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.
What are the sustainable development of agriculture
- crop rotation
- contour farming
- terracing
Crop rotation involves planting different crops in the same area each season to maintain soil fertility and reduce pests. Contour farming follows the land’s natural curves to slow water runoff and prevent soil erosion. Terracing creates flat steps on slopes to reduce erosion and improve water absorption for crops.Crop rotation, contour farming, and terracing are agricultural techniques used to improve soil health, conserve water, and prevent erosion.
What are the sustainable development of forestry
-cutting limits
-forest reserves
reforestation
What are the threats to biodiversity in Malaysia
- Habitat loss due to land development
- deforestation
- poaching
- overfishing
- pollution
what is population
group of organism of the same species living in the same area at the same timeand they may interbreed to produce fertile offspring
what is natality
birth rate if population
what is mortality
death rate of population
what will happen to energy in faeces and dead organisms
-energy transfered to decomposers
-used for their growth
-used for resp,released as heat
How rate of photosynthesis of the aquatic plants are affected
-less light is available
-light absorbed by water
-diff wavelength
-temprature
As the temperature increases, seaweed’s photosynthesis speeds up because enzymes work faster, but if it gets too hot, the enzymes stop working properly, and photosynthesis slows down. At low temperatures, the process is also slower because the enzymes are not active enough.
what is meant by consumer
a heterotropic organism that is incapable of using sunlight to synthesise sugar,thus must consume other organisms for nutritions
what is meant by producer
an autotropic organism that is capable of using sunlight to synthesise sugar,from water and co2 during photosynthesis,thus does not depend on other organisms for its nutritons
why is there reduction energy in gpp
due to energy losses from producers via respiration
why is there reduction in energy in npp
due to low temp,drought,low light intensity and lack of minerals
what is the formula for change in population size
change in population=(birth\natality+immigratian)-(emigratitians+deaths/mortality)
what is meant by survivorship?
Is the percentage of organisms that are able to survive at any part of their live cycles,in aparticular area
explain type 1,type 2 and type 3 survivorship
type 1:This curve shows high survival rates for………. during early and middle life, with most individuals living to old age. Mortality increases significantly only in later life stages. This is typical of species like humans and other large mammals that provide extensive parental care and protection, leading to fewer deaths in the early stages of life.
the survival curve drops sreeply after middle life as many individual die at old age
type 2:The uniform death rate across all ages is common in many invertebrates and plants. This means that the chance of death is constant throughout their lifespan, which fits a Type II curve.
Type 3:This curve is characterized by very high mortality early in life. Only a few individuals survive the early stages, but once they do, they tend to live much longer. This is common in species that produce large numbers of offspring with little to no parental care, such as many oysters, frog, and tree.
what are the density independent factors that could affect the size of population
Natural disaster
Climate extremes
Seasonal changes
what is the population size formula
(New num of individuals in first sample X number of individuals in secomd capture)/numof marked individuals
what are the asumptions made during the capture-recapture method
-the population size remain constant throught the experiment
-the organisms are captured randomly
-the marked organism mix evenly into the population
-mno emigration out or no immiration into the population
Responsibilities for sustainable fishing
- Stop illegal harvesting and poaching.
- Avoid overfishing and use proper fishing methods and quota systems.
Create marine reserves to protect habitats.
Ensure fish farming (aquaculture) is sustainable.
Invest in monitoring, enforcement, and data collection.
Protect and maintain fish habitats.
Manage the whole marine ecosystem, not just individual fish stocks.
Involve all stakeholders in fisheries management.
protect ecological and specise diversity
restock when stock is low
what are the advantages of quadrant sampling
-cost effective/inexpensive only a few materials is required
-simple to use as quadrant is unform in size and shape
-straightforward study that allows reserchers to study the distribution of plant population
-distribution of organisms is easily calculated
explain about k strategists of elephant
-elephant has high survival rate in early and the middle age.
-the produce few offspring but provide them good care and protection
-they tend to be long lived
-size of population reach carrying capacity
explain about R strategists
-Frog population face high death rate at early stage
-frogs produce very high num of offspring but no parental care
-most eggs and tadpole are eaten by other aquatic organisms
-only a few survive and reach maturatiy to reproduce.
-therefore mortality rate is low later in life
Explain the middle line
-population of……shows a constant rate of motality
-the small mammals are vulnerable to predetation and disease
-their not strong enough to protect themselves
Describe the adaptation characteristics of organismwhich use and r stategits to survive.
K-strategists:
Live in stable environments
Have a low rate of reproduction with a long gestation period
Produce few offspring
Tend to be larger individuals
Mature later in life
Have a long life span
Tend to die at an old age
Provide extensive parental care
r-strategists:
Live in unstable environments
Have a high rate of reproduction with a short gestation period
Produce a large number of offspring
Tend to be smaller individuals
Mature quickly
Have a short life span
Tend to die at a young age
Provide little or no parental care
Explain the use of quadrant sampling to determine the dominant grass species in a fields.
Prepare quadrat with size 1m x 1m.
Survey the field to be studied and divide the field into grid regions.
Identify main species of grass in the field.
Decide on the method of sampling, either systematically or randomly
Decide on the number of times in placing the quadrat.
Carry out the sampling based on the sampling method to collect the data on the density/ coverage.
Analyse the data to determine the relative density/ relative coverage of the
species of plant.
The species with the highest relative density / relative coverage is the dominant species.
To obtain a more reliable estimate, the sampling size must be large enough.
The placing of quadrat must not be selective/bias/based on personal preference.
State condition ontain more reliable estimate
To obtain a more reliable estimate, the sampling size must be large enough.
The placing of quadrat must not be selective/bias/based on personal preference.
what is meant by population distribution
this is how individuals as a population spread around the area
what is population density
is the number of individuals in a population living in a specific area at a given time
what is meant by carrying cappacity
max population size of individuals that can be supported by enviroment
what are the factors that limit the carrying cappacity
water avalability
habitat space
light intensity
food avalability
what are the phases in the growth curve
-lag phase
-log phase or exponential phase
-stationary phase
what does sustainable devlopment mean
is the development that improves the quality of life both both now and in yhe future in a way that maitains the ecological process
