Ecology Flashcards
1
Q
What is a habitat?
A
The place where an organism lives.
2
Q
What is a population?
A
All the organisms of one species living in a habitat.
3
Q
What is a community?
A
The populations of different species living in a habitat.
4
Q
What are abiotic factors?
A
Non-living factors of the environment e.g. temperature.
5
Q
What are biotic factors?
A
Living factors of the environment e.g. food.
6
Q
What is an ecosystem?
A
The interaction of a community of living organisms with the non-living parts of the environment.
7
Q
Why do animals have to compete to survive?
A
Animals need to use resources (biotic and abiotic) in order for them to survive they have to get the resources first or they will starve or die, These resources include: - Food, - Drink, - Territory, - Mates.
8
Q
What is interdependence?
A
- All species have to depend on each other to live*
- Species need food, if one species died out, the whole ecosystem would be effected as other animals would not be able to get food and also die out etc.
9
Q
What is a stable community?
A
When the population of an ecosystem stays roughly constant at all times.
10
Q
What are examples of abiotic factors (7)?
A
- Temperature,
- Moisture levels,
- Light intensity,
- Carbon dioxide levels,
- Wind intensity and direction,
- Oxygen levels,
- Soil PH and mineral content.
11
Q
What are examples of biotic factors (4)?
A
- New predators,
- Competition,
- New pathogens,
- Availability of food.
12
Q
What is a change in the environment caused by?
A
An increase or decrease in abiotic or biotic factors.
13
Q
Give an example of how an abiotic factor would change the environment?
A
- A greater light intensity will increase photosynithisis in plants,
- This means plants have more glucose and can grow faster as they need glucose to make energy (respiration) and create proteins for growth,
- Population will increase.
14
Q
Give an example of how a biotic factor would change the environment?
A
- If one species dominates the competition for food, they will eat a lot more than other animals,
- This means that other animals will not get enough food and die out,
- This means the predator will eventually die out due to a lack of food.
15
Q
What are adaptations?
A
Features or characteristics that organisms have to allow them to live in certain habitats, e.g. Polar bears live in the cold so have thick fur.
16
Q
What are the three adaptations?
A
- Structural,
- Behavioural,
- Functional.
17
Q
What are structural adaptions?
A
Structural adaptations are features of an organisms body such as shape or colour.
18
Q
What are some examples of structural adaptations?
A
- Fur on animals for cold climates.
- Whales have a thick layer of blubber for the cold water/ low surface area to volume ration so heat is kept in better.
- Animals in hot places have thin layers of skin so that heat can be lost easily/ large surface area to volume ratio.
19
Q
What are behavioural adaptions?
A
This is the way an animal behaves.
20
Q
What are some examples of behavioural adaptations?
A
- Some animals hibernate in winter in order to avoid the cold temperature and the harsher conditions it brings.
21
Q
What are functional adaptions?
A
These are internal adaptions that can be related to chemical reactions such as reproduction and metabolism.
22
Q
What are some examples of functional adaptations?
A
- Desert animals conserve water by sweating very little and urinating in small concentrated amounts,
- When a brown bear hibernates in winter, their metabolism lowers to conserve energy so they dont have to hunt.
23
Q
What is an extremophile?
A
They are organism that are adapted to withstand very extreme conditions.
An example of an extremophile would be microorganisms such as bacteria.
24
Q
What is a food chain?
A
It is a diagram that shows what organism is eat by what.
25
What must all food chains start with?
A producer.
26
What are some examples of producers?
- algae,
- grass,
- green plants.
27
What is biomass?
A plant or animals material used for energy production.
28
How is biomass transferred between organisms?
Eating the organism will take its biomass.
29
What is the order of a typical food chain?
Producer > Primary consumer > Secondary consumer > Tertiary consumer.
30
What happens to biomass as you go further up a food chain?
Each organism gives of less biomass because some is lost due to natural circumstances (energy production or movement.)
31
Where on the food chain is the most biomass typically?
The producers.
32
Why does the population of prey effect the population of the predators?
* Everyone in an ecosystem are interdependent on each other so the population of all species change when one does.*
- If there is more prey, it means there is more food for the predators, so population increases.
- If the population of the predator increases, then the population of the prey will decrease because more are being eaten.
- If the population of the prey decreases so will the population of the predator because they have less food.
