Ecology Flashcards
Ecosystem
The interaction of a community with the non-living parts of their ecosystem
Community
All the organisms that live in a habitat
Habitat
The place where an organism lives
Interdependence
How different species rely on each other for survival
Name abiotic factors affecting organisms in an ecosystem [7]
- Light intensity (light meter)
- Temperature (thermometer)
- Soil pH and mineral ions (Chemical analysis)
- Carbon dioxide levels (gas analysis)
- Oxygen levels (oxygen electrode)
- Moisture levels
- Wind levels
Name biotic factors affecting organisms in an ecosystem [4]
- Availability of food
- New predators
- New diseases (pathogens)
- Interspecific competition (between species)
What are the 3 different levels of organisation in an ecosystem?
- Individual organisms
- Populations- groups of individuals in the same species
- Communities- many populations together
What is the purpose of using quadrats?
Quadrants are used to estimate the size of a population or the distribution of organisms in a habitat
What are the 2 types of methods involving quadrats?
- Random sampling
2. Transect sampling
How can we compare the distribution of the same organisms in different habitats? [4]
[Random sampling]
- Choose the sample area at random
- Use a random generator to place the quadrat in a given habitat
- Take several random readings
- Calculate the mean number of organisms
How can we measure the effect of an abiotic factor on the distribution of organisms? [4]
[Transect Sampling]
- Use a tape measure to produce a transect
- Place quadrat
- Score the amount of species present
- Place the quadrat at regular intervals along the transect
- Repeat several times (improves reliability)
- Carry out at different places
What do animals compete for? [3]
- Food
- Territory
- Mates
What do plants compete for?
- Light
- Mineral ions
- Water
- Space
What is an extremophile?
Microorganisms that survive and reproduce in extreme conditions
How are microorganisms that live at high or low temperatures adapt?
Adapted enzymes=> do not denature
How are microorganisms that live in very salty environments adapt?
Cytoplasm adapted=> water does not move out of cell
What are the 3 different types of adaptations to organisms?
- Structural- shape/colour
- Behavioural-migration
- Functional- reproduction/ metabolism
What is the effect of a Small SA:V ratio?
Less thermal energy is transferred to the surroundings
What is the effect of thick fur?
Traps a layer of air, which acts as an insulating layer, stopping transfer of thermal energy
What is the effect of small ears?
Reduces surfact area for thermal energy transfer
What is the effect of white colour?
Camouflage in the snow=> Prey do not see them=> more food
What is the effect of large feet?
Spreads weight over snow increasing run speed
What is the effect of winter hibernation?
Energy stores are conserved
Why does a Camel have a hump?
Fat can be stored and metabolised for energy
Why does a camel have thick lips?
Eat prickly desert plants without feeling pain
Name a functional adaptation of a camel
Kidneys produce concentrated urine (less water)
Name a behavioural adaptation of a camel
Most active in early morning or late evening
Why do camels have a large SA:V ration and large ears?
Transfers energy quicker to surroundings=> cooling them down
Why do desert plants have a small surface area for leaves?
Traps a layer of moist air=> reduces water loss by evaporation=> more for photosynthesis
Why do desert plants have sharp spikes?
Discourage animals eating them
Why is the stem of cacti thick?
Store water in tissues=> photosynthesis
How does decay occur? [5]
- Microorganisms such as bacteria / fungi
- Feed on dead organisms and break them down (decompose) them into simpler substances
- They need oxygen because they carry out aerobic respiration
- Release carbon dioxide and mineral ions
=> THEY ALSO RELEASE HEAT ENERGY
=>Some of the nutrients are used for growth and they reproduce
5. Carbon, hydrogen, oxygen and nitrogen are returned back to the environment and recycled back to provide the building blocks for future organisms
Water cycle
Describes how fresh water circulates between living organisms, rivers and the sea
Carbon cycle
Describes how carbon is recycled in nature
Describe the role of photosynthesis in the carbon cycle [4]
- Plants photosynthesise
- Take in Carbon Dioxide
- Produce Carbs, proteins and fats
- Animals eat green plants or other animals passing on carbon
Describe the role of Respiration in the carbon cycle [7]
- Animals and plants respire
- Release Carbon Dioxide
- Plants and animals die
- microorganisms carry out decay
- Break down waste
- Microorganisms respire
- release carbon dioxide
Describe the levels of a food chain [4]
- Producers=>
- Herbivore/primary consumer=>
- Carnivore/ secondary consumer
- Larger carnivore/ Tertiary consumer
What is each of these feeding levels called?
