respire. Less oxygen for other organisms, they then die. More microbial respiration. Eventually oxygen levels drop greatly, all aerobic organisms die and the pond is ‘dead’.
Trophic levels def?
Positions of organisms within a food chain
Trophic levels from 1-4 and their meaning?
- Producers, make their own food by photosynthesis
- Primary consumers, herbivores
- Secondary consumers, carnivores
- Tertiary consumers, carnivores
Apex predator def?
Decomposers def?
Carnivores at the top of the food chain with no predators
Organisms that break down dead matter into useful nutrients in the soil
Biomass def?
The mass of material in living organisms
What does a pyramid of biomass look like?
Key features?
Producers are always at the bottom
The amount of biomass is always less than the previous stage
3 reasons why the biomass decreases with each trophic level
-Some used in excretion e.g urea
-Some is used in respiration
-Non-eaten parts e.g bones
Incident energy def?
How much incident energy is used by plants?
How much biomass is transferred between each trophic?
The light falling on Earth
1% of incident energy is used by algae and plants for photosynthesis
10% of biomass from a trophic level is transferred to the level above
Food security def?
Having enough food to feed a population
6 biological factors that are affecting food security
-Increasing birth rates
-Changing diets in developed countries, local food transported away from people who need it
-New pests and pathogens in farming
-Environmental changes, flooding/droughts
-Cost of agricultural inputs, seed, fertilisers
-Conflicts
3 ways to create sustainable food production
-Maintaining soil quality
-Finding more efficient methods
-Taking care of fish stocks
How can growth in livestock be increased?
Why can this be bad?
By feeding the livestock a high-protein diet
It adds an extra step to the food chain so less biomass and food is at the end of the chain
2 ways to improve the efficiency of food production
-Limiting the movement of animals to reduce respiration
-Controlling the temperature to reduce respiration, less energy transfer to the environment, more biomass for growth
Why are fish stocks concerning?
Fish stocks in the ocean are declining, if breeding can’t take place then a species may disappear
2 ways to help maintain fish stocks and what do they mean?
Controlling net size, allow baby fish to escape and later breed
Quotas, allowed number of fish to catch
Why is modern biotechnology helpful?
It allows large quantities of microorganisms to be cultured for food
What could genetically modified bacteria be used to produce?
What could genetically modified crops be used to provide?
Drugs such as insulin on an industrial scale, helps people with diabetes
More food/ food with improved nutritional value e.g golden rice
Name of the new protein-rich food developed recently?
Made from?
How is it created?
Why is it good?
Mycoprotein
Fusarium fungus which grows on glucose syrup
Grown in aerobic conditions, then harvested and purified
Cheap ingredients, reproduces rapidly
