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A Level Biology Me > Chaptwr 23 Ecosystems > Flashcards

Chaptwr 23 Ecosystems Flashcards

1
Q

What is ecology?

A

Ecology is name given to the study if the relationships between organisms and their environments

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2
Q

An ecosystem

Sizes of them?

A

Is made up of all the living organisms that interact with one another in a defined area , (biotic), and also all th non living conditions/ factors there (so abiotic)

All the living organisms as well as the biotic factors, and non living conditonsin an area

Ecosystems can vary in size, from it being a tiny bacterial colony to the entire biosphere of earth

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3
Q

Factors affecting ecosystems (what are they all)

A

Abiotic = the non living physical factors like

  • light,
  • temperature,
  • water availability ,
  • oxygen availability ,
  • Edaphic soil factors

And biotic living factors
- competition (food water space mates terroriory’
- predator prey relationships
-

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4
Q

Abiotic factor light effect?

What does high light do to a plant, and low light , and what have plants adapted for

A

Most plants affected by light intensity because light is directly needed for photosynthesis, so the greater the light the greater the succes of plant

  • however plants can cope with different intensities using adaptations
  • low light areas have larger leaves
  • may have photosynthetic pigmented thst require less light
  • only operate when at an optimum
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5
Q

Temoertwure

What is good in high temps
What can changes in temp do

A

Big effect because it effects the enzymes controlling metabolic reactions and thus hoe effienct twn organism csn be

  • plants develop better in warmer temps as well as ectothermic animals
  • also changes in temp can initiate hibernation migration dormancy etc
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6
Q

Water availability

A

Lack of water for most things = stress

  • plants hav adapted to survive for them, cacti
  • as need for photo and hydrostatic skeleton
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7
Q

Oxygen availability

A

Obvs need oxygen to respire and survive

Better to have fast flowing cold water because more concentration of oxygen, if become too war, can suffocate aquatic animals snd plants

Waterlogged soil, spaces between soil filled with oxygen so less available for lkantd, thatswhy specialised arenchyma tissue in hydrophytes come in clutch

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8
Q

Edaphic = soil factors

A

Soil exists in different particle sizes, based on them the organism will have to adapt differently

For example
Clay is essilky waterlogged and forms clumps

Loam (different sized) retains water but does not before waterlogged
Sandy coarse particles allows free draining , so water not retained and soil eroded

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9
Q

Food chains and trophies levels?

What are they

A

Food chains show the transfer of energy in an ecosystem , with different trophies levels

All start from producer which gets energy from sun and converts using photos , then primary consumer eats that secondary and tertiary,

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10
Q

Why do food chains not sustain more than max quaternary consumer

A

Because there is nit ENOUGH BIOMASS and stored energy keft to support life processes for any more organisms

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11
Q

Why are decomposed useful?

A

They break down dead organisms and release nutrientd BACK INTO ecosystem and clear waste

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12
Q

What two ways can food chains be represented in a more groahical like form

A
  • pyramid of numbers

- pyramid of biomass

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13
Q

What is biomass and how to calculate

What DO PYRAMID OF BIOMASS REPRESENT SND WHAT DOES IT JOT TAKE INTO SCCOUNT

A

Is the mass of DRY living material present in a particular place , where energy is stored

Here you need to multiply the biomass (could be an average) of one by all the organisms present in thst level

Then you can put this into a pyramid of biomass

2) they represent biomass present of thst trophies level at a SPECIFIC MOMENT IN TIME , and nit take into account any seasonal changes

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14
Q

Why is pyramid of biomass preferred over number

A

Pyramid of numbers nit necaseikt a pyramid because one organism can have huge mass

As a result pyramid of bikmass is normally a pyramid

But there is an exception for onyplnaktom one because less mass but mroe number

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15
Q

How to messure biomass directly and why

A

Like before had to be dry content because water varies between organisms

Therefore dry mass done by

  • killing organisms
  • placed in a kiln at 80° until all evaporated

As a result only few samples taken to minise this, but then won’t be representative, so a problem

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16
Q

Why is biomass ALWAYS LESS IN THE NEXT TROPHIC LEVEL ALMOST ALWAYS ?