33
What is the predator-prey cycle?
When the population of the predator changes, so will the population of the prey, and vise versa.
34
Why is the predator-prey cycle out of phase most the time (There is a delay before the other species' population changes)?
It takes time for the other species to react to the change in food supply so the population does not change for a short amount of time.
35
What is the distribution of an organism?
Where the organism can be found. An organism is more likely to live in certain environments because their bodies are better adapted for that environment.
36
What are the two ways to study distribution of an organism?
- Measure how common a species is in two sample ares (e.g. using quadrats) and compare them,
- Study how the distribution changes across an area, e.g. by placing quadrats along a transect.
37
What is a quadrat?
A square frame enclosing a known area, used to Compare how common an organism is across two sample areas.
38
How do you use quadrats to study distribution of an organisms?
- Place a 1m^2 quadrat on the ground in a random spot within the sample area,
- Count all the the organisms within the quadrat,
- Repeat steps 1 and 2 as many times as you can in the sample area,
- Work out the mean number of organisms per quadrat within the first sample area,
- Repeat steps 1 to 4 with the second sample,
compare the two means.
39
What is a transects?
A single line that is used to sector out an area for studying the distribution of organisms., it can be a tape measure to see the distance that you will be studying.
40
How do you study the distribution across an area using transect and quadrats?
- Mark out a line in the area you want to study using a tape measure,
- put down quadrats with in the area marked using the tape measure,
- Count the organisms within the quadrat then move down the measuring tape and redo this.
41
What are three environmental factors that effect the distribution of organisms?
- Availability of water,
- Temperature,
- Atmospheric gases.
42
How does availability of water effect distribution of organism?
- The distribution of animal and plant species in tropic area changes according to rainfall.
- Some animals and plants like a lot of water while some prefer the lack of water.
43
How does temperature effect distribution of organism?
- All animals and plants prefer different temperatures.
- For example, European bee-eater bird is now present in parts of Germany instead of their normal Mediterranean habitats.
44
How does atmospheric gases effect distribution of organism?
- The distribution of species changes depending on levels of polluting gases.
- For example, some species of lichen cant grow in areas where sulphur dioxide is given of in industrial atmospheres.
45
What can cause the environmental factors to change (the factors that effect distribution of organisms)?
- Seasons,
- Geographic factors,
- Human interaction.
46
What is the water cycle and its steps?
The constant recycling of water on the Earth:
- Energy from the sun evaporates the water on the Earth into water vapour,
- The water vapour is carried upwards because warm gases are less dense so rise above the air,
- The water vapour forms clouds,
- Once these clouds are heavy with water vapour and higher up in the sky, the water cools and condenses,
- The water falls as rain and the cycle restarts.
47
What is the carbon cycle ?
- The constant cycling of carbon in ecosystems is the carbon cycle.
- Carbon can be taken in from air, eating plants/ animals and back into the air via decaying dead organisms.
48
What are the steps of the carbon cycle?
- CO2 is removed from the atmosphere by green plants and algae during photosynthesis,
- This carbon is used to make glucose which can be turned into carbohydrates, fats and proteins that make up the bodies of plants,
- When plants and algae respire, some carbon is returned into the atmosphere as CO2,
- When plants and algae are eaten by animals, the animals digest the carbon and is part of the fats and proteins in their bodies,
- The carbon then moves between the food chain,
- When an animal dies, they decay from being broken down from detritus feeders and microorganisms,
- When the detritus feeders and microorganisms respire, they release carbon back into the atmosphere,
- The combustion of wood and fossil fuels from trees also releases CO2 into the air.
49
How do microorganisms and detritus feeders casue decay?
- They feed on dead animals/plants and use their waste and material to get energy,
- When they respire they release CO2 back into the atmosphere.
50
What is a use for decomposed organic matter (animals and plants)
It can be used for compost, this acts as a natural fertiliser to help plants grow faster as compost provides nutrient rich soil.
51
What factors effect the rate of decay?
- Temperature,
- Oxygen availability,
- Water availability,
- Number of decay organisms
52
How does temperature effect the rate of decay?
- More temperature will increase the rates of decay because it means enzymes that are evolved in decay will work more efficiently.
- If it is too hot the enzymes will denature and not work and it it is too cold, the enzymes will not work effectively.
53
How does oxygen availability effect the rate of decay?
