Unit 3 Flashcards
Habitat
The place where an organism usually lives
Population
All the organisms of one species in a particular habitat
Community
All the populations of different species living in the same place at the same time
Ecological Niche
The role of an organism within its environment
This includes how it:
- Obtains energy
- Interacts with other species
- Interacts with its environment
Ecosystem
The combination of all the abiotic and biotic factors in a particular area
It is a self sustained system (mainly) so it only needs little energy or matter flowing in and out of it and no external energy source, this is because it functions due to photosynthesizing organisms.
Microhabitat
A small, localized habitat within a larger habitat
There can be several microhabitats in a single area.
Each microhabitat has different characteristics which give it its own microclimate
Ecoregion
A large area that has a distinct geography and contains a collection of organisms which are distinct from the area next to it.
Ecoregions differ based on their climate, geology, and the organisms that live there.
Carrying capacity
The maximum stable population size that can be maintained over a period of time in a habitat
Limiting factors that can influence carrying capacity
Biotic: Predation and Competition
Abiotic: Temperature, Light, pH, Water + Humidity and Area size
Population Size
The number of organisms from the same species in a habitat
Population Growth Rate
How quickly the size of a population changes over time
Population Growth Rate Equation
Change in population/Length of time
The stages of population size
- New population settles into an environment
- Birth and immigration exceeds death and emigration
- Density dependent factors slow population growth
- Population reaches carrying capacity
J Curve
There is a rapid increase in growth which is followed by a sudden drop
‘BOOM and then a bust’
Ectotherm
Organisms that cannot control their internal temperature
Endotherm
Organisms that can control their internal temperature
Photosynthesis
Plants convert light energy into chemical energy
Competition
Competition always exists when more than one individual wants the same limited resource
Interspecific Competition
When organisms from different species compete for the same resources
It can impact the distribution of species and the population size
Distribution of species
If one species is better adapted and able to obtain more resources, it will out-compete the other species
The population size of the less-suited species will fall, or species could occupy a new niche
Intraspecific Competition
Organisms from the same species compete for the same resources
It is more common than interspecific competition
Consequences include:
- Fluctuation in population size around the carrying capacity
Symbiosis
A close prolonged relationship between organisms of different species
At least one organism must benefit from this relationship
The three types of symbiotic relationships are:
1. Mutualism
2. Commensalism
3. Parasitism
Mutualism
Both organisms benefit from the relationship
Commensalism
One organism benefits, and the other is unaffected
Parasitism
One organism benefits, and the other is harmed
Amensalism
One organism is unaffected and the other is harmed
Biodiversity
The variability among Earths living organisms, can exist as:
Ecosystem Biodiversity
Species Diversity
Genetic Diversity
Spatial Comparison
Comparing Biodiversity over an area
Temporal Comparison
Comparing Biodiversity over time
Species
- A group of organisms which can interbreed to produce live, fertile offspring
- A group of organisms with morphological or genetic similarity
Biological Classification
A way of organising organisms so that closely related organisms are grouped together
Linnaean Classification- Taxonomic Groups
Do- Domain
Keep- Kingdom
Practicing- Phylum
Classifying- Class
Organisms- Order
For- Family
Guaranteed- Genus
Success- Species
Sexual Reproduction- K
Involves 2 parent organisms each providing a sex cell
In fertilizations, genetic material combines to form a new unique cell that develops into an organism
Asexual Reproduction- R
Involves 1 parent organism
No fertilisation takes place and no new genes are created
Offspring is genetically identical to the parent
Phylogenetic Trees
Phylogenetic trees are structures that display the evolutionary relationships between organisms
Cladograms
Cladograms are structures based largely on morphological characteristics of organisms that predict the evolutionary relationship between groups of similar looking organisms
