ecology Flashcards
what is meant by niche
-physical area dwelt in by a organism and its functional role in a community
-functional role are dependent on the dwelling and the activities of the organism
What is meant by habitat-
-a natural area where an habitat lives and grows
-habitat consist of biotic and abiotic factors that influence the living of an organism
what is meant by ecosystem
-ecosystem consist of biotic and abiotic components
-these components interact and function together to form a stable system
-biotic components consist of producers,consumers and decomposers
-there is a continuous flow in ecosystem
-example of an ecosystem is tropical rainforest that has large trees,insects,birds,tigers and non living components like soil,rock and organic remains.
what is meant by community
-consist of population of different species living in an area interacting with each other.
-community is unstable and is constantly changing through succession to reach climax community.
-a climax community has reached equilibrium in terms of energy flow
-it is dynamic equilibrium
-community is affected by enviroment
-example is pond community that has surface plants,marginal plants such as elodea,snails,fish and large fish.
what is meant by population
-a group of organisms of the same species living in the same area at the same time and they may interbread to produce fertile offspring
write the ecosystem concept in sequence
1)organisam
2)population
3)community
4)ecosystem
5)biosphere
what is an organism
-living things that can be unicellular or multicellular
What is the zonation of a lake ecosystem based on?
Light penetration (photic and aphotic)
and Distance from shore and water depth (littoral, limnetic)
what are the importance of sustainable development
- Keep species populations healthy and prevent extinction.
- Protect ecosystems and conserve biodiversity.
3.maintain natural processes in ecosystems. - safeguard the potential for species and ecosystems to evolve.
- Sustain renewable resources.
- Allow humans to use ecosystems without harming them.
What is the photic zone of a lake?
The upper part of the lake where light is sufficient for photosynthesis.
What is the aphotic/profundal zone of a lake?
The deep open water region that does not receive light.
what is meant by the compensation point
The point between photic and aphotic where the rate of photosynthesis equal to the rate of respiration
tell where the compensation point is located
why are not all light energy falling on the producers is used in photosynthesis
-light of wrong wavelegth
-light misses the chloroplast
What is the littoral zone of a lake?
The area near the shore that receives sunlight, extending down to the depth where rooted plants stop growing.
What is the limnetic zone of a lake?
The open surface water away from the shore.
What are the biotic components of the photic zone?
Mainly primary producers (plants) due to sufficient sunlight for photosynthesis.
Why is there a significant energy loss between trophic levels?
Only about 10% of the energy from one trophic level is transferred to the next. The remaining 90% is lost as heat through processes like respiration, excretion, movement, growth, and photosynthesis.
What are the key steps of the phosphorus cycle, and how do human activities affect it?
No atmospheric phosphorus: Phosphorus is not found in the atmosphere, unlike carbon and nitrogen.
Sedimentary cycle: Phosphorus cycles between land, oceans, and back to land. Rocks are the major reservoir, where phosphorus is found as phosphate.
Weathering and erosion: Weathering breaks down rocks, releasing phosphate. Erosion then carries phosphate into the soil, where plants absorb it through active transport.
Biological importance: Phosphate in plants is used to form vital molecules like phospholipids, ATP, and nucleic acids like dna and rna.
Transfer in food web: Phosphorus is transferred to animals that eat plants, and it forms key components in bones and teeth.
Decomposition: Decomposers release inorganic phosphate back into the soil and water.
Aquatic cycle/absorption: Phosphate enters aquatic ecosystems, supporting algae and aquatic plants, and moves through aquatic food webs.
Return to land: Some phosphate returns to land via birds (guano), and geological uplift can expose ocean sediments.
Human impact and leaching: Farming practices cause leaching, where excess phosphate from fertilizers washes into water bodies through runoff. This increases phosphate levels in aquatic ecosystems, leading to eutrophication (algal blooms).
how consumers such as carnivores has phosphate
-by eating other animals which which obtain phosphate from plants
state one function of phosphate in living organsims
an essential component of nucleic acid
explain the sulpur cycle
Volcanic eruption spill out sulphur dioxide, gas into atmosphere
Rain brings it down forming acid rain and Sulphate dissolve in soil .SO in the soil are absorbed by plants and used in the synthesis sulphur containing amino acids and used in the formation of proteins
The sulphur containing organic compounds are passed to the herbivores when they eat the plants
The herbivores may transfer the sulphur to carnivores or top predators through
the food chain.
When the animals and plants die, they are decomposed aerobically back to form
sulphates .The sulphur containing organic compounds in the organisms may be anaerobically converted into sulphides.
Sulphates in the soil will change into sulphide by sulphate reducing bacteria Desulphovibrio
Sulphides are converted in the hot spring into sulphur by bacteria Chlorobium and Chromatium
Sulphur is then oxidises by bacteria Thiobacillus to form sulphates back to the soil.
explain the carbon cycle
Carbon in Water: Carbon dioxide (CO₂) from the atmosphere dissolves in water, forming bicarbonate ions (HCO₃⁻), which serve as a carbon source for aquatic organisms like algae.
Aquatic Respiration: Aquatic organisms release CO₂ during respiration, which also converts to bicarbonate (HCO₃⁻) in the water.
Terrestrial Photosynthesis: Land plants absorb atmospheric CO₂ during photosynthesis, converting it into sugars, which are then used to produce carbohydrates, fats, proteins, and nucleic acids.
Carbon Transfer in the Food Chain: Carbon moves through the food chain as plants (producers) are consumed by animals (consumers). When organisms die, decomposers (bacteria and fungi) break them down, recycling carbon back into the ecosystem.
Respiration and Combustion: The carbon from respiration and combustion (e.g., burning fossil fuels or wood) returns to the atmosphere as CO₂.
Limestone Erosion: Erosion of limestone, which stores carbon, releases CO₂ into water and the atmosphere, contributing to the continuation of the carbon cycle.
Carbon Fixation: Carbon fixation refers to the process where organisms, primarily through photosynthesis, convert inorganic CO₂ into organic compounds, such as glucose.
