B4.2 Echological Niches Flashcards
niche
role played by a species in its community which includes its abiotic requirements and tolerance, and its interaction with other organism
influences growth, survival and reproduction of species and how it obtains food
what happens if 2 organisms occupy the same niche
leading to evolutionary process or competitive exclusion
where are principles of niches seen
shag and cormorant - both live and feed along coastline and rear young on cliffs and rocks but have different diets and behaviours - avoid competition from each other
shag
nest on much narrower cliffs
feeds further to sea - fish and eels
cormorants
feeds near to shore
seabed fish - flatfish
why did first organisms on earth breathe with anaerobic respiration
because the earth was less in oxygen and there was nothing to produce it
obligate aerobes examples
mycobacterium tuberculosis -TB
obligate aerobes
organisms that can only respire aerobically - all plants and animals
obligate anaerobes
organisms that only respire in the absence of oxygen
poisoned by presence of oxygen
lack defence mechanisms to protect enzymes from oxidants
obligate anaerobes examples
methane producing archaea
facultative anaerobes
organism that normally respires aerobically but has the facility to switch anaerobic respiration in the absence of oxygen
facultative anaerobes example
E. coli
lives in intestines animals and also water, food, soil
autotrophic
using external energy sources to synthesis glucose from simple inorganic substances
heterotrophic
using carbon compounds obtained from other organisms to synthesise required carbon compounds
photoautotrophs
plants that use sunlight to make food
other organisms contain pigments and are autotrophs
algae, photosynthetic bacteria, cyanobacteria
herbivores
an animal that feeds holozoically exclusively on plants
primary consumers
carnivores
flesh eating organism
secondary consumer
holozoic nutrition
nutrition in consumers where food is ingested, digested internally, absurd and assimilated
animals nutrition
get their nutrition from existing nutrients
- dependant on plant nutrition
- animal is a consumer
- animal nutrition is heterotrophic
mixotrophic
both autotrophic and heterotrophic nutrition
example of mixotropic nutrition organism
marine flatworm
- have algae living symbiotically in body
phytoplankton nutrition
take up dissolved organic carbon under inorganic nutrients stress
osmotrophy
uptake of dissolved organic material
saphrotropic
an organism that lives on or in dead organic matter, secreting digestive enzymes into it and absorbing the products of digestion
examples of saphrotrophs
fungi and bacteria
are decomposers but also carry out heterotrophic nutrition
detrivore
organism that ingests dead organic matter
holozoic nutrition
secrete enzymes and digest food outside body
archaea
domain of microbes