ecology Flashcards
(71 cards)
1
Q
What is a habitat?
A
A habitat is the environment in which an organism lives.
2
Q
What is a population?
A
A population is the total number of organisms of the same species living in the same geographical area.
3
Q
What is a community?
A
A community is the populations of all the different species that live in the same habitat.
4
Q
What does biotic mean?
A
Biotic means living.
5
Q
What does abiotic mean?
A
Abiotic means non-living.
6
Q
What is an ecosystem?
A
An ecosystem is both the biotic and abiotic factors of an environment and how they interact.
7
Q
Why do living organisms have to compete with each other?
A
To survive and reproduce, organisms require a supply of materials from their surroundings and from other organisms that live there. These resources are often in short supply, so living organisms have to compete with each other.
8
Q
What four things do plants compete with each other for?
A
Plants compete with each other for light, space, water and mineral ions in the soil.
9
Q
What four things do animals compete with each other for?
A
Animals compete with each other for food, water, mates and territory.
10
Q
What is interdependence?
A
Interdependence is all of the species in a community relying on each other, for food, shelter, pollination, seed disposal etc. This means that if one species is removed, it can affect the whole community.
11
Q
What is meant by a stable community?
A
A stable community is one where all the species and environmental factors are in balance so the population sizes remain fairly constant.
12
Q
Give four biotic factors.
A
biotic factors:
- availability of food (if food falls, the population that eats that food will fall)
- the arrival of a new predator (so the prey species will falls existing predators will then compete, which may cause extinction)
- new pathogens (this can wipe out a population)
- one species outcompeting another so the numbers are no longer sufficient to breed
13
Q
Give seven abiotic factors.
A
abiotic factors:
- light intensity
- temperature
- water and moisture levels
- soil pH and mineral content
- wind intensity and direction
- CO2 levels for plants
- O2 levels for aquatic animals
14
Q
What are adaptations?
A
Adaptations are when organisms have features that enable them to survive in the conditions in which they normally live.
15
Q
Name the three types of adaptations.
A
types of adaptations:
- structural - body shape or structure
- behavioural - lifestyle or behaviour (eg. nocturnal)
- functional - changes to the body functions (eg. urine)
16
Q
What are extremophiles?
A
Extremophiles are organisms adapted to live in environments that are very extreme, like high temperatures, pressure or salt concentration.
17
Q
What are producers?
A
Producers synthesise molecules, which usually make glucose by photosynthesis. They are always at the beginning of food chains.
18
Q
What is a consumer?
A
Consumers eat other living organisms. Primary consumers eat producers, secondary consumers eat primary consumers and so on.
19
Q
What are predators?
A
Predators are consumers that kill and eat other animals.
20
Q
What is the predator-prey cycle?
A
predator-prey cycles:
- the number of predator and prey rises and falls in cycles in a stable community
- eg. one year, the number of prey rises as there is more grass, so predators then increase as they have more prey to eat, so the amount of prey decreases, so the predator levels decrease as there is less food, so the prey reproduces more successfully and so on…
21
Q
Why do we sample organisms?
A
We sample organisms to determine the number of organisms in an area.
22
Q
How do you calculate the total population size from random sampling?
A
total population size = (total area / area sampled) x number of organisms of that species counted in the sample
23
Q
What is a transect?
A
A transect is a line, like a tape measure or a rope.
24
Q
Why are all materials in the living world recycled?
A
All materials in the living world are recycled to provide the building blocks for future organisms.
25
How does CO2 enter the carbon cycle and then return back to the atmosphere?
CO2 can only enter the carbon cycle by photosynthesis. CO2 returns back to the atmosphere by aerobic respiration.
26
Describe the carbon cycle.
the carbon cycle:
PLANTS AND ALGAE
- take in CO2 from the atmosphere, used in photosynthesis to make carbohydrates, fats and proteins, which make up their cells
- they respire, so some is returned to the atmosphere
- when they die, carbon is released gradually
- they can be eaten by animals...
ANIMALS
- ...these animals are eaten by other animals, so the carbon is the plants becomes carbohydrates, fats and proteins for the cells of the animals
- animals respire, so some CO2 is returned to the atmosphere
- animals release waste, like faeces, and all animals die, so there is carbon in both of these
DECOMPOSERS
- eg. bacteria and fungi
- when decomposers carry out respiration, the carbon stored in the dead and waste is released as CO2, as well as mineral ions into the soil
- if lack of oxygen, the decomposers cannot function correctly, so they slowly convert dead remains to fossil fuels, which can be combusted to release CO2
27
Describe the water cycle.
the water cycle:
- almost all of the water on earth is found in oceans as salt water
- energy from the sun causes the water to evaporate from the surface of the sea
- the water vapour travels into the air, cools and condenses to form clouds
- the water in the clouds falls as precipitation
- when this hits the ground, some evaporates back into the atmosphere, but some passes through rocks and forms aquifers, rivers and streams, which eventually drains back into the sea
- plants take up water through the roots --> xylem --> out of the stomata as vapour (transpiration)
- animals take it in through drinking and eating, and release it through urine, faeces and exhaling
28
What is transpiration?
