Speices, Communities And Ecosystems Flashcards
Species
Organisms that belong to the same species can mate and produce fertile offspring
Problems with the species concept (3)
- Organisms that reproduce asexually, such as bacteria are in effect clones
- Organisms with variation that are spread over a large geographic area
- Some species can successfully breed but are considered seperate species (e.g dog)
Communities definition
Communities are a group of populations living and interacting with each other in a common habitat
Ecosystem
A community of interdependent organisms and the interaction with the physical environment in which they live
Biotic factors of the ecosystem
- Plants
- Animals
- Bacteria
- Dead organic matter
Abiotic factors of the ecosystem
- Climate
- Temperature
- Rainfall
- Soil nutrients
- Light
- Wind
The two modes of nutrition
Autotrophic and heterotrophic
Autotrophs
Organisms which can synthesise organic material from inorganic sources provided by their environments
Heterotrophs
Organisms which derive their energy from consuming other organisms
Producers
Organisms that produces their own energy through process such as photosynthesis in plants or chemosynthesis in bacteria
Consumers
Consumers feed on living organisms by ingestion
Decomposes
Organisms that break down organic matter and play an important role in food webs and nutrient cycling
Detritivores
Detritivores obtain their organic nutrients from detritus (decomposing plant and animal matter) by internal digestion, e.g earth worms
Saprotrophs
Saprotrophs obtain their organic nutrients from dead organisms by external digestion, e.g fungi
Nutrient cycling
The use, movement and recycling of nutrients in the environment.
- Producers, consumers and deco poets allow nutrient to be cycled
Sustainability
The avoidance of the depletion of natural resources in order to maintain an ecological balance
