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
