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20)Ecology Flashcards

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1
Q

Nitrogen cycle steps

A

1.Nitrogen fixation
2.Saprophytic bacteria
3.Nitryfing bacteria
4.Denitrifying bacteria

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2
Q

Nitrogen fixation

A

Nitrogen gas in air:
1.Lightening
-nitrogen gas in air react with oxygen and form nitrogen oxide
-Dissolves in rain
-Washed away into the soil
-Forming nitrates, which is absorbed by plants to make proteins for growth

2.Nitrogen fixing bacteria
-Growing in root nodules of leguminous plants
-Nitrogen gas in air reacts with hydrogen gas in air producing ammonium ions
-Turned into nitrogen containing compound, which is absorbed by plants to make proteins for growth

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3
Q

Saprophytic bacteria and nitrifying bacteria

A

-Nitrogen gas in air undergoes nitrogen fixation forming nitrates and nitrogen containing compounds
-Absorbed by plants to make proteins
-plants die or get eaten by animals, animals die
-Dead bodies are decomposed by saprophytic bacteria which releases extracellular enzymes
-Proteins are broken down into amino acids
-Amino acids are deaminated into ammonium ions
-Nitrifying bacteria undergoes nitrifying forming nitrites then nitrates
-Denitrifying bacteria undergo denitrifying forming nitrogen gas again

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4
Q

Role of nitrogen fixing bacteria

A
  1. Grow in the root nodules of the leguminous plants fixing nitrogen gas
  2. by allowing nitrogen to combine with hydrogen gas form air to form ammonium ions
  3. Then it forms nitrogen containing compounds in soil
  4. which is then absorbed by plants from soil by active transport or diffusion
  5. To make amino acid needed to make proteins for growth , making enzymes , hormones , nucleic acid
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5
Q

Role of saprophytic bacteria

A

1.Carries decomposition of dead animals and plants
2.By releasing extracellular enzymes that break down proteins into amino acids
3.Which will be deaminated into ammonium ions

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6
Q

Role of nitrifying bacteria

A
  1. Carries nitrification under aerobic conditions
    2.Turns ammonium ions into nitrites then nitrates in soil
    3.To be absorbed by plant needed to make proteins and nucleic acid
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7
Q

Role of denitrifying bacteria

A

1.Under anaerobic respiration
2. Denitrifying bacteria turns back nitrates into nitrogen gas

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8
Q

Carbon cycle

A

-Plants and animals respire co2 back
-Plants take in co2 for photosynthesis
-Plant and animal die
-Some undergo decomposition, decomposers respire co2 back
-Some undergo fossilisation and become fossil fuels which undergo combustion giving co2 back

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9
Q

Factors affecting carbon cycle:

A

1.Deforestation: increase in co2 concentration in atmosphere
A)Less plants so less photosynthesis ,no co2 absorbed
B)Decomposers break down dead roots, adding co2 in atmosphere
2.Burning fossil fuel: Due to increase in energy demand and no. of vehicles
3.Increase in population : increase in respiration

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10
Q

Enhanced green house effect

A
  1. Light rays from the sun hit the Earth’s atmosphere
    2.As short wave radiation
    3.Reflected as long wave radiation
    4.So Co2 traps the long wave radiation in earths atmosphere
    5.Increasing Temperature of Earth’s atmosphere
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11
Q

Positive effect of global warming

A

1.Increase in temperature
2.Increase in co2 conc.
3.Less limiting factors
4.Increase rate of photosynthesis
5.Increase in growth
6.Increase in crop yield

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12
Q

Negative effects of global warming

A

1.Melting ice caps
2.Causing rise in sea level, floods
3.Destruction of habitat
4.No food, shelter, breeding site
5.Increase risk of extinction

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13
Q

Food chain

A

Represents the energy flow from one organism to another

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14
Q

Food web

A

Several food chains linked together

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15
Q

Advantage of food web

A

Each living organism can have more than one food source

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16
Q

Trophic level

A

Position of an organism in a food web/chain

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17
Q

How 90% of energy in plant is lost to surrounding

A
  1. Non edible parts in plant
  2. Active transport of minerals
    3.Lost in respiration
    4.Part of light is not absorbed
    5.Dead leaves/roots
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18
Q

