Ecology P2

Question 1

what equipment is used for assessing ecosystems?

Answer 1

quadrats - square frames used for estimating population sizes.
transects -lengths of tape stretched across a habitat to investigate the effect of a factor on a species’ distribution.

Question 2

total population size equation

Answer 2

total area/total sampled x number of organisms counted

Question 3

apex predator

Answer 3

The predator at the top of a food chain.

Question 4

primary/secondary/tertiary consumers

Answer 4

Feed on other organisms for their energy.
P- 1st
S- 2nd
T- 3rd

Question 5

producer

Answer 5

Converts the sun’s energy into useful compounds through photosynthesis (grass).

Question 6

stable community

Answer 6

Where all abiotic and biotic factors are balanced

Question 7

what may species depend on each other for?

Answer 7

• food
• shelter
• pollination
• seed dispersal

Question 8

interdependence

Answer 8

The interaction between two or more organisms where it is mutually beneficial.

Question 9

ecosystem

Answer 9

An area made up of living (biotic) organisms and nonliving (abiotic) parts.

Question 10

individuals

Answer 10

a single member of a species

Question 11

what do animals compete for + why?

Answer 11

• food = provides energy for animals for growth and reproduction
• mates = to reproduce and pass on their genes
• territory = an area of habitat which provides animals with factors like water, shelter, food and mates

Question 12

what do plants compete for + why?

Answer 12

• water = essential for photosynthesis and plant growth
• space = space above soil (so leaves can absorb maximum sunlight) and below soil ( so roots can absorb minerals and ions)
• light = needed for photosynthesis to make glucose which provides energy for growth
• minerals and ions = such as magnesium ions to make chlorophyll and nitrate ions to make proteins

Question 13

populations

Answer 13

Groups of individuals that make up a single species.

Question 14

community

Answer 14

multiple populations (different species) living and interacting in the same area

Question 15

extremophiles

Answer 15

Any organism that likes living in extreme environments.

Question 16

what does the arrow mean in a food chain/web.

Answer 16

Indicates where the energy is going.

Question 17

Interspecific vs Intraspecific

Answer 17

Inter—> competition between different species (internet is world wide)
Intra—> competition within the same species

Question 18

Respiration chemical/word equation

Answer 18

glucose + oxygen —> carbon dioxide + water

C6H12O6 + 6O2 —> 6CO2 + 6H2O

Question 19

2 Resources humans are using up?

Answer 19

• finite reserves of metal ores

- non-renewable energy resources (crude oil/ natural gases)

Question 20

Food security

Answer 20

Having enough food to feed a population

Question 21

How do humans pollute the land?

Answer 21

• human waste in soil causes parasites and chemicals
• farming increases CO2 emissions
• household waste in landfills means chemicals are spread into soil

Question 22

How do humans pollute the sea?

Answer 22

• minerals and fertilisers are washed from soil into local streams, ponds and rivers.
• untreated sewage that is washed into waterways/pumped into seas —> causes high levels of NITRATE in water

Question 23

Pros + Cons of breeding programmes for endangered species

Answer 23

Pros-

• increase in numbers
• prevents extinction

Cons-

• inbreeding
• can’t always be re interduced (to wild)

Question 24

Eutrophication

Answer 24

Fertilisers which run off into lakes in surface water runoffs, causing a dense plant growth

Question 25

Negative consequences of increasing farming?

Answer 25

- genetic modification - pollution - greenhouse gases - increase in pests and pathogens - increase in fertilisers - deforestation - extinctions of overfishing

Question 26

Bioaccumualtion

Answer 26

Accumulation of chemicals in an organism that takes place if the rate of intake exceeds the rate of excretion.

Question 27

The Carbon Cycle key points

Answer 27

Carbon dioxide in atmosphere, enters via photosynthesis | Carbon dioxide returns to atmosphere by aerobic respiration

Question 28

The Carbon Cycle

Answer 28

1) Carbon dioxide in atmosphere through respiration of plants, algae, animals, decomposing microorganisms and combustion of fossil fuels. 2) Carbon dioxide taken from atmosphere via photosynthesis of plants and algae. 3) This carbon transferred through feeding of animals, then more animals (they respire, back into atmosphere). 4) When they die, decomposing microorganisms feed and then respire (carbon back into atmosphere). 5) Through a lack of oxygen, decomposers cannot work effectively meaning carbon in remains turns into fossil fuels, which humans burn (combustion of fossil fuels from dead remains brings carbon back into atmosphere)

