2.1 Species and Populations Flashcards
Define ecology
Ecology is the study of the interactions between organisms and the environment in which they live in
Define ecosystem
A community of interdependent organisms and the physical environment they interact with and the interactions between biotic and abiotic components
Define species
Speciesis a group of organisms with common characteristics that can interbreed to produce fertile offspring.
Define population
Apopulationis agroupof individuals of the same species living in the same area at the same time.
What is population size determined by?
- Births and immigration – which increase population size.
- Deaths and emigration – these decrease population size.
Define: biotic components
The biotic element of the ecosystem is anything that is living and any interactions between the living components.
What do the biotic components include?
Producers: Plants that turn energy into matter
Consumers: Animals that eat other animals
Decomposers: Organisms that breakdown waste into component parts for reuse
Interactions between living components:
- predation
- herbivory
- paratism
- mutualism
- disease and competition
Define: abiotic components
The non-living components of an ecosystem
What are some abiotic factors?
Sunlight, water, PH, salinity, precipitation
Define habitat
Ahabitatis the environment in which a species usually lives and it has the physical and biological resources that an organisms needs
What is a niche?
Thenicheis the role an organism plays and the position it holds in the environment. It includes all the interactions the organism has with the abiotic and biotic environment.
Realized niche
Realized Niche:
The ACTUAL ecological role and habitat where a species exists in nature, TAKING INTO account interactions with other species and limitation
Fundamental niche
The COMPLETE range of environmental conditions and resources where a species could potentially exist and thrive, WITHOUT CONSIDERING interactions or limitations.
What is a limiting factor? (Hint: remember there is an extra part that is IMPORTANT)
Limiting factorsare the resources in the environment that limit the growth, abundance and distribution of organisms/populationsin an ecosystem.
IMPORTANT: The size of a population and the rate at which it increases is determined by the limiting factors
What are density dependent factors? (Give ex.)
These affect the population only when it reaches a CERTAIN density
Ex. Competition, disease, parasitism and predation
What are density independent factors? (Give ex.)
These will control populations NO MATTER WHAT the density of it is.
Ex. Sunlight, temperature, water, natural disasters
Define carrying capacity
TheMAXIMUM NUMBER of individuals of a species that the environment can sustainably support in a given area.
What does the J-curve show?
Exponential population growth under ideal conditions (plenty of resources, ideal conditions)
Until the enviroment/habitat of the population reaches its carrying capacity
What type of strategists are populations that follow the J-curve and what are their characteristics?
R-strategists
Characteristics:
- High Reproductive Rate
- Early Reproduction (reach maturity at young age)
- Short Lifespan
- Small Body Size
- High Dispersal
- Generalists (able to adapt to many enviromental conditions
What does the S-curve show?
A population growth when resources are limited
Exponential growth is only possible for a short period of time because as the population grows resources are depleted and the growth rate slows and will eventually plateau off
What type of strategist follows the S-curve and what are their characteristics?
K-strategists
Characteristics:
- low reproductive rate
- delayed reproduction (reach maturity later than k strategists)
- long lifespan
- larger body size
- parental care
- all results in fewer offsprings
State the types of species interactions (hint: 5)
- Predation
- Herbivory
- Parasitism
- Mutualism
- Competition
Define Predation
Predationis where one organism (the predator) hunts and kills another (the prey) in order to provide it with the energy for survival and reproduction.
How is predation a negative feedback loop? (Hint: Explain cycle)
➕ prey = ➕ predators = ➕ predators → ➖ prey = ➖ prey = ➖ predators = ➕ prey…
Define Herbivory + Give one example of defense mechanisms developed by plants to slow down herbivory
Definition
Herbivoryis the consumption of plant material by an animal
Ex of defense mechanism
Horns or Prickles
Define parasitism
Parasitismis when anorganism (the parasite) takes nutrients from another organism (the host).
Differentiate: Ectoparsites vs endoparasites
- Ectoparasites: outside the host (think: exoesqueleto: ECTO). eg. fleas
- Endoparasites: inside the host eg. plasmodium (parastie that causes malaria
Define mutualism and give an example
Mutualismis where two organisms of different species exist in a mutually beneficial relationship. It is a type of SYMBIOTIC relationship
Example
Bacteria in the intestines of cows, bacteria eat and they facilitate the cows digestion (winwin)
Define competition
Competition is where organisms compete for a resource that is in limited supply
What are the two types of competiton? Define and give examples
- INTRAspecific competitionoccurs when members of the same species compete for a limited resource
- INTERspecific competitionis where members of different species compete for a resource that they both need.