2.2 - Communities And Ecosystems Flashcards
What is a community
A community is a group of populations living and interacting with each other in a common habitat
Is an ecosystem a community
An ecosystem is a community and the physical environment it interacts a with
Give an example of how a community interacts with its physical enviroment to create a unique ecosystem
An example of an ecological community is a coral reef ecosystem. The coral reef ecosystem consists of various populations of living organisms such as coral polyps, fish, crustaceans, mollusks, algae, and other marine creatures that interact with each other and their non-living environment.
These organisms form a complex community that is adapted to the specific conditions of the coral reef ecosystem, including the temperature, light, water chemistry, and physical structure of the reef. Coral reefs require specific abiotic factors such as warm water temperatures, clear and shallow water, and high levels of sunlight to survive.
The interactions among the different species in the community help to maintain the health and stability of the ecosystem. For example, the corals provide a habitat for fish and other organisms, while the fish help to keep the reef healthy and clean by grazing on algae that grows on the corals and by removing dead or decaying matter. In these ways, the coral reef community and its physical environment are intricately connected and interact with each other to create a diverse and productive ecosystem.
What is photosynthesis
Primary producers in the majority of ecosystems convert light energy into chemical energy in the process of photosynthesis
The photosynthesis reaction is:
Carbon dioxide + water —> glucose + oxygen
What are the inputs of photosynthesis
sunlight as energy source, carbon dioxide, and water
What are the processes of photosynthesis
inside chloroplasts, chlorophyll captures certain visible wavelengths of sunlight energy and stores this as chemical energy
What are the outputs of photosynthesis
Glucose and oxygen
What are the transformations of photosynthesis
light energy is transformed into stored chemical energy (in organic matter e.g. carbohydrates, fats and proteins)
What does the process of photosynthesis convert
Photosynthesis produces the raw material for producing biomass
The glucose produced during photosynthesis is used as an energy source for the plant but also as the basic starting material for other organic molecules (e.g. cellulose and starch)
What does photosynthesis transfer light energy into
Chemical energy in biological molecules
What are most of the sugars synthesised by plants used for
Most of these sugars synthesised by plants are used by the plant as respiratory substrates
- A respiratory substrate is a molecule (such as glucose) that can be used in respiration, to release energy for growth
What are the minority of sugars used for in photosynthesis
- Starch - a complex carbohydrate molecule (formed from many glucose molecules) that acts as a short-term energy storage molecule
- Cellulose - another complex carbohydrate molecule (also formed from many glucose molecules) that acts as a structural component of plant cell walls
- Lipids - plant cells can convert the sugars produced during photosynthesis into lipids, which act as another type of (longer-term) energy storage molecule
- Proteins - plant cells can also combine the sugars produced during photosynthesis with nitrates to make amino acids, which can then be used to produce proteins
What is biomass
The biomass is the mass of living material. It can also be thought of as the chemical energy that is stored within the plant
What is respiration
Respiration and photosynthesis can be described as processes with inputs, outputs, and transformations of energy and matter
Respiration is the conversion of organic matter into carbon dioxide and water in all living organisms, releasing energy
What is aerobic respiration
A chemical reaction which converts glucose into cellular energy in the presence of oxygen
What is the formula for aerobic respiration
Glucose + oxygen —> carbon dioxide + water
What are the inputs of aerobic respiration
Organic matter and oxygen
What are the processes in aerobic respiration
Oxidation processes inside cells
What are the outputs of aerobic respiration
Release of energy for work and heat
What are the transformation of aerobic respiration
Stored chemical energy is transformed into kinetic energy and heat
What does reparation do to the entropy of a ecosystem
During respiration, large amounts of energy are dissipated as heat, increasing the entropy in the ecosystem while enabling the organisms to maintain relatively low entropy/high organisation
What are trophies levels
The trophic level is the position that an organism occupies in a food chain, or a group of organisms in a community that occupy the same positions in a food chain
What are the 5 trophies levels
- Producers
- Primary consumers
- secondary consumers
- Tertiary consumers
- Quaternary consumers
What organisms are found in tropic level 1
Plants and algae – produce their own biomass using energy from sunlight
What organisms are found in tropic level 2
Herbivores – feed on producers
What organisms are found in tropic level 3
Predators – feed on primary consumers
What organisms are found in tropic level 4
Predators – feed on secondary consumers
What organisms are found in tropic level 5
Predators - feed on tertiary consumers
What are producers
Producers (autotrophs) are typically plants or algae and produce their own food using photosynthesis and form the first trophic level in a food chain
Exceptions include chemosynthetic organisms that produce food without sunlight
How is chemical energy transferred to primary consumers
The chemical energy stored in producers is then transferred to primary consumers as they consume (eat) producers
How can the chemical energy be transfered for apex chemical after they die
Apex predators are at the very top of the food chain – they are carnivores with no predators
The chemical energy stored within apex predators can be passed on to decomposers when apex predators die and are decomposed
What are feeding relationships
Feeding relationships involve producers, consumers and decomposers
These can be modelled using food chains, food webs and ecological pyramids
What are decomposers
The net primary production (i.e. the chemical energy) of producers is also available to another group of organisms known as decomposers
What are the 2 main groups of decomposers
Bacteria and fungi
What is the role of decomposers in the ecosystem
They break down dead plant and animal material
How do decomposers break things down
- Secreting digestive enzymes onto the surface of the dead organism
- These enzymes break down the dead matter into small soluble food molecules
- These molecules are then absorbed by the decomposers
What is the other benefit of decomposing
This process of decomposition also helps to release organic nutrients back into the environment (e.g. the soil), which are essential for the growth of plants and other producers
What are the three ecological pyramids
- pyramid of numbers
- pyramid of biomass
- pyramid of productivity
What does a pyramid of numbers show
They are quantitative models usually measured for a given time and area
A pyramid of numbers shows how many organisms we are talking about at each level of a food chain
The width of the box indicates the number of organisms at that trophic level
What is a pyramid of biomass
A pyramid of biomass measures the amount of biomass present at each trophic level at a specific point in time and represents the standing stock of each trophic level
What is a pyramid of productivity
Pyramids of productivity show the flow of energy through trophic levels, indicating the rate at which that energy is being generated
Pyramids of productivity illustrate the amount of energy or biomass of organisms at each trophic level per unit area per unit time
What is bioaccumulation
Bioaccumulation is the build-up of persistent or non-biodegradable pollutants within an organism or trophic level because they cannot be broken down
This means that organisms at higher trophic levels (such as top predators) may accumulate higher concentrations of pollutants than those at lower trophic levels
What is biomagnification
Biomagnification is the increase in the concentration of persistent or non-biodegradable pollutants along a food chain
As pollutants are passed up the food chain from one trophic level to the next, they can become more concentrated due to the decrease in total biomass of organisms at higher trophic levels
