ecology

Question 1

what is an ecosystem?

Answer 1

interaction of a community of living organisms with the non-living parts of the environment

Question 2

give 4 examples of abiotic factors:

Answer 2

-moisture level
-light intensity
-temperature
-carbon dioxide level (for plants)
-wind intensity and direction
-oxygen level (for aquatic animals)
-soil pH and mineral content

Question 3

give 4 biotic factors:

Answer 3

-new predators
-competition
-new pathogens
-availability of food

Question 4

state adaptation an arctic seal may exhibit:

Answer 4

-white fur, camouflage
-rounded shape, store of fat.
and low surface area to volume to retain heat

Question 5

examples of functional adaptations:

Answer 5

-metabolism
-reproductive system

Question 6

how do camels conserve water supply:

Answer 6

-produce little sweat
-small amounts of concentrated urine
-accumulate fat in their humps, can break down later for water

Question 7

describe how brown bears are adapted to their environment: [6]
-lives in northern latitudes (cold)
-diverse diet including plants, fish, invertebrates, fungi and mammals like deer

Answer 7

-structural
thick fur, conserve heat
long sharp claws to catch fish
lots of muscle to bring down strong mammals
-behavioural
adapted to eat range of food to survive
-functional
when hibernating, metabolism goes down to conserve energy

Question 8

define extremophile:

Answer 8

microorganisms adapted to live in extreme condition such as archaea and bacteria

Question 9

give examples of extremophiles locations:

Answer 9

-high salt con salt lakes
-high pressure deep sea vents
-high temps, hot springs

Question 10

what is transpiration?

Answer 10

evaporation of water from plants

Question 11

5 places where co2 is stored:

Answer 11

-in the air
-in the soil
-in plants’ biological molecules
-in fossil fuels
-in animals’ bio molecules

Question 12

two groups of organisms that carry out decomposition:

Answer 12

-detritivores
small animals like worms and woodlice

-decomposers
microorganisms, such as bacteria and fungi

Question 13

4 factors that affect decay:

Answer 13

-o2 availability
-temperature
higher temp, +kinetic, enzymes closer to optimum temp, +rate of reactions
-water content
conditions need to be moist for decomp to happen, but if too much water not enough o2
-number of decay orgs

Question 14

what is biogas?

Answer 14

-anaerobic decay produces mix of gases called biogas inc methane
-when methane burned releases lot of energy, can be used for electr, etc

Question 15

what is a biogas generator?
-containers
-decay
-use in fields

Answer 15

large containers where animal or plant waste left to decay anaerobically.
there cannot be any oxygen in the container.
else, the microorgs will respire aerobically and won’t prod a lot methane

when biogas removed from tank, sludgy material left over,
contains high density of useful minerals,
can be spread on fields like fertiliser

Question 16

reasons why deforestation occurs:

Answer 16

-growing cattle (farming)
-growing food for cattle
-growing crops for biofuel
-for the wood (logging)

Question 17

main problems of deforestation:

Answer 17

-trees won’t be there to photosynthesize and take in co2
contributes to global warming
-trees removed through burning, release co2, huge plumes of suffocating, polluting smoke
-the habitat and large biodiversity destroyed
-species extinct

Question 18

what are peat bogs?
-conditions
-organisms
-plants

Answer 18

-areas of land where water is acidic and waterlogged
-decay microorgs can’t survive (bcs too acidic, water stops air getting in soil)
-partially rotten plants in the bogs store the co2 instead of emitting it (reduces glo war)

Question 19

what is the disadvantage of removing peat bogs?

Answer 19

-water removed; oxygen gets back in the soil, decay microorgs can come back and decay plants which let out co2
-reduces biodiversity

Question 20

what are top carnivores called?

Answer 20

apex predators

Question 21

what are omnivores?

Answer 21

eat producers and other animals

Question 22

what is the role of decomposers and detritivores?

Answer 22

recycle nutrients from animals and plants back into the ground so they can be used again by plants

Question 23

uses of land:

Answer 23

quarrying, building, farming, dumping waste

Question 24

reasons why only 10% of energy gets passed up biomass:

Answer 24

-not every part of org gets eaten

-bits they do eat may not be absorbed
egested as faeces

-most of nutrients animals absorb used to release energy thru resp; biomass released as waste prod: co2, urea

Question 25

how to calculate efficiency of biomass transfer:

Answer 25

(biom trans to next level / biom available at previous level) x 100

Question 26

factors affecting food security:
-diet
-pathogens
-glo war
-$$$

Answer 26

-diet changes as countries becoming wealthier, inefficient meat consumption

-new pests and pathogens can kill crops nd animals: famine

-environmental changes due to climate change can decrease food yields

-agriculture costs: fuels, fertilizer, expensive, food becomes expensive

Question 27

why has the food that we eat become more intensive to produce?
-diets
-more what now

Answer 27

-diets have changed to incl food that require more land and resources to prod
-ex. we consume more meat than grains

Question 28

GMOs. Improved traits include:

Answer 28

Drought resistance
Increased yield
Herbicide tolerance
Virus resistance
Production of specific proteins (e.g. insulin)
Flood resistance

Question 29

what is mycoprotein?

Answer 29

-protein made by fungi - can be used to make high protein meat subs for veg meals.
-made by fungus fusarium, grown in aerobic conditions on glucose syrup

Question 30

what is sublimation

Answer 30

Sublimation is the change of state from a solid to a gas, without passing through the liquid state.

Question 31

what is deposition

Answer 31

Deposition is the change of state from a gas to a solid.

Question 32

practical to investigate decay

Answer 32

-get a test tube labelled ‘lipase’ and use a pipette to place 5cm3 of lipase solution into it

• label another test tube ‘milk’ and add 5 drops of the indicator Cresol red
• add 5cm of milk and 7cm of the sodium carbonate solution to the milk test tube (purple solution bcs sod car is alkaline)
• place a thermometer into the milk and place the test tube into a beaker of water at first chosen temperature
• wait until temperature of milk is the same as the beaker
• use a pipette to transfer 1cm of lipase solution to the test tube containing milk and stir the solution, start a timer
• at this point the lipase will start to breakdown fat molecules in the milk and release fatty acids which will make the milk become acidic, (now yellow, stop timer)
• repeat in a range of different temperatures

Question 33

Suggest two reasons why the different types of milk took different lengths of time to reach pH 5.

Answer 33

any two from:
* different concentration / type of fat / lipid
* different concentration / type of proteins / carbohydrate /sugar
* different (amount / type of) bacteria present
* different starting pH

Question 34

Farming techniques have changed in recent years.
Describe:
* why more land is being used for farming
* how increased farming has decreased biodiversity

Answer 34

human land use
* increasing population requires more food
* crops / livestock for food
* farming crops for biofuels
* peat use as compost
* peat use as fuel
* increased use of pesticide / insecticide/ herbicide / fertilisers
* use of free-range / organic methods increases land use (for same yield)

link to biodiversity
* deforestation
* monocultures
* loss of hedgerows (to make fields larger)
* loss of habitat
* consequence of loss of habitat eg (change in) migration
* fertiliser run off polluting water
* use of pesticide / insecticide / herbicide reduces insects / plants which damages food chains
* more soil erosion

link to atmospheric pollution
* more carbon dioxide (from farm animals / machinery)
* more methane (from cows)
* climate change or global warming
* example of impact on biodiversity
* acid rain
* desertification