IE Flashcards
What are abiotic factors
Non-living components of the environment which include physical factors
What the abiotic factors
pH
Salinity
Light intensity
Temperature
Water availability
Oxygen content
What is a species’ tolerance range
A range that they can exist in
What happens at the upper or lower limits of the tolerance range
Individuals experience stress, affecting health, rate of growth, reproduction
What is a species’ optimal range
Range withing which a species is best adapted to live in. It thrives with a high population
What is a biotic environment
Living components of an ecosystem
What is an ecosystem
Consists of different groups of communities of organisms interact with each other and the natural environment
What is predation
When an organism kills and eats another organism
What is parasitism
A relationship whereby an organism benefits at the expense of another organism (host)
What is mutualism
A relationship whereby both organisms benefit
What is commensalism
A relationship whereby one organism benefits while the other is neither harmed nor benefits
Why is energy considered non-cyclic
It is unidirectional and cannot be recycled. It does not go back to the organism that produced it
How many percent of the light energy from the sun reaching the earth’s atmosphere enters the ecosystems
1%
what is the word equation for photosynthesis
water + carbon dioxide -> oxygen + glucose
what is the word equation for respiration
oxygen + glucose -> water + carbon dioxide + energy
What do you call an organism that feeds on other organisms to survive
Heterotroph
What do you call an organism that make nutritional organic substances from inorganic elements
Autotroph
What are the ways energy can be lost to the environment
Respiration
Uneaten body parts
Undigested matter (faeces)
Excretory products
What is cellular respiration
Process in which glucose is broken down in the presence of oxygen, with the release with large amounts of energy. Carbon dioxide and water are released in the process
How is the trapped chemical energy in dead organisms, undigested matter and excretory products released
It is released when decomposers break down the organic materials to inorganic materials. Decomposers used some of the trapped chemical potential energy for their needs while the rest is lost as heat
What does a food chain show
Feeding relationship among a series of organisms through which energy is transferred in the form of food
What are the differences between a food chain and food web
Food chain:
- Single linear pathway
- One organism occupies one trophic level
- Energy transferred from one level to another
Food web:
- Several interconnecting pathways
- One organism occupies multiple trophic levels
- Organisms can obtain energy from multiple different sources
Similarities between a food chain and food web
10% of energy transferred from one trophic level to another
Both start at a producer
Arrows show flow of energy
Why must nutrients be recycled
Nutrients are finite
How are nutrients returned to the natural environment
Decomposers, such as bacteria and fungi, break down dead organisms into simpler substances, returning the nutrients to the natural environment
State the importance of the carbon cycle
Ensures that there is a continuous supply of carbon dioxide for plants to carry out photosynthesis
Allows energy to be transferred from one organism to another in the form of carbon compounds, thus sustaining the lives of non-photosynthesizing organisms in the food chain
What are the processes that remove carbon from the atmosphere
Photosynthesis
Feeding
Formation of fossil fuels
What are the processes that release carbon from the atmosphere
Decomposition
Respiration
Combustion
What is a carbon sink
A carbon sink stores carbon for an indefinite period. It stores more carbon than it releases. Thus, a carbon sink is also a carbon reservoir
How much carbon dioxide released by human activities is absorbed by oceans
one third
How does the ocean store carbon
Carbon dioxide dissolved in the ocean’s water is absorbed and used by phytoplankton and algae for photosynthesis
Some carbon compounds are buried in the seabed in the form of fossil fuels
How are the oceans affected as carbon sinks by climate change
Climate change increases the temperature of water, reducing the ability of oceans to dissolve carbon dioxide
What happens when trees die
Carbon stored in their tissue is slowly released via decomposition
Their remains may be buried deep in the ground, forming coal after millions of years
What are some examples of natural carbon sources
Volcanoes, natural fires, respiration, decomposition
Impacts of deforestation
Soil erosion
Climate change
Desertification
Flooding and landslides
Explain soil erosion
Trees removed -> soil no longer protected -> directly exposed to impact of rain
No roots of trees -> nothing to hold soil down & absorb rainwater -> topsoil eroded/washed away
Explain flooding and landslides
Without roots to hold onto the soil and absorb excess water, soil gets washed off slopes onto the bases of mountains, resulting in landslides
When soil near the river gets eroded, it gets washed into the river, blocking the flow of water and causing the water level to rapidly rise, resulting in flooding
Explain desertification
The destruction of land that leads to desert-like conditions
With eroded topsoil, land becomes barren
Results in habitat loss as land is unsuitable to live in and local extinction
What is climate change
Climate change is the change in state of climate overtime due to natural variability or human activity
What is the greenhouse effect
Natural process in which greenhouse gases absorb and re-emit heat radiated from the earth to space, trapping heat
What is the link between impacts of deforestation and climate change
Deforestation further aggravates the greenhouse effect as there are fewer trees in trees to remove carbon dioxide in atmosphere. Forests cleared by burning releases carbon stored in the trees’ biomass in the form of carbon dioxide
What is deforestation
The clearing of forests to meet demands of increasing human populations
What are the impacts of climate change
- Destruction of ecosystems and widespread extinction of plant and animal species -> Rapid nature of climate change likely to exceed ability of plants and animals to migrate or adapt, resulting in increased risk of extinctions
- Rise in mosquito-borne diseases -> Dengue virus and its vector thrive in warmer climates. Due to climate change, distribution range of mosquitoes widen and some places which were traditionally dengue-free are at increasingly at risk of diseases
Explain eutrophication
- Occurs when water bodies get more nutrients than usual
- Causes rapid growth of algae
- Blocks sunlight from reaching submerged plants
- Plants die as cannot photosynthesise
- Bacteria decompose plants
- Bacteria multiply, reducing amount of oxygen
- Suffocates other organisms
What is biomagnification
Process whereby there is a progressive increase in the concentration of a substance as it moves up the trophic levels
What causes biomagnification
Water pollution due to inorganic waste and insecticides
Definition of an invasive species
When a species is accidentally or deliberately introduced into a new environment beyond their native ranges and can survive, reproduce and spread and have a negative impact on local organisms
What are the three phases for a successful invasion
Introduction
Establishment
Spread
Concerns regarding invasive species
Introduction of diseases that are new to native species
Competition with local species for resources
Economic losses
Acting as predators/parasites to native species
Habitat loss
Traits of invasive species
Fast growing
Rapid reproduction
High dispersal ability
Tolerant to a wide range of environmental conditions
High number of offspring
Lack of natural predators and diseases
Reasons for conservation
Prevent extinction
Maintain rich biodiversity
Conservation of marine ecosystems
Enforcement of laws
Clean-ups of beaches
Conservation via environmental biotechnology
Use biodegradable materials instead of plastic
Use alternative fuels instead of biofuels
