module 3 Flashcards

Question

3 ways of measuring efficiency of energy transfer

Answer 1

pyramids of biomass pyramids of energy productivity

Answer 2

area of the bars is proportional to the dry mass of all organisms at that trophic level

Answer 3

put organisms in an oven at 80 degrees celcius until all the water in them has evaporated or measure the wet mass of the organisms and calculate the dry mass on the basis of previously published data

Answer 4

burning the organism in a colorimeter and working out how much heat energy is released per gram - this is calculated from the temperature rise of a known mass of water

Answer 5

different species release different amounts of energy per unit mass

Answer 6

only take a snapshot of an ecosystem at one moment in time because pop size varies over time, it can give a distorted idea of the efficiency of energy transfer

Answer 7

the rate at which energy flows through each trophic level

Answer 8

gives an idea of amount of energy available at each trophic level, per unit area, at a given time. usually measure in kilojoules or megajoules of energy per square metre per year at the base of the food chain, productivity of plants is called primary productivity gross primary productivity is the rate at which plants convert light energy into chemical energy the remaining energy (because some was lost due to respiration etc) is called the net primary productivity

Answer 9

gross primary productivity is the rate at which plants convert light energy into chemical energy the remaining energy (because some was lost due to respiration etc) is called the net primary productivity

Answer 10

A directional change in a community of organisms over time

Answer 11

Any change in a community of organisms can cause a change in their habitat Any change in a habitat can also cause a change in the make up of a community

Answer 12

Primary succession

Answer 13

Algae and lichens begin to live on the bare rock. This is the pioneer community Erosion of the Rock and a build up of dead and rotten organisms produces enough soil for larger plants like mosses and ferns to grow. These succeed/replace the algae and lichens Larger plants repkace/succeed smaller plants until a final, stable community is reached. This is called a climax community (woodland communities in the uk)

Answer 14

The algae or lichens that first inhabit bare rock

Answer 15

The final stages of the primary succession

Answer 16

Pioneer plants colonise the sand just above the high water mark. These can tolerate salt water sprat, lack of fresh water and unstable sand Windblown sand builds up around the base of these plants forming a mini sand dune As plants due and decay nutrients accumulate in this mini dune so the dune gets bigger. Plants like sea Sandwood and sea couch grass colonise it.this helps stabilise the sand cz of the underground stems With more stability and nutrients, plants like sea purge and marram grass start to grow. Marram grass helps trap mor wind Other plants colonise the sand as sand and nutrients build up. Bacteria convert nitrogen intro nitrates more species colonise the dunes. This stabilises them further

Answer 17

Saprotrophically | Saprotrophic

Answer 18

Secrete enzymes onto dead and waste material These enzymes digest the ma trial into small molecules, which are then absorbed into the organisms body The molecules are then stored or repaired to release energy

Answer 19

Energy and valuable nutrients would remind trapped within the dead organisms

Answer 20

To make proteins and nucleic acids

Answer 21

Because it's very unreactive so plants can't use it directly

Answer 22

Ammonium ions nh4+ | Nitrate ions no3-

Answer 23

Lightning strikes Haber process Nitrogen fixing bacteria

module 3 Flashcards

(48 cards)