Ecosystems

Question 1

what Is a community?

Answer 1

all the populations of different organisms that live together in the same habitat

Question 2

what is an ecosystem?

Answer 2

a community and the habitat in which it lives

Question 3

what is a habitat?

Answer 3

an area which an organism lives

Question 4

what is a population?

Answer 4

all members of a single species that live in the same habitat

Question 5

whats interspecific competition?

Answer 5

competition between two different species

Question 6

what is intraspecific competition?

Answer 6

competition between the same species

Question 7

what is biotic factors? name an example?

Answer 7

interactions between organisms that are LIVING
ie: bacteria can be included

Question 8

list 5 abiotic factors?

Answer 8

light
temperature
water availability
oxygen availability
edaphic (soil) factors
salinity

Question 9

what is abiotic factors?

Answer 9

non-living

Question 10

list biotic factors

Answer 10

grazing
food availability
symbiosis (close and long term interaction between two different species)
disease
competition

Question 11

why are ecosystems described as dynamic?

Answer 11

constantly changing environment and climate

Question 12

Explain why abiotic factors may have a bigger effect on plant species than on animal species in an ecosystem.

Answer 12

Plants cannot relocate themselves to a different, more suitable habitat.

Question 13

where does energy come from in the food chain? explain the process

Answer 13

1. grass is a producer eaten by primary consumer
2. energy enters the ecosystem by procurers
3. the grass converts light energy from the sun into chemical energy during photosynthesis

Question 14

how does energy enter an ecosystem?

Answer 14

through a producer

Question 15

when energy enters a food chain through a producer via sunlight , what is this energy stored as in a plant?

Answer 15

biomass (organic material)

Question 16

how does energy move from the producer to other members of the food chain?

Answer 16

energy transferred to the primary consumer when they eat the producer ie: grass

Question 17

why isn’t 100% of the biomass transferred to the primary, secondary producer etc?

Answer 17

energy is also used for other body actions like respiration (growth and warmth) and excretion

Question 18

in what form is energy always lost when being transferred during the food chain?

Answer 18

lost through heat

Question 19

what is the equation for calculating efficiency?

Answer 19

efficiency = (biomass transfer / biomass intake) x 100

Question 20

A blackberry bush with a mass of 35kg is fed upon by aphids with a collective mass of 4.1kg. Calculate the percentage efficiency of energy transfer in this step of the food chain.

Answer 20

Efficiency = (4.1 ÷ 35) x 100
Efficiency = 11.7%

Question 21

how to calculate the net productivity of PRODUCERS?

Answer 21

NetPrimaryProductivity = gross primary productivity - respiratory losses

Question 22

how to calculate productivity of CONSUMERS

Answer 22

net productivity = energy intake - (loss of excretion + respiratory losses)

Question 23

what is nitrogen fixation?

Answer 23

when nitrogen gas in the atmosphere converts into ammonium by bacteria

Question 24

what bacteria converts nitrogen gas into ammonium in nitrogen fixation?

Answer 24

rhizobium and azotobacter

Question 25

Rhizobium is a bacteria involved in nitrogen fixation, where would this bacteria be found in plants and what do they do?

Answer 25

1. found in the root nodules of legume plants 2. provide pant with nitrogen compounds (used to make proteins)

Question 26

what does the plant provide the bacteria rhizobium with? what biological molecule?

Answer 26

carbohydrates

Question 27

what is ammonification?

Answer 27

when nitrogen compounds from dead organisms are converted into ammonium by decomposers

Question 28

what happens during nitrification?

Answer 28

ammonium ions in the soil are converted into nitrates and nitrites used by the plant

Question 29

during nitrification, bacteria is converted into another molecule, what happens? 1. what bacteria is used ? 2. what does the bacteria convert into?

Answer 29

1. nitrosomonas bacteria -> convert ammonium into nitrites 2. Nitrobacter bacteria -> converts nitrites into nitrates

Question 30

what does the bacteria nitrosomonas do? what part of the carbon cycle is this involved in?

Answer 30

converts ammonium into nitrites involved in nitrification

Question 31

what does nitrobacter convert into? what part of the nitrogen cycle is this used in?

Answer 31

converts nitrites into nitrates part of nitrification

Question 32

what is denitrification?

Answer 32

when nitrites and nitrates in soil converted into nitrogen gas by denitrifying bacteria

Question 33

where does denitrification tend to happen?

Answer 33

in waterlogged soils

Question 34

what happens during denitrification?

Answer 34

creates an anaerobic condition as gentrifying bacteria use nitrates in the soil for anaerobic respiration which produced nitrogen gas

Question 35

what is a haber process?

Answer 35

when nitrogen from the air is reacted with hydrogen to form ammonia and this is used ti produce industrial fertilisers

Question 36

in order what are the steps to nitrogen cycle

Answer 36

1. nitrogen fixation 2. ammonification 3. nitrification 4. denitrification