Biology #4 Ecology

  • Created by: MBid89
  • Created on: 07-04-18 15:09
Define species
A group of organisms that can interbreed to produce fertile offspring
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Define population
A group of organisms of the same species living in the same area at the same time
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What are autotrophs?
'self-feeding' organisms: absorb CO2, water, nutrients & light to synthesise all the carbon compounds needed.
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What are heterotrophs?
'other-source feeding' organisms: obtain carbon compounds from other organisms. Compounds including proteins & starch must be digested before they can be absorbed & used.
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Name 1 type of unusual plant that is NOT autotrophic
Ghost orchids (feed on fungi on trees)
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What are saprotrophs and how do they source their food/ nutrients?
Bacteria, fungi. They live in or on non-living organic matter (i.e. dead leaves, wood, dead animals), secreting digestive enzymes into it & absorbing digested products. They therefore 'recycle' nutrients.
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What are consumers and how do they source their food/ nutrients?
Deer, vultures, humans etc. They inject organic matter i.e. recently killed or living.
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What are detrivores and how do they source their food/ nutrients?
Earthworms, woodlice, larvae. They ingest non-living organic matter (dead material from living organisms is called 'detritus'; i.e. dead leaves, roots, decomposing animals, faeces)
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Define community
a group of populations living & interacting with each other in an area
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What is a food web?
the complex network of feeding relationships in a community
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Define ecosystem
a community & its abiotic (non-living) environment
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What is a mesocosm?
A small, closed-off experimental system set up as an ecological experiment
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What are the 3 requirements for a sustainable eco-system?
1. nutrient availability 2. detoxification of waste 3. energy availability (i.e. the sun)
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Suggest how quadrant sampling could be used to estimate population sizes within a given area (aka. method)
Mark out grid lines of/ around an area. Randomly generate co-ordinates & place quadrat. Record presence/ absence of species of interest inside area. Repeat
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What is the aim of using a chi-squared test (in ecology)?
To find the association between 2 species whose presence/ absence has been recorded (e.g.) in a large number of quadrats
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What does a food chain show?
The flow of energy through the trophic levels of a feeding relationship
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What type of organisms are producers? (3)
Plants, algae & some bacteria
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How is energy used/ converted by producers?
light energy --> [via photosynthesis] --> carbon compounds containing chemical energy
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In what 4 ways is energy lost in ecosystems?
1. some organic matter (i.e. hair, bones) not eaten by consumers [faeces] 2. some parts of organisms are indigestible (i.e. cellulose) [faeces] 3. some organisms die before they are eaten 4. cell respiration
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What is a trophic level?
The position of an organism in the food chain
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Compare how light and nutrients are used in ecosystems
Light is converted into chemical energy, used in the cell and lost as heat. It cannot be recycled. There is a limited supply of nutrients, however they can be recycled by decomposers (detrivores & saprotrophs)
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What is a 'sink' in the carbon cycle and what is a 'flux'? Give examples of each
sink= storage/reservoir of CO2 (e.g. diffusion in air/ water, contained in producers/ consumers/ saprotrophs.. while they are alive). flux= transfer of carbon/ methane (e.g. via photosynthesis, cell resp., feeding, death, combustion)
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By which organism is methane naturally produced as a waste product? (hint: prokaryotes, not cows)
Prokaryotes called 'methanogenic archaeans' that live in anaerobic conditions (swamps/ bogs) where saprotrophs cannot break down organic matter
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Carbon dioxide can be found in 2 forms in water/ aquatic environments. What are they?
1. dissolved 2. hydrogen carbonate ions. Both are used by aquatic autotrophs in photosynthesis
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What is the main component of limestone?
calcium carbonate (CaCO3)
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What happens when acid rain reacts with limestone?
Carbon (which was locked up before in limestone/ fossils/ coral reef) is released in the form of hydrogen carbonate ions
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How is coal formed?
Peat (formed in bogs/ swamps of partially decomposed plant matter) is crushed & converted into coal
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How are oil & gas formed?
Silt + dead marine organisms deposited on marine beds. Turns into shale. Organic matter (aka dead marine organisms) trapped in rock pores turn into oil/ gas.
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How does the greenhouse effect happen?
75% of solar radiation reaches Earth's surface (the rest is absorbed in the atmosphere). This is short wavelength. Earth re-emits as long wavelength (mostly infrared aka heat). 70-85% trapped by greenhouse gases & passes back to Earth causing warming
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List 4 greenhouse gases
Most signifiant: CO2, water vapour. Methane, nitrous oxides, halocarbons (produced by industry).
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What are the dangers of increased CO2 on marine life?
CO2 dissolves into ocean, causing ocean acidification. Increasing CO2 levels means that organisms such as coral cannot access the carbonate ions they need as part of their calcium carbonate skeletons.
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Other cards in this set

Card 2


Define population


A group of organisms of the same species living in the same area at the same time

Card 3


What are autotrophs?


Preview of the front of card 3

Card 4


What are heterotrophs?


Preview of the front of card 4

Card 5


Name 1 type of unusual plant that is NOT autotrophic


Preview of the front of card 5
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