- The organisms that cause decay need oxygen to respire, which they need to do in order to survive,
- Microorganisms cannot cause decay if they are dead.
- The organisms that use anaerobic respiration aren't effected by this factor.
54
How does water availability effect the rate of decay?
- Decay takes place faster in moist environments because organisms involved in decay need water in order to carry out biological processes.
- Microorganisms cannot cause decay if they are dead.
55
How does the number of decay organisms effect the rate of decay?
The more microorganisms, the more decay can take place at once.
56
What is biogas?
A gas mainly made of methane, which can be burned as fuel,
57
What type of waste is used to mass produce biogas?
Sludge waste, this can be taken from sewage works or sugar factories. (they are not the only source, just examples.)
58
How is biogas made?
- It is made by anaerobically decay of sludge waste,
- This process happens in a simple fermenter called a digester or generator,
- Biogas generators need to be kept at a constant temperature to keep the microorganisms respiring,
- Biogas cannot be stored as a liquid because a lot of pressure is required to do that, it has to be used straight away, for example in:
- Heating, cooking, lighting or to power a turbine for electricity.
59
What are the two types of biogas generators?
- Batch,
| - Continuous
60
What are the differences between biogas generators?
- Batch generators make small batches while, continuous make biogas all the time,
- Batch is manually loaded with waste, while waste is continuously fed into the continuous generator.
- Continuous generators and typically more suited for large scale productions while batch generators are not.
61
What do all biogas generators need?
- An inlet of waster material to be put in,
- An outlet for the digested material to be removed through,
- An outlet so that the biogas can be piped to where it is needed.
62
What is the general size of the sample that is measured using quadrats when trying to find the population of an organism in an area?
10%
63
What are the disadvantages of using quadrats?
- The edge effect (organisms could be on the barrier of the quadrat),
- Only gives a prediction of the population, not an exact number.
64
How do you test the effect of temperature on decay?
- Measure out 5cm^3 of lipase solution and add it to a test tube. Label this tube with an 'L' for lipase.
- Measure out 5cm^3 of milk and add it to a different test tube.
- Add 5 drops of phenolphthalein indicator to the tube containing milk.
- Then measure out 7cm^3 of sodium carbonate solution and add it to the tube containing milk and phenolphthalein. This makes the solution in the test tube alkaline, so it would turn pink.
- Put both into a water bath set to 30°C and leave the, to reach the temperature of the water bath.
- Once the tubes have reached 30°C use of calibrated dropping pipette (a pipette with a scale) to put 1cm^3 of lipase solution into the milk tube and start a stopwatch straight away.
- Stir the solution with a glass rod so the enzymes will start to decompose the milk,
- As soon as the solution loses its pink colour stop the stop watch and record the time.
- Repeat the experiment with a range of temperatures (10°C, 20°C, 30°C, 40°C, 50°C) with all temperatures do the experiment 3 times.
- Calculate the rate of decay using 1000/time.
65
What is biodiversity?
The variety of different species of organisms on Earth, or within an ecosystem.
66
Why is high biodiversity important?
- It means ecosystems are stable, because the species depend on each other for food and shelter, different species can also keep the physical environment optimum, for example, acidity in soil.
- For us as humans to survive we need enough food.
- We can use plants for medicines.
67
What do we do as humans in order to prevent the decrease in biodiversity?
- Breeding programmes for endangered species,
- Protection and regeneration of endangered habitats,
- Reintroduction of field margins and hedge rows (surround a field where only one crop is grown used to provide a habitat for a wider variety of organisms that could survive in a one crop habitat),
- Reduction of deforestation,
- Recycling resources and disposing of waste better.
68
What are reasons for an increased population?
- New medicines are being made (more effective and preserves life),
- We have more food production so less people starve.
- There are more people to breed so the rate that we increase also grows,
- life expectancy has increased because we are now more healthy.
69
What effect does increased population have on the environment?
- We need more land for farm land and housing,
- We need more electricity so we will burn more fossil fuels and take more land for power plants,
- We need more vehicles so even more CO2 is released to add to the greenhouse effect/ polluting gases are also released,
- More farming also means more polluting machines.
70
What is deforestation?
When trees are cut down on a large scale and not replaced.
71
Why do we deforest?
- Clears out land for housing,
| - Clears out land for farming (animals and crops that can be used for food and biofuel)
72
What are the issues involving deforestation?
