Environment Flashcards
What is a producer?
Produces its own food
Which direction do arrows point in a food chain?
Direction of the flow of energy, e.g. from producer to primary consumer
What are usually producers?
Plants and algae
What is a primary consumer?
Organisms that eats producers
What is a secondary consumer?
Eats primary consumers
What are herbivores, omnivores, and carnivores?
Herbivore – plant eater
Carnivore – meat eater
Omnivore – eats both plants and animals – can inhabit more than one trophic level
What are decomposers?
Microorganisms that that feed on dead animals, plants, and waste. Releases carbon and minerals back into atmosphere and soil
What is a trophic level?
The position of an organism in the food chain
Which type of pyramid is always pyramid shaped?
Biomass
Which type of organism is at the bottom of a pyramid of number or biomass?
Producer
How do you calculate efficiency between trophic levels?
efficiency = energy transferred to next level
————————————————— x100
total energy
energy transferred to next level/total energy x 100 = efficiency
What is biodiversity?
Variety of species in an ecosystem
What is an ecosystem?
A system that includes all living organisms (biotic) in an area and non-living (abiotic) factors
Advantages and disadvantages of intensive farming?
Advantage – increased yield
Disadvantage – chemical pollution – run off, animal welfare concerns, antibiotic resistance
What can be pollution and how is it harmful?
Pollution kills plants and animals which can reduce biodiversity
- In water, from sewage, fertiliser or toxic chemicals
- In air, from smoke and acidic gas
- On land, from landfill and from toxic chemicals
What is an indicator species?
An indicator species is an organism whose presence or absence is used by scientists to determine if an area is polluted.
e.g. Lichen on Trees, blood worms in waterways
Pollution also indicated by pH and oxygen levels.
What is bioaccumalation?
When heavy metals or pesticides, which cannot be broken down in animals tissues, are washed into soils and rivers and pass through food chains. These chemicals reach a toxic level in organisms.
When toxins build up in a food chain due to pesticides washing into soils and river and pass through food chains.
How does an algal bloom kill fish and stuff?
- Algae block light
- Plants on pond floor die
- Bacteria eat dead plant
- Bacteria use up all oxygen
- Fish are die
How do microorganisms cause decay?
Micro-organisms digest materials from their environment for life processes. These materials are returned to the environment either in waste products or when living things die and decay. When decay is prevented, fossil fuels form.
They digest materials from their environment for life processes
Materials return to the environment in waste products or when living things die and decay
If decay prevented, fossil fuels form
Describe the carbon cycle
Carbon is passed from the atmosphere, as carbon dioxide, to living things. It is then passed from one organism to the next in complex molecules, and returned to the atmosphere as carbon dioxide again.
- From atmosphere, carbon passed to living things as co2
- Then passed from one organism to the next in complex molecules
- Returns to the atmosphere as carbon dioxide again
Describe the nitrogen cycle
OK so basically:
- Nitrogen from air or decomposing dead stuff is turned into ammonia by bacteria
- This is turned into nitrates by bacteria
- Some of this is turned back into air nitrogen by denitrifying bacteria (cringe; we don’t want that)
- The rest, plants absorb nitrates through roots (wahey very cool)
- Becomes amino acids and protein and stuff
- Plants eaten by animals
- Waste from animals (urea) happens
- cycle continues when urea is turned into ammonia again
Nitrogen compounds found in cells include proteins. Nitrogen from the air is converted into soluble ions absorbed by plant roots by bacteria.
It forms part of nitrogen compounds in the plants, and is then passed from one organism to the next by eating. It is returned to the atmosphere as nitrogen gas by bacteria after organism dies.
Denitrifying bacteria – anaerobic – farmers try to prevent. Turns nitrates into nitrogen.
- Nitrogen from is air is converted into soluble ions
- They are absorbed by plant roots by bacteria
- Forms part of nitrogen compounds in the plants
- Passed from one organism to the next by eating
- Returns to the atmosphere as nitrogen gas by bacteria after organism dies
What non natural thing can put nitrogen into soil?
Fertilizers
Lightning is a natural way though
