Life processes in the biosphere

Question 1

Definition of biome (examples)

Answer 1

a geographical area with a specific climax and a unique community of species (coral reefs/rainforests/deserts)

Question 2

Name 2 biotic factors which organisms have adapted to (give examples for each both plant and animal)

Answer 2

1. Reproduction = pollination:scents to attract insect pollinators, less haphazard than wind pollination
2. 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

Question 3

Name at least 3 of the 6 abiotic factors which organisms have adapted too (examples for each factor)

Answer 3

1. Turbulence = strong anchors (roots)
2. Low light levels = Plant:large leaf SA, widely dilating pupils
3. High temps = thin insulation, elongated extremities to prevent enzymes denaturing
4. Low temps = small SA:V ratio, thick fur/blubber, shorter fatter extremities
5. water shortage = leaves reduced to needles reduce transpiration loss
6. low nutrient levels in soil = nitrogen fixation

Question 4

definition of range of tolerance

Answer 4

range of conditions (abiotic factors) in which an organism can survive in.

Question 5

genetic ________ means that the range of _________ to any environmental factor will ____. if the conditions are ________ an organisms range of tolerance it will not ______.

Answer 5

variation, tolerance, vary.

outside, survive

Question 6

In food webs the direction of arrows show….

Answer 6

the direction of energy

Question 7

Name at least 3 of the 6 interdependent species relationships

Answer 7

1. decomposers and detritivores
2. Parasitism
3. Symbiosis
4. pollination and seed dispersal
5. habitat provision/modifying abiotic factors
6. feeding relationships

Question 8

What is the difference between detritivores and decomposers?

Answer 8

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

Question 9

what is parasitism? (examples)

Answer 9

a relationship where one species benefits at the expense of another (ticks, fleas, tongue lice)

Question 10

what is symbiosis? ((examples)

Answer 10

is relationship where both species benefit (birds/fish eat parasites/bacteria on other organisms

Question 11

What is the difference between pollination and seed dispersal?

Answer 11

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)

Question 12

What is habitat provision/modifying abiotic factors?

examples

Answer 12

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

Question 13

What does it mean by feeding relationships? (example)

Answer 13

relationship between organisms eating and being eaten . and the knock on effect it has. (canadian lynx and snow hare)

Question 14

What is the difference between primary and secondary succession?

Answer 14

primary = plant succession from bare rock (no soil)
secondary = where the climax community has been disturbed but the soil remains present

Question 15

definition of climax community?

Answer 15

a relatively stable community at the end of ecological succession

Question 16

definition for pioneer species (examples)

Answer 16

species that first colonise a barren area, at the start of ecological succession. they are usually well adapted to extreme abiotic factors

Question 17

Common features of succession:

1. ______ factors become ____ hostile
2. A greater number and ______ of habitat and therefore _____ sources.
3. More complex food ___, leading to increased ______
4. change in species ______: new species _______ other species

Answer 17

1. Abiotic, less
2. variety, food
3. webs biomass
4. composition, outcompete

Question 18

Similarities and differences between hydrosere and lithosere succession

Answer 18

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)

Question 19

definition of plagioclimax (examples)

Answer 19

when human activity has stopped (deflected) ecological succession. (pollarding, coppicing, ploughing, controlled burning)

Question 20

Why is there a change in species present in the climax community compared to the species present in the earlier stages of succession?

Answer 20

Habitat loss and competition as a result of succession

Question 21

how can we conserve habitats in the different stages of succession (and therefore species present)?

Answer 21

preventing changes to the different succession stages through deflected succession (plagioclimax)

Question 22

What is the difference between coppicing and pollarding?

Answer 22

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

Question 23

The effect of deflected succession on species diversity?

1. coppicing and _______ are likely to _______ structural _______.
2. Creates new ___________ therefore can support different _____ as habitat will be less _______.
3. Reduces effect of ________ species in a _______ community
4. Increase __________ to the floor and encourages ______ of floor dwelling vegetation. This in turn attracts _________.

Answer 23

1. pollarding, increase, diversity
2. microhabitats, niches, uniform
3. dominant, climax
4. sunlight, growth, pollinators

Question 24

Definition of population dynamics

Answer 24

changes which affect population

Question 25

definition of carrying capacity

Answer 25

max. no of individuals that an ecosystem can support sustainably

Question 26

what is the difference between a density dependant factor (DDF) and a density independent factor (DIF)? (examples for each)

Answer 26

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)

Question 27

If the pop. size rises ____ carrying _______ then the density _________ factor becomes stronger. Therefore, _______ rate increases and so the pop. ________

Answer 27

above, capacity, dependant, mortality, decreases

Question 28

definition of R-selected species

Answer 28

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

Question 29

definition of K-selected species

Answer 29

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

Question 30

which species (K or R) are more likely to suffer from overexploitation and why?

Answer 30

K-selected species as they can not reproduce as quickly and therefore cannot increase pop.size .

Question 31

When might artificial control be necessary? (3 reasons)`

Answer 31

1. Introduction on invasive species acts as a competitor
2. loss of indigenous predator (prey unregulated)
3. when breeding rate of endangered species low, captive breeding needed

Question 32

what pop. features might be needed when establishing conservation plans?

Answer 32

if it is K or R species. Birth rates. Pop. size. distribution, age structure, survival rates