- Trees act as carbon sinks so when burned it is all released.
- Trees left to rot release CO2 when decaying (microorganisms respire),
- less CO2 can be absorbed by the trees for photosynthesis,
- Destroys habitats so creates less biodiversity,
- Fewer medicines can be made using plants,
73
What is a peat bog?
A carbon sink made of lakes filled with dead and partially decayed plants.
74
What are the reasons to keep a peat bog?
- Historical value,
- Acts as a carbon sink (absorbs CO2),
- Important to some ecosystems (will destroy the habitat to many animals).
75
What are the damages done to bogs?
- Harvest peat,
- Drain the bog, this means peat cannot be produced,
- Afforestation (reduces the water levels),
- Animals trespass (damages the vegetation),
- Fires spread quickly,
- Invasive plants dry out the bog.
76
What is pollution?
Pollution is the introduction of contaminants into the natural environment that cause adverse change.
77
What are the 3 types of pollution?
- Water,
- Air,
- Land.
78
What are the chemicals in water pollution?
- Sewage/ fertilisers, this introduces bacteria,
- This promotes plant growth as it brings in new nutrients,
- Bacteria respires in water and takes up the oxygen, the fish will not have a sufficient oxygen supply so the fish will die out.
- plant growth uses up oxygen and also reduces the oxygen for fish.
- Other chemicals inside polluted water are: pesticides, factories toxic rubbish, toilet systems.
79
What chemicals are in land pollution?
- We use toxic chemicals for farming (e.g. pesticides and herbicides),
- We also bury nuclear waste underground,
- We dump a lot of household waste in landfill.
80
What are the chemicals in air pollution?
Smoke and acidic gases releases into the atmosphere can pollute the air, e.g. sulfur dioxide can cause acid rain.
- Cars are a source of air pollution (they release nitrogen oxide)
- Manufacturing plants (release sulfur dioxide),
- Acid rain changes PH of soil and kills plants.
81
What is global warming?
The Earth's average temperature increase due to an increase in greenhouse gases trapping excess heat under the greenhouse layer of gases.
82
What are the causes of increased CO2 levels in our atmosphere?
- More energy needs to be produced, fossil fuel burning releases CO2,
- Tress and plants are being replaced for housing so there is less plants to absorb the CO2,
- More people are around so CO2 is exhaled,
- More vehicles are being used so more CO2 is released.
83
How does the greenhouse effect work and how does it lead to global warming?
- The sun shines on the Earth and transfers heat energy with the infrared radiation,
- The Earth's surface reflects the infrared radiation back up to space,
- The greenhouse layer of gases traps some of the radiation in the Earth and does not allow it to exit back into space,
- The rest of the radiation is released back into space,
- Since the volume of CO2 has now increased in our atmosphere, there is a greater greenhouse layer so more heat is being trapped in the Earth,
- This means that the average temperature of the Earth has increased.
84
What effects does global warming have on the Earth?
- Loss of habitats:
Floods can destroy habitats, so can forest fires. (floods from ice caps melting and fires from increased temperature),
- Changes in distribution of organisms:
Changes in temperature may cause species to come close together to one place with perfect temperature, or scatter away from the imperfect environment,
- Changes in migration:
Birds, insects and mammals all migrate depending on the environment, some birds may migrate further north because it is colder.
- Reduced biodiversity:
Extinction of species.
85
What are the 4 main greenhouse gases?
- CO2 (82%)
- Methane (10%)
- Nitrous oxides (6%)
- fluorinated gases (3%)
86
How is methane mainly released into the atmosphere?
- Farming rice,
| - Raising cattle.
87
What is peat?
- It is a build up of plants that cannot fully decay because peat bogs lack oxygen,
- They act as carbon sinks.
88
What are the disadvantages of harvesting peat?
- Removes the carbon sink,
- The peat is dried up and burned as fuel, the CO2 is released this way.
- It destroys the habitats of species so will reduce biodiversity.
89
What are some examples that may deter us from maintaining biodiversity?
- *Protecting biodiversity cost money*, for example, governments sometimes pay farmers a subsidy to reintroduce hedgerows and field margins. This money could be spent else where like hospitals.
- *Maintaining biodiversity may effect other peoples local lives*, stopping deforestation would save the environment but also take jobs from previously employed people who cut down the trees. People may then move to find work and will effect the local economy.