Transpiration is the passing of water through the plant. Plants take up water through the roots, which pass through the xylem and then out of the stomata as vapour.
29
What is precipitation?
Precipitation is the fall of water as rain, snow, hail or sleet. This always contains fresh water (no salt).
30
What do decomposing microorganisms do?
Decomposing microorganisms, like bacteria and fungi, carry out the decomposition of waste material. They return carbon to the atmosphere and mineral ions to the soil.
31
Why is decomposition faster at higher temperatures? What is the problem with this?
Decomposition is faster at warm temperatures as the decomposers use enzymes to break down dead plant material. This cannot be too hot otherwise the enzymes will denature and the decomposers will die. This is a problem as they release energy when they aerobically respire when they decompose materials, which will increase the temperature.
32
Why is decomposition faster if it is moist?
Decomposition is faster if it is moist as many of the chemical reactions in decay require water.
33
Why is decomposition faster if there is more oxygen?
Decomposition is faster if there is more oxygen as they need it for aerobic respiration.
34
What three conditions can increase the speed of decomposition?
to increase the speed of decomposition, we can:
- increase the temperature
- increase the moisture
- increase the oxygen levels.
35
How can we increase the rate of decomposition in plant pots?
To increase the rate of decomposition in plant pots, we mainly do this with oxygen. We can use holes in plant buckets for oxygen, or mix up the compost frequently to allow an even spread of oxygen. This also breaks up large clumps of compost to increase the surface area for decomposition to act on.
36
What happens to decomposition in the lack of oxygen?
In the lack of oxygen, decomposers carry out anaerobic decay, which produces a mixture of gases including methane, which can provide fuel on a small scale.
37
What is the effect of environmental change?
Environmental changes affect the distribution of a species in an ecosystem.
38
Name three abiotic factors that can affect organisms if changed.
abiotic factors that affect organisms if changed:
- temperature
- availability of water
- composition of atmospheric gases
39
Name the three categories of environmental change.
environmental change can be:
- seasonal
- geographical
- caused by human interaction
40
What is biodiversity?
Biodiversity is the variety of all the different species of organisms on earth or within an ecosystem.
41
Why is a greater biodiversity better?
A greater biodiversity ensures the stability of ecosystems by reducing the dependence of one species on another for food, shelter and the maintenance of the physical environment.
42
Why do humans carry out deforestation?
why humans deforest:
- to provide land for rice fields or grazing cattle
- for growing crops used to make biofuels
- this reduces biodiversity
43
Why is waste management needed?
If waste and chemical materials aren't handled properly, more pollution will be caused, which can kill plants and animals, which reduces biodiversity.
44
Name the three types of pollution and what causes them.
types of pollution:
WATER POLLUTION
- urine and faeces may be released into nearby waterways in poorer countries, but in the UK it is treated
- rivers and streams can be polluted with fertilisers from farms and it (and urine and faeces) cause dissolved oxygen levels to fall, which kills animals
- toxic chemicals can be released from factories, which kills
AIR POLLUTION
- burning coal releases acidic gases, which can cause acid rain
- burning releases smoke, which kills plants and animals
LAND POLLUTION
- landfills destroy habitats
- toxic chemicals can leach out of landfills and pollute the soil, or can just be dumped on the land
45
What four things do humans use land for?
```
humans use land for:
- building
- quarrying
- farming
- dumping
(there is less land for animals and plants, so this reduces biodiversity)
```
46
What are peat bogs and peat lands?
Peat bogs and peat lands contain large amounts of dead plant materials, and conditions there mean decay is very slow.
47
How do peat bogs and peat lands contribute to global warming?
Peat bogs and lands contain a very large amount of trapped carbon, but they are destroyed for land, or because peat is used to produce cheap compost, which releases carbon into the atmosphere. It can also be burned to release energy. It is a habitat, so destroying them decreases biodiversity. Also, when they are extracted and used for compost, it begins to decay, releasing more CO2.
48
What is the problem with compost alternatives that don't use peat?
Buying compost without peat reduces the amount of carbon released, but it is much more expensive and will subsequently increase the price of food.
