Biological diversity and ecosystem dynamics. Flashcards
Define habitat
The place where an organism lives
Define environment
An organisms surrounding. All the a biotic an biotic factors.
Define Ecosystem
A community of organisms that interact with each other and their environment. Can be aquatic or terrestrial.
What is the order of organising the environment?
Individual > Population > Community > Ecosystem > Biome > Biosphere
Define individual
A single organism. one animal, plant, fungus or unicellular organism.
Define population
A group of organisms of the same species.
Define Community
An ecological grouping of different species that live together and interact.
Define Ecosystem
A system formed by communities of organisms interacting with one another and their physical surroundings.
Define biome
A group of communities that have similar structures and habitats extending over a large area.
Define biosphere
All parts of earth inhabited by living things.
What are limiting factors of an ecosystem?
All abiotic and biotic factors make it possible for certain organisms to live in an area however it also limits the population growth and ability of certain species to survive.
Define the different types of population trends.
Stable/balanced- When the population number has stayed approximately the same over a number of years.
Population Explosion- When the population numbers increase dramatically.
Name and define the two types of interactions in a an ecosystem.
Interspecific- interactions between different species.
Intraspecific- interactions withing the same species.
What are the 4 types of relationships within an ecosystem?
- Predation
- Competition
- Symbiosis: Mutalism, Commensalism, Parastism
- Allelopathy
What is a predation relationship?
- When one animal (predator) obtains food by killing another (prey)
- They have an inverse population relationship.
What is mutualism?
- A relationship which is beneficial for both organisms. E.g Birds pick the knits and mites off the skin of buffalos and rhinos.
- In some cases the relationship is so strong that they can live without each other. Fro e.g. termites eat wood but cannot digest the cellulose, so protozoans do this for them.
What is a symbiosis relationship?
A relationship between two organisms where at least one benefits.
There are three types Mutalism, commensalism and parasitism.
What is commensalism?
A relationship where one organism benefits and the other is unaffected.
E.g. The remora rides attached to sharks and other fish for protection and feed of their food remains.
What is parasitism?
When one organism is used for resources. The parasite benefits and the other is harmed. E.g. ticks, lice, tapeworms.
What is a competition relationship?
When two or more organism are fighting for the same resource, abiotic or biotic.
What is competition population dynamics?
When two or more species compete one is better suited and will have a higher population than the rest even when resource and population fluctuates.
What is allelopathy?
When a plant releases chemicals that can benefits or prevent the growth of neighbouring plants. This can be done by repelling predators and parasites or poisoning competitors. E.g Blackbutt eucalyptus inhibits the growth of its own seeds that fall near the parent plant.
What are the ways trophic interaction can be shown?
Food chains, Food webs, Biomass, and Energy pyramids.
What is biomass?
Biomass Is the amount of living materials in an organism or groups of organisms. Producers have the greatest bio mass and this decrease at each trophic level due to the energy being lost at each level.
What is a niche?
The part of the ecosystem occupied by an organism. it refers to all the resources that a species uses both biotic and abiotic. No two species can occupy the same niche.
What is a trophic Cascade?
There are fundamental nuches, such as decomposers or top predators, without which the entire ecosystem can collapse. E.g. Woves at Yellowstone park or the tasmanian devil.
Define disease.
Any process that adversely affects normal functioning of an organism. It can be infectious or non-infectious.
What was the top predator till the early 20th century?
The Thylacine (Tasmanian tiger)
What are some sampling techniques?
Point sampling
Transect
Quadrant
Capture recapture.
What is the difference between distribution and abundance?
Distribution is where an species if found, usually by a place which it has high survival. While abundance is how many member is the species is found in that ecosystem.
What are some biotic factors that affect abundance?
Abundance of food, number of competitors, mates available, predators, and number of disease causing organisms.
What abiotic factors affect abundance?
Amount of light, Strength of wind, temperature variation, availability of oxygen.
What is transect sampling?
A strip is laid across area being studied and organisms along that line is drawn. It is used to determine how the community changes in an area and how commone organisms are.
What are the pros and cons of transect sampling?
Pros: time efficient, disturbance to land is minimised.
Cons: rare organisms may be missed, only suitable for sampling stationary or slow moving organisms.
How is quadrant sampling done?
A large square is thrown into the area in which you are studying. The amount of organisms withing the square is counted and noted down. The whole area in which you are sampling is measured and then the amount of organisms found in the square is multiplied by the amount of squares that can fit into that area.
What are the benefits and disadvantages of using quadrants?
Benefits: A good way to obtain data over a larger area. Disturbance to land is minimised.
Disadvantages: Only suits slow moving or stationary organisms. Time consuming. Organisms not is square will be missed.
How does capture recapture work?
Animals are captured marked and the released. After some time a group of population is recaptured and amount of tagged is counted.
What are benefits and limitations of capture recapture?
Benefits: Marking of animals should not affect their behaviour or movement.
Limitation: Time consuming and not suitable for slow moving or stationary organisms.
What is the formula to calculate abundance with capture recapture?
No. tagged x No. recaptured. Divided by No. tagged in recapture.
How is point sampling undergone?
Individual points are chosen on a map and the organisms at those points are counted. It is used to determine the range of organisms that live in an area and how common they are?
What are the advantages and disadvantages of point sampling?
Ad: Time efficient and disturbance to environment is minimised
Dis: Rare organisms may be missed.
What is natural selection?
The process of adapting to changing conditions and passing on the better suited to survive traits to offspring.
What are Darwins 4 Postulates?
- Individuals within a population have different traits and characteristics.
- Some of these traits are heritable.
- More offspring are produced than can survive because os limited resources.
- Individuals with advantageous traits will survive and reproduce.
What are the three types of adaptions?
Structural, Behavioural, and Physiological.
What is Physiological adaption?
Adaption of how the organism functions. It mostly relies of structural featues. E.g. Shivering helps to circulate the blood around your body =, which keeps you warm.
What is structural adaption?
The physical adaptions.E.g. the gypsy moth is well camouflages to protect it from predators.
What are some examples of structural adaptions in plants?
- Reduced leaf size in Spinifex.
- Drip tip on leaf
- ‘Buttressing’ roots
What is Behavioural adaption?
The behaviour of the organism. E.g. A puffer fish puffs up when it is threatened.