Question 29

Why are decomposing microorganisms important (TCC)

Answer 29

- They cycle materials through an ecosystem - Return carbon to atmosphere as carbon dioxide - Release mineral ions to the soil

Question 30

What happens if there is a lack of oxygen for decomposers (TCC)

Answer 30

decomposers cannot work effectively, leading to the carbon in dead remains to convert into fossil fuels Decomposing microorganisms carry out anaerobic decay. Anaerobic decay produces methane (greenhouse gas) = this is called biogas

Question 31

The Water Cycle

Answer 31

1) Energy from sun causes water to evaporate from the surface of the sea. The water vapour travels into the air and cools down. 2) When it cools, the water vapour condenses to form clouds. 3) Water in clouds falls to ground as precipitation (rain, snow, sleet and hail) = all forms of precipitation contain fresh water/ NO SALT 4) Once water hits the ground, some of it evaporates back into out atmosphere as water vapour. 5) Some of the water passes through rocks and forms aquifers. 6) A lot of the water forms rivers/streams which eventually drain back into our sea.

Question 32

Aquifers

Answer 32

A body of permeable rock which contains/transmits groundwater (the water cycle)

Question 33

Is water abiotic/biotic factor?

Answer 33

water is an abiotic factor (non-living) which effects communities

Question 34

Living organisms contribution to the water cycle

Answer 34

- plants take up water in roots ( moves up the plain in the xylem, passing out through leaves in the stomata as water vapour) = aka transpiration - animals take in water through drinking and in foods (animals release water through urine, faeces and exhalation)

Question 35

Transpiration

Answer 35

(of a plant or leaf) the exhalation of water vapour through the stomata.

Question 36

examples of decomposing microorganisms

Answer 36

bacteria | fungi

Question 37

Conditions needed for decomposition

Answer 37

- temperature - amount of water - amount of oxygen

Question 38

decomposition (temperature)

Answer 38

Faster at warmer temperatures as decomposers use enzymes to breakdown the plant materials as these enzymes work faster in warm conditions. Compost heaps of warm as the decomposers release energy through aerobic respiration. You do not want to get too hot as enzymes and decomposers can denature and die

Question 39

decomposition (amount of water)

Answer 39

Faster if compost is moist as chemical reactions in decay require water. DO NOT let compost dry out.

Question 40

decomposition (amount of oxygen) - what is done in farming to help?

Answer 40

Decomposers carry out aerobic respiration (requires a good supply of oxygen). - Compost bins have holes in for oxygen to enter - Gardening forks to mix = more oxygen to pass through centre, breaks up large clumps increasing surface area for decomposers to act on.

Question 41

What happens if there is no oxygen (decomposition)

Answer 41

Decomposing microorganisms carry out anaerobic decay. | Anaerobic decay produces methane (greenhouse gas) = this is called biogas

Question 42

Biogas

Answer 42

Anaerobic decay producing methane from fermentation of organic matter.

Question 43

biotic and abiotic meaning

Answer 43

biotic - living factors | abiotic - non-living factors = effecting an environment

Question 44

RP 9 - sampling organisms | Estimate the total population of daisies in a field

Answer 44

1) First place two tape measures at right angles. These should be 20m in length. 2) Get two bags containing the numbers 1 to 20 , should be in groups of three. 3) Student 1 picks a number at random and stands at the number in meters on the tape measure (student 2 does the same along other tape measure). 4) Student 2 places a quadrat where the two points meet (like a graph, along x up y). 5) Students record the number of daisies in first quadrat. 6) Return number to bag and repeat 9 more times (10 in total). 7) Estimate the total population size of daisies using this equation total area/area sampled x number counted of daisies - if you think 10 is not representative of population, increase number of quadrats to cover a greater percentage of area -> increases validity

Question 45

RP 9 - sampling organisms | Measure the effect of light intensity on the distribution of daisies

Answer 45

1) Place a tape measure at the tree. 2) Then use a quadrat to count the number of daisies at the start of the transect. 3) Using a light meter record the light intensity at the same point. 4) Move the quadrat by 1m down the tape measure and repeat measurements all the way down transect. 5) Most likely to see a greater number of daisies as we move further from tree as plants need light for photosynthesis. Also, tree will absorb a lot of water + minerals from soil so it might be that light intensity is not the only abiotic factor affected the distribution of daisies.

Question 46

algal bloom

Answer 46

a rapid increase in the number of plants

Question 47

In eutrophication, what directly causes the death of fish?

Answer 47

bacteria use up oxygen in respiration