49
Give the two main gases that contribute to global warming and what processes release them.
global warming gases:
- carbon dioxide - fossil fuels
- methane - bacteria in paddy fields (used to grow rice) and from cattle
50
Name three problems with some reports on global warming.
Reports on global warming can be oversimplified, inaccurate or baised if they aren't peer reviewed by scientists.
51
Give four consequences of global warming.
consequences of global warming:
- loss of habitats (reduction of ice, flooding...)
- migration of animals (and so, diseases may spread)
- migration patterns may change
- too hot for plants, or more places that a plant can grow
52
Give six ways to maintain biodiversity.
maintaining biodiversity:
- breeding programmes for endangered species
- protection and regeneration of rare habitats
- reintroduction of field margins (area of land around a field left alone) and hedgerows in agricultural areas where farmers only grow one type of crop as there is low biodiversity there
- reduction of deforestation
- reduction of carbon dioxide emissions (increasing renewables)
- recycling resources rather than dumping in landfills
53
What does trophic mean?
Trophic means feeding.
54
What is in level 1 of the trophic levels?
Level 1 of the trophic levels contains producers, which is plants and algae that make their food.
55
What is in level 2 of the trophic levels?
Level 2 of the trophic levels contains primary consumers, which are herbivores that eat plants and algae.
56
What is in level 3 of the trophic levels?
Level 3 of the trophic levels contains secondary consumers, which are carnivores that eat herbivores.
57
What is in level 4 of the trophic levels?
Level 4 of the tropic levels contanins tertiary consumers, which are carnivores that eat other carnivores.
58
What are apex predators?
Apex predators are carnivores that have no predators.
59
What is biomass?
Biomass is the dead weight of an organism. It is the living tissue of an organism including the proteins, lipids and carbohydrates that make it up. All moisture is extracted.
60
Why is dry biomass more useful than wet biomass?
Dry biomass is more useful than wet biomass as the moisture content of the organisms can vary and therefore produce inaccurate results.
61
What percentage of energy is transferred on each level of the trophic levels?
Producers only transfer about 1% of incident energy from light in photosynthesis.
Biomass transfer about 10% off energy to the next trophic level.
62
Give three reasons for losses in biomass.
losses in biomass are due to:
- not all ingested material is absorbed, some is egested as faeces
- some of the absorbed biomass is converted to waste products of metabolism (eg. CO2 and H2O in aerobic respiration, H2O and urea in urine)
- a large amount of biomass is needed for respiration (as glucose)
63
What is food security?
Food security is having enough food to feed a population.
64
Give six biological factors that threaten food security.
biological factors that threaten food security:
- increasing birth rate
- changing diets in developed countries
- new pests and pathogens that affect farming
- environmental changes that affect food production (eg. widespread famine if no rain)
- the cost of agricultural inputs
- conflicts (eg. farming is disrupted, imports not possible)
65
Describe factory farming.
factory farming:
- the efficiency of food production can be improved by restricting energy transfer
- for example, restrict movement, control temperature of surroundings, which reduces the energy used for respiration and movement
- fed high protein to increase growth
- therefore, less biomass is wasted by the animals
- control food as well so that it contains all the nutrients needed for the product so less food is wasted
66
Give disadvantages of factory farming.
disadvantages of factory farming:
- in crowded conditions, infectious diseases spread quicker (to stop this, animals are given antibiotics, but may cause them to develop antibiotic resistant bacteria)
- if crowded, animals are more stressed and more likely to fight
- may think its ethically wrong
67
Give the advantages and disadvantages of using fishing nets and modern technology to catch fish.
commercial fishing:
ADVANTAGES
- easily catch tons of fish
DISADVANTAGES
- fish stocks worldwide are falling
- once they fall below a certain level, there won't be enough fish left to breed, so they will potentially become extinct
68
Give two boundaries that the fish industry is setting to bring the fish population down to suitable levels.
boundaries on fish industry:
- the number of fish caught for each species (so remaining fish can breed and bring up level)
- net size must be large enough that smaller, immature fish can't be caught (so they can develop into adults and reproduce)
69
What are GM crops? Give an example. (this is biotechnology)
GM crops are genetically modified to produce more food, or food with improved nutritional value. For example, golden rice contains more vitamin A, which is needed for vision.
70
What do genetically modified bacteria do? (this is biotechnology)
A genetically modified bacterium produces human insulin, which can be harvested and purified to treat people with diabetes.
71
Why is the fungus Fusarium useful? Where is it grown? (this is biotechnology)
The fungus Fusarium is useful for producing mycoprotein, a protein rich food suitable for vegetarians. It is grown on glucose syrup in aerobic conditions. The biomass is harvested and purified before being made into products. It can grow large amounts in a small space.