1) why is not all biomass even taken up (plants then animals)
2) what happens to biomass that is taken up

A
  • for plants because it csntuse all the light (wrong wavelength ) + it’s reflected + so,e doesn’t hit the leaves
  • also bones and stalks etc not eaten
  • some parts are indigestible and come out in egestion and excretion

Then what is available biomass converted to energy but not all converted to increasing biomass

  • some is used for respiration for energy in MOVEMENT , and KEEPIMG WARM , respiratory loss,
  • and whatever energy actually left becomes biomass

As a result only about 10% of biomass is actually converted into more biomass

17
Q

What are unite of energy available

Why per year?

A

Assuming energy = biomass

KJ/ M2/ year

Measure dpernyesr to take into account photosynthetic changing patterns in the year

18
Q

What is the effienct synthetics biomass is transferred from one level to the other called

A

Ecological effienct , and shown by pyrsmid of energy

19
Q

Again why is not all energy from sun converted to biomass

What is energy actually fully taken in called, and what is energy used for biomass called

A
  • some reflected, not all csn be absorbed, some don’t hit the leaves
  • photosynthesis can be limited by other factors so energy wasted
  • some of energy used for other photosynthetic reactions + respiration for processes

Energy fully taken in = gross production
But this energy used repsirsiton , remaining into biomass
So energy for biomass = net production

So equation for net production = GROSS PRODUCTION - RESPIRATIORY LOSS A

20
Q

Again terms for energy available to organism, and energy used as biomass and equation

A

Gross production available
Net production biomass

Net production = gross - respiratory

21
Q

What is formula for ecological effeicney (effienct for biomass transfer) then

A

Energy / biomass available after the transfer/ energy available before x100

22
Q

How have human activities affected biomass transfer for their needs

How do make sure trsnsfer of biomass is max

A

By farming , we set optimum conditions for things we want to grow so their biomass is at maximum (most food, shelter protection abiotic condiins ti grow )

And then we limit the transfer to max 3 levels, either cosumer, primary and secondary which is us for meat or just producer and then primary which is us

This way we ensure less biomass is lost and as much energy is transferred and thus Availble for us

23
Q

Does effeicny if energy transfers increase higher trophic levels , why?

A

Yes, osknt start low because sun gives out so much energy so effienct ginsn be low

Then lrinsry ginsn be a bit higher but lower than secondary because plants have more indigestible contents (cellulose) than animals which is probably just boned , so they increase

But stilk deepeneds

24
Q

Why can you use biomass as an indication

A

Because energy is stored as this so you can

25
Q

What is problem with Chuck sting effeicny if biomass transfer why is there more to its

A

Because it’s not guaranteed the consumer ATE ALL OF THE THING BEFORR, probably ate other, so it’s all from one to an other .

26
Q

Why do nutrients have ti be received

A

Sun keeps giving energy so calm, but nothing renews the nutrients so we need recycling and decomposition

27
Q

What is decomposition

A

The process of a compound beign broken down into smaller molecules or elements,

Needed becsude often an essential element like nitorgen csnt be used in its raw form , but rather

28
Q

What are decomposed and detritivores
What do decomposed do and examples and how

Detritivores so and examples

A

Decomposed organism that feeds on dead organic matter snd turning it into inorganic matter which is available for photosynthetic producers . Thy are normally bacteria fungi

They dot his as they are saprotophs, they release digestive enxymes extracuklsrly which digest and then they absorb nutrients

Detritivores are other organisms that feed in DETRITUS, which is basically bigger dead and decaying material and break it down into smaller which increases surface area for decompsoered to work on snd makes porfedd bigger

Detritivores DO INTERNAL

29
Q

What is nitorgen used for in plants

A

As nitrated for making nucleic acids and also amino acids (anything that needs nitrogen ) and thus proteins

A Level Biology Me (41 decks)

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