A trophic level
What is another name for the top consumer?
Apex predator
Describe a feeding relationship on a Predator-prey graph [7]
- More food, prey grow and reproduce successfully
- Larger population of prey
- More food for predators
- Predator numbers increase
- Prey begin to fall
- Less food for predators
- Predators
Biodiversity
The variety of al the different species of organisms
What is compost? [3]
- Decomposers break down waste
- Make a brown crumbly substance called compost
- Contains nutrients=> can be used as a fertiliser
How can compost be used in a biogas generator? [4]
- If bacteria decompose anaerobically produce methane gas.
- Plant or animal waste is placed in biogas generator, which produces methane (need warm temperatures of 30)
- Used as fuel In cooking, electricity and heating and in car fuel
- Renewable energy supply
What are the advantages of biogas generators? [3]
- Reduced fossil fuels and non renewable fuels
- Less sulphur dioxide/smoke
- Fertiliser to help crop growth
- cheaper in long term
What are the disadvantages of biogas generators? [3]
- High initial cost
- Explosion risk
- Technical knowledge or training needed
What are the factors affecting biodiversity? [3]
- Availability of water
- Temperature
- Atmospheric gases
What are the 3 different ways land pollution is formed?
- Household waste-
[toxic chemicals=> soil, landfill=> destroys habitat] - Industrial waste-
[toxic chemicals, e.g. Chernobyl] - Farming-
[insecticides=> poisonous=> washed into rivers and sea=> bioaccumulation]
= Organisms can carry toxins throughout the food chain, toxins can build up and cause death.
Bioaccumulation
Small amounts of substances passed throughout the food chain and accumulates in a predator
Why does Bioaccumulation mostly affect animals at the end of the food chain?
Predators eat large numbers of prey that have ingested a substance
The level of toxicity is therefore much larger in these predators
Describe how eutrophication causes the death of the ecosystem [6]
- Fertilisers are washed into rivers and lakes = increase in nitrate or phosphate in the water
- algae growth in size => prevents sunlight reaching other water plants, which then die.
- Bacteriabreak down the dead plants and use up the oxygen in the water (decomposition)
- Microorganisms multiply rapidly => uses up all the oxygen = Oxygen level fall- fish die
- Fish decompose- microorganisms continue to use oxygen
- Lake may be left completely lifeless
Describe how acid rain is formed [5]
- Fossil fuels=> carbon dioxide
- Contains sulphur impurities
- Reacts with oxygen=> sulphur dioxide
- Breathing problems
- Sulphur dioxide and nitrogen dioxide dissolve in rainwater=> dilate sulphuric and nitrate acid
This is acid rain
What are the effects of acid rain?
- Falls onto trees- kills leaves, buds, flowers and fruit
- Soaks in soil- destroys roots
- If conc high=> kills animals and plants
How can acid rain be reduced? [4]
- Catalytic converters are fitted into exhaust to remove pollutant gases
- Low sulphur fuels have been introduced
- Electricity is generated from nuclear power
- Systems placed in power station chimneys- clean gasses before released into atmosphere
Explain how smoke pollution leads to cooler temperatures [5]
- Increased particulates in air
- Reflect sunlight
- Less on surface of earth
- Causes dimming effect
- Leads to cooling temperature
Smog
A haze of small particles and acidic gases that can be seen in the air
What are the main reasons for deforestation? [3]
- To grow staple foods, e.g. rice=> cheap food in developed world
- Cattle rearing=> beef market
- To grow crops for biofuels based on ethanol=> sugarcane and maize
What are the effects of deforestation? [3]
- Lose carbon dioxide sink
- Reduces biodiversity
- Causes increase in carbon dioxide through burning or decay => increases temp => global warming
- reduces rate at which carbon dioxide is removed
What is peat?
Plants that have partially decomposed after thousands of years
What can peat be used for? [2]
- Fuel
2. Mixed with soil to improve conditions
What happens when peat is extracted? [3]
- Contains locked away carbon
- Decomposes with microorganisms in presence of oxygen
- Releases carbon dioxide
How can we overcome the issue of using peat?
