Exam Exams Flashcards
Define the term species
A group of organisms that interbreed and are capable of producing offspring
Define term Population
A group of organisms of the same species living in the same area at the sometime, which are capable of interbreeding
Define term Habitat
The environment in which species normally lives
- Habitats can change over time as a result of migration
Define Niche
A species´share of a habitat and resources in it. An organism´s ecological niche depends not only on where it lives but also on what it does
- A niche describes the particular set of abiotic and biotic conditions and resources in which an organism or population responds
- The niche is a complete description of a species- where, when, how it lives
- Two species cannot share the same niche
- Species with overlapping niches will complete with eachother
Compare fundamental and realized niche
Fundamental niche
- Defines the physical conditions under a species might live, in absence of interaction with other species
- May not be fully occupied , due to the presence of competing species, the absence of required positive species interactions, or dispersal limitations
Realized niche
- Interactions such as competition, predation,disease and parasitism may restrict the environments in which a species can live; these more restricted conditions are realized niche.
- Defined by the presence of competing species, the absence of required positive species interaction, or dispersal limitations
Define Ecosystem
- an environment in which living organisms and non - living factors interact
Define ecology
The study of how living things interact with each other and the environment
Define Adaptation
Organisms that have special features/behavior which help them to be successful in their
habitat so they have a good chance of survival
What are the environmental factors that constantly change ecosystems ?
- Abiotic and Biotic factors
What are abiotic factors?
- physical/environmental factors( non-living)
1. Water
2. Temperature- few living organisms can grow outside the range 0-40 degree Celsius.
3. Light- needed for photosynthesis
4. Oxygen content
5. Minerals- potassium, nitrogen etc.
What are biotic factors?
- Competition- for food, light, water, space
- Predation
- Disease- caused by microorganisms
- Effect of humans- Industry, farming, forestry, transport, housing
Population of interactions
- Ecosystems contain many different species with different interactions being shown between populations.
Competition between organisms can be:
- intraspecific- competition between members of the same species
- interspecific- competition between members of different species
Define competition
- When resources are limiting populations compete in order to survive such as food, water, light , space etc..
What are the different interactions between species
-Mutualism
Both organisms benefit- a necessary symbiotic relationship
Lichen(fungus/algae)
E.g Cleaner wrasse fish and shark
-Commensalism
one benefits, the other unharmed or benefits
E.g Anemone/ clownfish
-Paratism
One organism lives in or another obtaining food from it- rarely kills it
E.g Tick on on dog
Fungus of athlete’s foot
-Predation
One organism eats another
E.g Pitcher plants on insects
-Allelopathy
A detrimental relationship in which one plant reduces the growth of another nearby by releasing inhibitory
E.g Eucalyptus trees
How can the abundance of one species can affect the abundance of the other?
- In Intraspecific competion can affect the carrying capacity of a population. Populations with higher density will experience more intraspecifc competition and therefore have a lower carrying capacity due to the lower amount of food available.
- In Interspecific competion species with similar niches will compete for similar resources, lowering the carrying capacity of one or two species.
