B15. Ecology and Ecosytems Flashcards
Ecology is…
The branch of Biology that studies organisms and their relationships with the living and non-living environment in which they live.
What are the 4 levels of organisation of organisms in an ecosytems?
Individual organism –> Population –> Community –> Ecosystem
Define the term ‘population’
A population is all the organisms of the same or closely-relatedspeciesin an area.
Define the term ‘community’
A community where multiple populations (ofdifferent species) living and interacting in thesame area.
What is an ecosytem?
An ecosystem is the name given to a community or group of living organisms (animals and plants) that live in a particular location. It is the interaction between living and non-living things in this environment.
What is a biotic factor and list 3 examples.
Living factors (Biotic factors):
e.g. availability of food, predators, pathogens, animals, plants etc.
What is an abiotic factor and list 3 examples.
Non-living factors (Abiotic factors):
e.g. temperature, light intensity, moisture levels, oxygen levels, soil pH and mineral content, wind intensity, carbon dioxide levels, oxygen levels.
Define the term ‘habitat’
A habitat is the natural home or environment of an animal, plant, or other organism.
What is meant by the term ‘competition’?
When there are limited resources for a plant or animal to survive and reproduce they ‘compete’ for these resources.
Name the 2 types of competition.
1) INTRA-specific competition
2) INTER-specific competition
What is meant by ‘intra-specific’ competition?
Competition between members of thesamespecies e.g. 2 lions fighting over territory.
What is meant by ‘inter-specific’ competition?
Competition between members ofdifferentspecies e.g. a lion and a tiger
Name 3 things animals compete for.
- Mates
- Territory
- Food
Name 3 things plants compete for
- Space
- Light
- Water
- Mineral ions
What is meant by the term ‘inter-dependence’?
Within a community, each species depends on other species for food, shelter, pollination, seed dispersal etc.
If one species is removed it can affect thewhole ecosystem.
This is calledinterdependence.
What is a ‘stable community’?
Astablecommunity is one where all the species and environmental factors are in balance so that population sizes remain fairly constant.
Describe the relationship between predators and prey
The predator-prey relationship is a cyclical relationship.
The size of each population directly affects the size of the other.
Why do organisms (animals & plants) need adaptations?
Organisms have features (adaptations) that enable them to survive in the conditions in which they normally live.
Name 3 types of adaptations an animal may have
Structural adaptations
Behavioural adaptations
Functional adaptations
Even thought a polar bear is very large, why does it have a SMALL surface area: volume ratio?
The polar bear does not have enough surface area on the outside to fill the even larger volume on the inside.
List some general adaptations for an animal living in a COLD environment
- Colouring is camouflaged to the environment
- Small surface: volume ratio
- Larger body size
- Streamlined shape (if lives in water)
- Layer of blubber
- Small ears
List some general adaptations for an animal living in a HOT environment
- Larger surface area: volume ratio
- Colouring is camouflaged to the environment
- Smaller body size
- Thin layer of fur (less insulation)
- Large ears
The cactus plant lives in very hot, dry conditions in the desert. Describe some of the adaptations of cacti.
- Waxy layer: to prevent water evaporating
- Thin spines instead of leaves to reduce water loss via transpiration
- Extensive root systems underground to maximise water absorption
Describe 2 examples of an ‘extreme environment’
1) Very high or low temperatures
2) Very high or low pressures
3) Very high salt concentration.
Organisms that can survive and reproduce in an extreme environment are called _______________.
Extremophiles
Which types of habitat may have an ‘extreme environment’?
An example of habitats where extremophiles are found aredeep-sea volcanic vents, where the conditions are extremelyhot, under highpressureand there is no sunlight.
What is the formula for estimating the total number of organisms in an area?
(Total area of field/area of one quadrat) x mean number of organisms
How can a quadrat be used to estimate total population size of an area?
By randomly placing quadrats within a habitat and counting the number of individuals or species within each quadrat, scientists can calculate an average density and use this to estimate the total population size of the habitat.
What is random sampling?
Random sampling involves selecting sample areas or individuals randomly within a habitat, ensuring that each part of the habitat has an equal chance of being sampled.
What could you use to ensure the areas sampled are random?
A random number generator to generate random coordinates.
How could you make your sampling investigation more precise?
Repeat with more quadrats. This will make the results more precise and more representative of the entire area.
Explain why it’s important to use random sampling when using quadrats.
Random sampling ensures that the data collected is representative of the entire habitat, reducing bias and providing a more accurate estimate of population size or distribution.
What precautions should be taken to minimize bias when using quadrats?
Precautions include randomizing the placement of quadrats, ensuring quadrats are large enough to capture variation in the habitat, and repeating sampling multiple times to account for variability.
How can quadrats be used to study changes in biodiversity over time?
By repeatedly sampling the same area with quadrats over time, scientists can observe changes in the diversity and abundance of species, providing insights into ecosystem health and dynamics.
What is a transect and how is it related to quadrat sampling?
A transect is a line or path (usually just a tape measure!) along which quadrats are placed to sample a gradient or change in habitat characteristics, such as from a rocky shore to the sea water.
What are some limitations of using quadrats for ecological sampling?
Limitations include the inability to sample mobile or hidden organisms, the potential for bias if quadrats are not placed randomly, and the time and effort required for large-scale studies.