How 90% of energy in animals is lost to surrounding

A

1.Movement
2.Respiration
3.Excretion
4.Undigested food

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19
Q

Explain why it is an advantage to have a shorter food chain with fewer trophic

A

1.As the trophic level moves up more energy is lost to surrounding and less energy is transferred
2.Only 10% of the energy is transferred while 90% of energy is lost
3.Energy is lost by excretion, movement, respiration, egestion.
4.So less energy is available for organisms at higher trophic level
5.So less energy to support life of large population

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20
Q

Explain why there are fewer organisms at the top of the food chain

A

1.As the trophic level moves up more energy is lost to surrounding and less energy is transferred
2.Only 10% of the energy is transferred while 90% of energy is lost
3.Energy is lost by excretion, movement, respiration, egestion.
4.So less energy is available for organisms at higher trophic level
5.So less energy to support life of large population
6.DECREASE IN POPULATION MAY BE DUE TO disease, hunting, introducing new species increasing competition on food resources, habitat destruction

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21
Q

Explain why its better to feed on plants rather than animals

A

1.As the trophic level moves up more energy is lost to surrounding and less energy is transferred
2.Only 10% of the energy is transferred while 90% of energy is lost
3.Energy is lost by excretion, movement, respiration, egestion.
4.So less energy is available for organisms at higher trophic level
5.So less energy to support life of large population
6.PLANTS ARE AT THE FIRST TROPHIC LEVEL MEANING THEY HAVE THE MOST ENERGY

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22
Q

Suggest a disadvantage for feeding on plants only

A

-Plants dont contain all essential amino acids
-Parts of plants are not digested, so are egested

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23
Q

Outline how the energy in the primary consumers is used to produce biomass in the secondary consumers

A

-Primary consumer is eaten by secondary consumer
-Primary consumer contains chemical energy
-So energy is transferred from primary to secondary consumer
-Secondary consumer digest food particles
-Produces small soluble molecules e.g. glucose and amino acids
-Glucose is used in respiration to release energy used in growth and cell division, and building of large biological molecules as proteins
-Excess glucose stored as fat or glycogen

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24
Q

Type of pyramids

A

1.Pyramids of numbers:
sometimes not pyramid shaped as it doesnt take into consideration the size of the organisms

2.Pyramid of biomass:
-Indicate how much food is available at each trophic level
-Represents energy available at each trophic level

3.Pyramids of energy:
-Each column represents amount of energy present in each trophic level
-Where 10% of energy being transferred from lower trophic level to higher one
-There is energy lost at each trophic level so pyramid shaped

