Topic 7 - Ecology Flashcards
Define habitat
the place where an organism lives
Define population
all the organisms of one species living within a habitat
Define biotic factors
living factors of the environment
Define abiotic factors
the non-living factors of the environment
Define interdependence
any change in the ecosystem can cause major change
Define community
the populations of all the different species living within a habitat
Define ecosystem
the abiotic and biotic parts of an environment, and how they interact with each other
Give some examples of abiotic factors
- wind intensity/direction
- carbon dioxide level
- oxygen level
- soil pH and mineral content
- light intensity
- temperature
- moisture level
- water
Give some examples of biotic factors
- new predators
- species outcompeting another
- new pathogens
- availability of food
Define interspecific competition
competition occurs between members of different species
Define intraspecific competiton
competition occurs between members of the same species
What are the 3 types of adaptation?
- structural - features of an organism’s body
- behavioural - the way that organisms behave
- functional - happens inside the body
Define an adaptation
feature/behaviour that helps an animal survive in its environment
Define an extremophiles
organisms (usually microorganisms) that can survive in very extreme environments
Name 2 important features of a predator-prey graph
- prey line reaches a higher peak than predator line
- predator line is offset to the right as it takes time for them to reproduce
Smaller organisms tend to reproduce _______ (think bacteria)
faster
Define a producer
they produce their own food using energy from the sun - the first stage of the food chain
Define a primary consumer
they eat the producers (usually insects)
Describe how you use a quadrat to work out the population of an organism in one area.
- place the quadrat on a random patch of grass in the area
- use a random number generator to decide how far to walk
- count how many organism are in the quadrat
- repeat this 15 times
- work out the average number of organisms per m²
- multiply this average by the area of the field
What is a belt transect used to study?
the distribution of an organism along a line
Describe how to use a belt transect
- place a tape across the area you want to study
- place the quadrat at intervals along the line
What are the 4 main processes in the water cycle?
- evaporation
- condensation
- precipitation
- transpiration
What are the processes called when water seeps into the ground?
- percolation
- stored in the water table
- returns back to sea through groundwater flow
Describe the carbon cycle
- carbon dioxide is removed from the atmosphere during photosynthesis for plants
- when plants respire, some carbon dioxide is returned to the atmosphere
- when plants are eaten by animals, the carbon becomes part of the fat/protein in their bodies
- when the animals respire, some carbon dioxide is returned to the atmosphere
- when plants die, animals eat their remains and respire so carbon is returned to the atmosphere
- combustion of wood/fossil fuels releases carbon dioxide into the air
In the atmosphere, carbon is stored as …
carbon dioxide
In animals, carbon is stored as ….
carbohydrates / fats / proteins
In fossil fuels / the ground, carbon is stored as …
hydrocarbons
What microorganisms carry out decay?
bacteria and fungi
What factors does decay need?
- warmth
- oxygen
- water
Describe how water affects rate of decay
microorganisms require water in order to live - the greater the moisture, the faster the rate of decay
Describe how oxygen affects the rate of decay
microorganisms require oxygen in order to live - they respire to release energy
Describe how temperature affects the rate of decay
- enzymes break down organic material
- as temperature increases, the rate of decay increases - enzymes are working at their optimum temp
- if it gets too hot, the enzymes will denature
What are the main gases that biogas contains?
- methane (most important one)
- carbon dioxide
How is biogas formed?
when bacteria break down plant/animal material anaerobically
What are the 2 main types of biogas generators?
- batch generators - make biogas in small batches
- continuous generators - make biogas all the time
Describe how you would investigate the effect of temperature on the rate of decay
- add 5cm³ of lipase solution to a test tube
- add 5cm³ of milk, 5 drops of phenolphthalein indicator and 7cm³ of sodium carbonate solution to another test tube (should turn pink)
- put both tubes into a water bath at 20 ℃ and leave them until they reach 20℃ (use a thermometer)
- add 1cm³ of lipase solution into the milk and start at stopwatch and stir
- once the solution goes back to white, stop the stopwatch
- repeat at different temperatures
Why does the solution change from pink to white in the rate of decay practical?
- the pH falls
- because lipase breaks down fats to produce fatty acids and (glycerol)
Why is a temperature sensor and data logger better than using a thermometer?
- more accurate
- gives continuous readings
- reduces human error
Define biodiversity
the variety of different species of organisms on Earth, or within an ecosystem
Describe how more waste can affect the water
- sewage and toxic chemicals can pollute water
- affects plants/animals that rely on the water
Describe how more waste can affect the land
- toxic chemicals are used for farming
- nuclear waste is buried underground
Describe how more waste can affect the air
- smoke and acidic acids can pollute the air
- e.g sulfur dioxide can cause acid rain
Describe global warming (what it is, main gases, effects)
- increasing levels of greenhouse gases trap the heat in - enhanced greenhouse effect
- main gases = methane and carbon dioxide
- effects = ice melts + sea levels rise, loss of biodiversity, changes in migration patterns
Describe the negative effects of deforestation
- humans want to use the land for other things (farming)
- less carbon dioxide is absorbed so carbon sink is reduced
- more carbon dioxide is added as the trees are burnt
- also leads to less biodiversity
Describe the destruction of peat bogs
- they’re drained so the area can be used as farmland or the peat is dried to use as fuel
- when peat is drained, it comes into contact with air and some microorganisms decompose it - they respire and release carbon dioxide (carbon sink is reduced)
- carbon dioxide is also released when peat is burned as a fuel
- also destroys habitats which reduces biodiversity
What are some ways to maintain biodiversity?
- breeding programmes to protect endangered species
- governments introduce regulations to reduce deforestation
- programmes to protect and regenerate rare habitats
Why can we not always maintain biodiversity?
- expensive
- may leave local people unemployed
- protecting biodiversity can affect development
- protecting biodiversity can lead to food scarcity - e.g pests are killed to protect crops
What is always at the bottom of pyramids of biomass?
producer
(trophic level 1)
Why is energy lost between each trophic level?
- not all material is consumed
- energy is used for respiration, movement, growth etc.
- faeces lost
- energy is lost as heat
% efficiency (biomass transfer) =
energy in tissues / energy in food x 100
What are some factors affecting food security?
- climate change + global warming
- population growth
- changing diets - produce is now shipped around the world
- war
- costs of farming
- new diseases can destroy crops/livestock
Why is it more energy efficient to eat crops rather than animals?
the food chain is shorter so less energy is lost
Why is intensive farming more energy efficient?
- less energy is being used for movement and heat retention so they can use more energy for growth
- farmers can keep more animals in a smaller space
Define food security
having enough food to feed a population
What are the negatives to intensive farming?
- disease can spread easily between animals
- cruel to the animals
What are two ways to improve fish stocks?
- fishing quotas (limits to the number/size of fish you can catch)
- net size (bigger mesh size will let the smaller, unwanted fish escape)
Describe how to make mycroprotein
- clean the fermenter
- add sugar syrup and fusarium fungus
- allow to grow
- harvest, purify and dry
- add flavourings and colour
What does the Fusarium fungus feed on?
sugar syrup
Give the advantages of using mycoprotein as a food
source instead of traditional meat sources.
- needs less land
- cheap to mass produce
- lots of protein, little fat
- energy efficient
Describe the features of an industrial fermenter
- water jacket - maintains the correct temp
- data logger - monitor pH and temp
- stirrer - mix everything evenly
- oxygen supply - for aerobic respiration
Name a genetically modified organism which has been used to help humans
insulin
