Life processes in the biosphere Flashcards
Definition of biome (examples)
a geographical area with a specific climax and a unique community of species (coral reefs/rainforests/deserts)
Name 2 biotic factors which organisms have adapted to (give examples for each both plant and animal)
- Reproduction = pollination:scents to attract insect pollinators, less haphazard than wind pollination
- Food = predators: eyes at front of head, fast, sharp teeth/claws. Prey: eyes at side of head (360 view), camouflaged, enzymes to digest cellulose. Plant defences = thorns, inpalitablity
Name at least 3 of the 6 abiotic factors which organisms have adapted too (examples for each factor)
- Turbulence = strong anchors (roots)
- Low light levels = Plant:large leaf SA, widely dilating pupils
- High temps = thin insulation, elongated extremities to prevent enzymes denaturing
- Low temps = small SA:V ratio, thick fur/blubber, shorter fatter extremities
- water shortage = leaves reduced to needles reduce transpiration loss
- low nutrient levels in soil = nitrogen fixation
definition of range of tolerance
range of conditions (abiotic factors) in which an organism can survive in.
genetic ________ means that the range of _________ to any environmental factor will ____. if the conditions are ________ an organisms range of tolerance it will not ______.
variation, tolerance, vary.
outside, survive
In food webs the direction of arrows show….
the direction of energy
Name at least 3 of the 6 interdependent species relationships
- decomposers and detritivores
- Parasitism
- Symbiosis
- pollination and seed dispersal
- habitat provision/modifying abiotic factors
- feeding relationships
What is the difference between detritivores and decomposers?
detritivores = break down large DOM into smaller pieces (increases SA for decomposers) i.e. starfish, worms, millipedes decomposers = the breakdown of DOM so it recycles it back into soil i.e. nitrogen
what is parasitism? (examples)
a relationship where one species benefits at the expense of another (ticks, fleas, tongue lice)
what is symbiosis? ((examples)
is relationship where both species benefit (birds/fish eat parasites/bacteria on other organisms
What is the difference between pollination and seed dispersal?
pollination = where male and female sex cells in plants are able to meet due to being carried by an organism
seed dispersal = enables seeds to be transported (animal gets food , if seeds in fruit, dispersed in droppings)
What is habitat provision/modifying abiotic factors?
examples
species that modify a habitat and therefore abiotic conditions so new species can develop
i.e. plants produce oxygen, prairie dog burrows can be inhabited by many other species
What does it mean by feeding relationships? (example)
relationship between organisms eating and being eaten . and the knock on effect it has. (canadian lynx and snow hare)
What is the difference between primary and secondary succession?
primary = plant succession from bare rock (no soil) secondary = where the climax community has been disturbed but the soil remains present
definition of climax community?
a relatively stable community at the end of ecological succession
definition for pioneer species (examples)
species that first colonise a barren area, at the start of ecological succession. they are usually well adapted to extreme abiotic factors
Common features of succession:
- ______ factors become ____ hostile
- A greater number and ______ of habitat and therefore _____ sources.
- More complex food ___, leading to increased ______
- change in species ______: new species _______ other species
- Abiotic, less
- variety, food
- webs biomass
- composition, outcompete
Similarities and differences between hydrosere and lithosere succession
Similarities = change in species/community, vegetation and soil depth increases, less hostile abiotic conditions, increase biomass, more variety of food sources and habitat Differences= hydro: water succession, soil moisture decreases. For both hydro and litho they have different species (i.e. water lilies for hydro)
definition of plagioclimax (examples)
when human activity has stopped (deflected) ecological succession. (pollarding, coppicing, ploughing, controlled burning)
Why is there a change in species present in the climax community compared to the species present in the earlier stages of succession?
Habitat loss and competition as a result of succession
how can we conserve habitats in the different stages of succession (and therefore species present)?
preventing changes to the different succession stages through deflected succession (plagioclimax)
What is the difference between coppicing and pollarding?
coppicing = where young tree stems are cut near the base, many trees will regrow from the stump. pollarding = upper branches are cut. Often used to maintain trees at a particular height
The effect of deflected succession on species diversity?
- coppicing and _______ are likely to _______ structural _______.
- Creates new ___________ therefore can support different _____ as habitat will be less _______.
- Reduces effect of ________ species in a _______ community
- Increase __________ to the floor and encourages ______ of floor dwelling vegetation. This in turn attracts _________.
- pollarding, increase, diversity
- microhabitats, niches, uniform
- dominant, climax
- sunlight, growth, pollinators
Definition of population dynamics
changes which affect population
definition of carrying capacity
max. no of individuals that an ecosystem can support sustainably
what is the difference between a density dependant factor (DDF) and a density independent factor (DIF)? (examples for each)
DDF = a factor that has a bigger impact when pop. is high. (availability of food, shelter, disease, predation) DIF = a factor that has the same level of effect on both a small and large pop. (flood, volcanic eruption, soil depth, soil pH, rainfall)
If the pop. size rises ____ carrying _______ then the density _________ factor becomes stronger. Therefore, _______ rate increases and so the pop. ________
above, capacity, dependant, mortality, decreases
definition of R-selected species
species with high growth rates to exploit less crowded niches. Mature at a young age, short gestation period, little investment in offspring, offspring has low survival rate.
examples - rabbits, mice, rats, insects
definition of K-selected species
Species that live at densities close to carrying capacity. Invest heavily in offspring which have a high survival rate. Long gestation period, mature older.
examples - elephants, bison, whales
which species (K or R) are more likely to suffer from overexploitation and why?
K-selected species as they can not reproduce as quickly and therefore cannot increase pop.size .
When might artificial control be necessary? (3 reasons)`
- Introduction on invasive species acts as a competitor
- loss of indigenous predator (prey unregulated)
- when breeding rate of endangered species low, captive breeding needed
what pop. features might be needed when establishing conservation plans?
if it is K or R species. Birth rates. Pop. size. distribution, age structure, survival rates
