BiologyY9 Flashcards
Name some decomposers
maggots, protists, starfish, earthworms, nematode worm, mushroom, toadstool
What does decay return to the soil?
carbon & nitrogen
Why is decay important?
Recycling of nutrients in ecosystem
The nitrogen cycle. Why is it important?
Nitrogen is needed to make protein. Protein is needed for growth
Air is 80% nitrogen. What forms do organisms use nitrogen?
Take it from nitrates in the soil.
What is nitrogen fixation and which organism carries this process out?
Nitrogen-fixing bacteria
What are the four methods for nitrates to enter the soil?
- Lightning & rain; 2. nitrogen-fixing bacteria 3. decomposers = ammonia via nitrifying bacteria 4. Artificial fertilisers
What natural phenomenon converts nitrogen into the form organisms can use?
Lightning & rain
Carbon cycle - name three things which release carbon
Volcanism, deforestation, agriculture, resource extraction, burning of fossil fuels. Fire, greenhouse gases, erosion.
Carbon cycle - name three things which capture carbon
The ocean captures CO2; productivity & biomass (growing stuff)/photosynthesis; Soil & sedimentation;
Water cycle - name the four stages
- Evaporate 2. Condense (clouds) 3. Precipitation 4. Absorption & runoff
Food security - what is the definition?
Access to safe and healthy food & all times.
How can food security be improved?
Fertilisers; different breeds; more productive varieties
What food security problems are there?
Rising population, climate change, warfare; biofuels and renewables on agricultural land
Why can food security be difficult to achieve in poor countries?
No money to invest
How can increasing population cause problems?
More mouths to feed - enough food and water????
What is conservation?
prevention of wasteful use of a resource; protecting environment or biodiversity.
Give some examples of conservation
Preservation; protecting species; stopping extinction; reducing population decline; excluding human use of an area for the benefit of nature; protecting habitat; rewilding; switching to renewables; reducing uses of plastic
Give some examples of protective designations
SSSI - Sites of Special Scientific Interest; RAMSAR - European protected sites; National Parks; Green Belt
Biodiversity - what is it?
Organisms and wildlife in an ecosystem
Why does biodiversity matter?
The whole ecosystem is linked and in balance - affected as a whole by damage. Eg overfishing reduces the breeding populations and removes species from the food chain which causes other species to suffer. Fish farming = one type of species (monoculture) instead of a mixed species balance; diseases.
Trophic levels & energy & 7 life processes. What are the 7?
Movement, respiration, growth, reproduction, excretion, nutrition, sensitivity
Interdepedence of species. Give an example of mutualistic relationship
Tick birds eat insects/parasites on rhinos;
Give an example of a parasitic relationship
Flea on cat and dog
What does an ecosystem consist of?
Organisms - different forms e.g plants take in sunlight; primary & secondary consumer. Contains organisms that are adapted to living in that ecoystem. Live off each other and have multiple food chains
What are the different levels in ecosystem?
1 individual plant or animal; POPULATION is all the animals in one species living together and can breed; COMMUNITY - all the organisms that live in and potentially interact in an ecosystem; ECOSYSTEM - all the animals and the environment they live in
What might animals compete for?
Food, space, water, mates
What might plants compete for?
Sunlight, space, water, minerals, pollinators
Into which form do decomposers convert protein from decaying organisms?
Ammonium NH4
How do nitrogen containing compounds pass from top consumers?
Assimilation
Which organisms convert nitrates in the soil to nitrogen in the atmosphere?
Denitrifying bacteria
What is the carbon cycle?
The geochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, atmosphere.
Name five things which cause carbon release into the atmosphere?
volcanism, deforestation/reforestation, agriculture, burning of fossil fuels, resource extraction
Name three geographical things which release carbon?
weathering, respiration, photosynthesis (terrestrial & marine)