- *There can be conflict between protecting biodiversity and having sufficient food security*, we need space to farm.
- Animals who are considered troublesome by farmers are also killed in order to maintain food security.
90
What are trophic levels?
- The different levels of the food chain, they consist one or more organisms that perform a specific role in the food
- They are numbered, trophic level 1 is at the start of the food chain, the higher the trophic levels the food chain.
91
What are the 4 trophic levels?
> Producer - a green plant or algae,
> Primary consumer - herbivores that eat the producer,
> Secondary consumer - Carnivores that eat the primary consumer,
> Tertiary consumer - Eat other carnivores, the secondary consumers, they have no predators and are also known as the APEX PREDICTOR.
92
How do bacteria and fungi decompose dead animals or plants?
They releases enzymes which break down the dead organism and the broken down substances diffuse into the bacteria or fungi to be used as food.
93
What happens to biomass as you move up the food chain?
The levels of biomass decrease because more biomass is used by the animals as you go up the food chain.
94
How is biomass lost as you go up the food chain?
- Stored in inedible parts of the dead organism,
- Animal movement/ growth,
- Temperature regulation,
- Excretion,
- Some biomass can be used in reactions (respiration)
95
What typically happens to the number of animals as you move up the food chain?
It decreases as you move up the food chain, this isn't always true but is most the time. So it is often better to look at food chains in terms of biomass.
96
What is a pyramid of biomass?
- It is a diagram that shows the relative biomass of each trophic level,
- Pyramids always start at the first trophic level (which has the most biomass) and moves up the food chain as less biomass is present.
97
How do you calculate the efficiency of biomass transfer?
efficiency(%) = (biomass transferred to next level/ total biomass available from the previous level) x 100
98
What is food security?
Having enough food to feed a population.
99
What factors effect/ threaten food security?
- Increasing population means more food,
- Diets in developing counties often change, so there will be a varying demand for food which is hard to supply for.
- New pests and pathogens could kill crops and animals,
- Farming is expensive and is hard to maintain, especially in developing countries,
- IN some parts of the world, war and conflicts limit the food and water for the country as it could be used as a battle field.
100
How can fish stocks be maintained? (We are fishing too much so fish food chains are being affected)
> Fishing quotas - there are limits to the size and number of fish that you can catch in certain areas, this stops certain species being over-fished,
> Net size - There are different limits of the mesh size of fish nets when catching different fish, this releases fish that are unwanted and allows smaller fish like shrimp to slip back out.
101
How can food production be made more efficient?
- Limiting movement so less energy is used,
- Regulate the temperature of the environment so the animals don't have to use their own energy to regulate their body temp,
- This means more energy can be used for growth to create the best produce,
102
What are examples of how animals and fish are bred efficiently?
- Livestock like calves and chickens can be factory farmed in small pens,
- Fish can as well in small cages so their movement is restricted,
- Some animals are also fed high protein foods to increase growth.
103
What are the issues with efficient food production?
- Disease can spread quickly because all animals are close,
| - Ethical issues of restricted movement and the conditions are unnatural and uncomfortable.
104
What is mycoprotein?
Food is created from fungi using biotechnology techniques in order to culture large amounts of microorganisms to create a food source.
105
What kinds of foods do mycoproteins replace?
- High-protein meat substitutes for vegetarians,
106
How is mycoprotein made?
- Fusarium is the fungi that is used,
- It is grown in aerobic conditions on a glucose syrup which is used,
- The fungal biomass is harvested and purified to produce the mycoprotein.
107
How is insulin artificially made?
- Take human DNA from a pancreas cell,
- Use a restriction enzyme to cut out the insulin production gene from the DNA,
- Extract a plasmid from a bacteria cell using the same restrictive enzyme,
- In a petridish, cut open the plasmid and insert the insulin producing gene into the plasmid and seal it,
- Put the plasmid back into the bacteria cell and allow it asexually reproduce rapidly.
108
Why do we genetically modify plants?
- Become resistant to pests,
- To get better yield from crops,
- Give the yield better nutrients (e.g. golden rice has vitamin A)
109
What are the issues around genetically modifying plants?
- People feel they should tackle poverty first,
- There are fears that countries may become dependant on the GM crops,
- Soil should be focuses on more because even GM crops cannot live without good soil.