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25
Ways to increase food production (8)
1.Modern machinery 2.Artificial fertilisers 3.Use of pesticides 4.Monoculture 5.Modern irrigation system 6.Live stocks 7.Genetic engineering 8.Deforestation
26
Using modern machinery(+ve and -ve effects)
Positive effect: -Cultivation and harvesting will be quicker, more land area can be used Negative effect: -Burning fossil fuels, so production of co2, which is a green house gas, traps more heat, enhanced green house effect, global warming -Soil is compacted so difficult for rain water to penetrate soil
27
Use of artificial fertiliser
Positive effect: -Increase soil fertility -Increase in concentration of nitrates, magnesium and phosphate in soil -More nitrates for more protein synthesis and growth -More magnesium for making chlorophyll for more absorption of... -More phosphate for nucleic acid Negative effect: -Eutrophication -Promotes the growth of algae on water surface -Blocks light -Plants under water cant carry photosynthesis -Plants will die, so bacteria will grow and decomposers which respire aerobically -Absorbing O2, so decreasing oxygen concentration in water -Death in aquatic plants and animals
28
Use of pesticide
Positive effect: Kills pests -less damage of crops -Less competition on minerals, nutrients, water and light -Increase crop yield Negative effect: 1.Non biodegradable -Bioaccumulation -Toxic concentration in animals -Disrupt food chain -Decrease biodiversity -Increase risk of extinction 2.Herbicides: Kill useful plants Insecticides: Kill useful insects as pollinators 3.Weeds or insects might become resistance to herbicides or insecticides
29
Monoculture
Positive effect 1.Efficient food production, less land area is required 2.Mechanical harvesting is easier Negative effect: 1.Use up minerals from soil -Decrease in soil fertility, leading to use of artificial fertiliser, eutrophication, damage in aquatic life 2.Increase risk of spread of diseases -Crowded place with same type of plant 3.Increase in pest population: -More use of insecticides killing pollinators, non biodegradable causing bioaccumulation 4. Decrease in other pest population -Disrupt food chain, decrease in biodiversity, increase in risk of extinction 5.Deforestation: -Destruction of habitat, so no food, shelter, breeding area, so decrease in biodiversity, increase in risk of extinction
30
Modern irrigation system
Positive effect: -Provides water to growing plants, removing a limiting factor Negative effect: -Leaching of minerals from soil
31
Selective breeding
Positive effect: 1.Improvement in variety of animals and plants 2.Farmers use high energy food to feed animals, increase production of milk, meat and wool 3.Regular medication given to animals so they stop developing diseases 4.Animals are kept under controlled temperature to maximize growth rate Negative effect: 1.Spread of disease due to over crowded 2.Increase in dosing of antibiotic, so bacteria may become resistant to antibiotics 3.Decrease in biodiversity, increasing risk of extinction 4.Waste from animals may cause pollution
32
Genetic engineering
Positive effect: 1.Crops resistant to herbicide -Less competition, more growth, inc. in crop yield 2.Crops toxic to insects -Less use insecticides 3.Make food more rich in vitamins/minerals 4.Plants modified to be pathogen resistant 5.Drought resistant plants Negative effect: 1.Creates super weed, if herbicide resistant plant cross pollinates with wild relative 2.Bacteria might escape from labs resulting in unpredicted consequences 3.Seeds are more expensive for farmers 4.New organism might be patented
33
Positive effect of deforestation Why deforestation
1.Increase land area available for food production 2.Get wood for buildings and furniture 3.Urbinization 4.Wood as a source of energy
34
Negative effect of deforestation on atmosphere
-Less plants, less photosynthesis, less oxygen conc. more co2 conc. -Grabs more heat, as its a green house gas, increasing temperature of earth causing enhanced greenhouse effect -Leading to global warming, melting of icecaps, increase in sea level, floods, destruction of habitats, no food, no shelter, no breeding site, disruption of food chain, decrease in biodiversity, increasing risk of extinction
35
Negative effect of deforestation on animals
1.Destruction of habitats 2.No food, shelter, breeding cites 3.Disruption of food chain 4.Decrease in biodiversity 5.Increasing risk of extinction
36
Negative effect of deforestation on soil
1.Less roots to absorb water, water logging 2.Less root to hold soil in place, rain and wind can easily remove top layer of soil causing soil erosion and desertification
37
Negative effect of deforestation on rivers
Soil washed into rivers so causing floods
38
Eutrophication by excessive use of fertiliser
1.Fertiliser drains into rivers 2.Promotes growth of algae 3.Blocks sunlight from reaching aquatic plants 4.Cant photosynthesise 5.Death of aquatic plants 6.Promotes growth of bacteria and decomposers on dead plants 7.Respire aerobically, decreasing oxygen concentration in water 8.Death of aquatic animals
39
Solution of eutrophication by excessive use of fertiliser
1.Control use of fertiliser -Only apply when crops are growing -Never apply to empty field -Dont apply when theres rain -Dont spray near rivers 2.Use manure -Its heavier, so not easily washed away by water, releases minerals slowly allowing efficient absorption of minerals
40
Eutrophication by throwing untreated sewage in water/rivers