Using peat free compost => reduces demand of peat
How is methane gas released into the atmosphere? [2]
- Land used to grow rice- rice releases methane as it grows
2. Cattle release methane as they digest grass
Describe the greenhouse effect? [6]
- Infrared radiation from sun
- Passes atmosphere to earth
- Earth surface radiates different wavelength
- radiation (heat) absorbed by greenhouse gasses
- Trapped in earths atmosphere
- Earth increases In heat = global warming
What are the effects of global warming on the environment? [3]
- Rise in sea levels=> …
- Increased/ decreased rainfall=> …
- Extreme weather=> storms/ droughts-> …
How can we maintain Biodiversity? [5]
- Breeding programmes for endangered species (zoos)
- Protecting and regeneration of rare habitats
- Farmers keep margins and hedgerows
- reducing deforestation
- Recycling plastics rather than landfill
Biomass
The dry mass of material in an animal or plant
How much energy is passed on to the next trophic level after feeding?
10%
Why is energy reduced at each trophic level?/ Biomass loss [4]
- Respiration
- Heat loss
- Movement
- Faeces/urine
What is food security?
Having enough food to feed a population
- Ability to access food by growing or buying
- Awareness of need for a healthy balanced diet
What are factors affecting food security? [6]
- Increase in birth rate
- Changing diets in developed countries
- Conflicts affecting access to food/water
- new pest and pathogen
- environmental changes
- cost of agricultural inputs
How can we increase food security? [3]
- Maintaining or improving
soil quality - Efficient ways to produce food (selective breeding/GM tech)
- Managing fish stocks
- educating populations
Why is having a shorter food chain more efficient?
- Efficiency of food production would be greatly increased
- As plant biomass would be used to produce human biomass DIRECTLY
What are the conditions of food in factor farming? [4]
- Cramped conditions- calf crates, fish tanks, etc
- Controlled temperature
- Controlled feeding/ growth hormones. etc
- Controlled lighting
- Treated with prophylactic antibiotics
What are the 3 features of Intensive farming methods?
- Movement restriction
- Temperature control
- Large availability of food
Why is there movement restriction in intensive farming methods?
- Less energy lost for movement
- Reduces need for respiration
- Weight gain
- more biomass available from their food for growth
Why is the Temperature controlled in intensive farming methods?
- Heat conserved
- Less energy lost in controlling body temperature
- more biomass for growth
Why is there a large availability of food in intensive farming methods?
- More food available= fed more often
2. More energy for growth/ more food converted to biomass
What are the disadvantages of intensive farming?
- Easy spread of disease
- restricted movement/ overcrowding
- stress, cruelty. unethical
What are the advantages of Intensive farming?
- greater food production= cheaper food
- faster growth= more profit
- less energy lost through movement and keeping warm
What are the 2 ways to conserve fish stocks?
- Controlling net sizes=> big fish caught, young escape, grow and breed
- Fishing quotas=> limits catching, leaving population to breed = population increase
- Bans on fishing in breeding season/ in certain areas
How is Mycoprotein formed? [7]
- Fungus grows and reproduces rapidly on cheap glucose syrup
- In large containers called fermenters
- Requires aerobic conditions
- Mycoprotein harvested/ purified
- Dried
- Ammonia added as source of nitrogen
- pale yellow solid => shaped and flavoured
What are the advantages of getting more food from Mycoprotein? [4]
- Quicker production
- Suitable for vegetarians
- Cheaper
- Shorter food chain=> less energy lost
conditions of decay
- temperature
=work best in warm conditions, if temp too high enzymes denature, if too low = slow rate - moisture
=grow fastest in moist conditions => easier to digest food and prevents from drying out - oxygen
=mainly respire anaerobically => transfer energy, grow and reproduce
=decay more rapid in presence of oxygen
problem using peat
- peat = non renewable
- reduces biodiversity
- release co2
factory faming/biomass (must use points)
- More or less stages in a food chain
- More or less energy is lost through faeces, urine, movement, maintain body temperature at each stage
- More or less biomass lost
- More or less efficient
- More or less food produced
effect of rise in sea level
- Lead to flooding
- Damage habitat (food shortage)
- Organisms may not be able to survive and become extinct
- Reduce biodiversity
- Increase salt in soil will effect organisms.
effect of increased or decreased rainfall
Some animals may adapt as conditions may be favorable whereas others will disappear completely from an area
effect of extreme weather patterns
- Affects photosynthesis for plants
- Damage habitats (Food shortage)
- Affect animal and plant distributions
- Migration pattern of birds, insects and mammals ,may change
- Increasing migration or species dying off
- Decreases biodiversity
