Ecology Flashcards
(47 cards)
Define species.
Organisms which can interbreed and produce fertile offspring.
What are the two conditions of interbreeding offspring?
- Members from one species can’t produce fertile offspring with members of another species.
- When members from two species do produce offspring by crossbreeding, the hybrid is reproductively sterile (Eg. mules).
Define population.
A group of organisms of the same species living in the same area at the same time.
How do different populations of the same species exist?
Distance creates reproductive isolation, but if those populations can functionally interbreed they are still classified as the same species.
Define community.
A group of organisms living and interacting with each other in an area.
Define habitat.
The environment in which a species normally lives/the location of a living organism.
Define ecosystem.
A self sustaining community of organisms living an a physical environment.
Define ecology.
The study of relationships between living organisms and their environment.
What are autotrophs?
Organisms which synthesise organic molecules from inorganic substances - self feeding.
What are the two ways autotrophs produce their own organic molecules?
- Photosynthesis - photoautotrophs which make organic compounds using energy derived from the sun.
- Chemosynthesis - chemoautotrophs make organic compounds using energy derived from the oxidation of chemicals.
Why are autotrophs referred to as producers?
Because they synthesise their own organic molecules.
What are heterotrophs?
Organisms which obtain organic molecules from other organisms.
What are the three types of heterotrophs and how do each obtain their organic molecules from other organisms?
- Consumers - Ingest organic matter which is either living or recently killed.
- Detrivores - Ingest non-living organic matter.
- Saprotrophs - Feed on non-living organic matter by secreting digestive enzymes and absorbing the products.
Why are heterotrophs referred to as consumers?
Because they cannot produce their own organic molecules and obtain it from other sources.
What are mixotrophs?
Organisms which can use both forms of nutrition depending on resource availability.
Which environment do autotrophs obtain their nutrients? Which nutrients are common?
Abiotic environment.
Carbon, nitrogen, hydrogen, oxygen and phosphorous.
What is the initial energy source for most communities?
Light (sun).
What are consumers?
Heterotrophs which feed on living organisms by digestion.
Name and describe the three types of consumers.
- Herbivores - feed on plant matter
- Carnivores - feed on animal matter
- Omnivores - feed on plant and animal matter
What are scavengers?
Types of consumers which feed on dead, decaying matter rather than hunting live prey.
What are detrivores?
A type of heterotroph which obtain nutrients from non-living organic sources, via internal digestion.
What are saprotrophs?
Organisms that live on non-living organic matter and release enzymes to absorb nutrients.
Why are saprotrophs commonly referred to as decomposers?
Because they facilitate the breakdown of dead organic material.
What is nutrient cycling and why is it imperative?
The process by which inorganic nutrients are maintained.
Imperative because the supply of inorganic nutrients on Earth (like chemical elements) is finite.