1.Throwing untreated sewage in water 2.Promotes growth of algae 3.Blocks sunlight from reaching aquatic plants 4.Cant photosynthesise 5.Death of aquatic plants 6.Promotes growth of bacteria and decomposers on dead plants 7.Respire aerobically, decreasing oxygen conc. in water 8.Death in aquatic plants and animals
41
Solution of eutrophication by untreated sewage in water
Sewage treatment
42
Causes of famine
1.By increasing population -Increase in food demand -Unequal distribution of food -Limited areas for farming due to urbanisation -Pollution -Poverty 2.Natural disasters -Earthquakes -Droughts -Diseases -Floods(soil erosion) 3.Wars -Burns crops -Farmers join military
43
Reasons for unequal distribution of food
1.More suitable environment conditions 2.Advanced agriculture
44
Solution for unequal distribution of food
Donate food to poor countries until self sufficiency which can be achieved by educating farmers about modern farming methods
45
Human influence on air pollution
1.Green house gases A)Co2: burning of fossil fuels leading to enhanced green house effect B)Methane: -Decay of rubbish in land fill -Cattle chewing -Decomposition of vegetation by bacteria C) CFC: fridges, AC 2.Nuclear fall out -Nuclear explosion, mutation, damage DNA, cancer, deformed babies, death
46
Human influence on deforestation
1. On soil: soil erosion and desertification 2. On animals: loss of habitat, disruption of food chain, decrease in biodiversity and increase risk of extinction 3. on atmosphere: increase CO2, enhanced green house effect, global warming 4. Rivers: floods
47
Human influence on water pollution
1.Untreated sewage and fertilisers: causing eutrophication and spread of disease 2.Pesticides: Bioaccumulation, killing useful organisms (pollinators) 3.Plastics Nonbiodegradable
48
Nonbiodegradable plastic effects
A)Plastic containers have harmful chemicals B) Block airways of animals, death C) Block digestive system of animals if mistakenly swallowed, death D) Block sunlight for photosynthesis E)Block flow of water in streams, stationary water, spread of diseases, oxygen conc. in water decrease/ damage of aquatic animals F) Bioaccumulation
49
Conservation
Process of looking after natural environment to A) maintain biodiversity of plants and animals (biotic) B) Maintain natural resources for coming generations (Abiotic)
50
Why conserve plants and animals (biotic)
1.Providing habitats for many species 2.Maintaining resources like food availability, shelter and breeding sites 3.Avoid disruption of food chain 4.Maintain biodiversity 5.Reduce risk of extinction 6.More genetic diversity 7. Tourism 8. Increase research 9. Keeping beauty of nature for those who enjoy it
51
Why conserve non living resources (biotic)
Maintain natural resources Fossil fuels are non renewable resource, conserved for generation
52
Define of endangered species
Species that are found in low population, hard to breed and maintain genetic diversity
53
Problems of having small population (or self population)
1.Increase in inbreeding, less variation, increase in homozygosity higher chance for genetic diseases to be inherited, less adaptation, less selection and evolution, increase in competition, less survival, decrease in biodiversity, increase extinction
54
What causes decrease in population
1.Hunting 2.Pollution 3.Deforestation/ habitat destruction 4.Lack of food 5.Spread of disease 6.Increase in competition by introduction new species 7.Climate change
55
Ways to conserve species
1.Captive breeding programs 2.Conserving fish stocks 3.Restore damaged habitats, monitor and protect species and their natural habitat 4.Keeping natural resources like conserving forests
56
Captive breeding programmes
Enclosing animals in suitable places, keeping them away from predators, diseases and allowing them to breed(AI or IVF) then reintroduce them back to their natural habitat, -This is to maintain genetic diversity to increase gene pool
57
Conserving fish stocks
1.Fish restocking: by breeding large number of fish 2.Legal quotes : by catching only certain certain quantities and species of fish 3.Control size of mesh: to allow immature fish to escape 4.Educate people
58
Conserving forests
1.Governmental rules: refuse to grant license for cutting trees 2.Selective felling: Cutting small part of trees so remaining trees will provide habitats for some animals 3.Coppicing: Cutting down tree leaving 1 meter to regrow 4.Plant new trees: To replace old ones 5.Educate people about importance of conserving forests
59
Seed banks
Where seeds can remain dormant for many years and germinate when conditions are right Easier to store, takes less space So collect and store seeds of endangered species then reintroduce them into their natural habitat
60
Population
Group of the same species, living at the same place, during same period of time
61
Community
All different species, living at the same place, during same period of time
62
Ecosystem
Living and non living organisms interact together in a particular part of the environment
63
Habitat
Part of environment providing food, shelter and breeding area
64
Adaptation
Resulting from natural selection where living organisms develop a special feature to suit their environment
65
Fitness
Ability of an organism to survive and reproduce in the environment
66
Adaptive features
Inherited feature that helps organism survive and reproduce in environment

Biology (20 decks)

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