Week 7: Energy transfers and Nutrient cycles

Question 1

Nutrients that are required for the organism to survive are also known as

Answer 1

Matter (matter takes up space yeet)

Question 2

Why is energy important?

Answer 2

So organisms can move, synthesise important molecules, maintain a stable internal environment, fight disease and reproduce.

Question 3

What moves matter?

Answer 3

energy

Question 4

What is the primary source of energy for most ecosystems?

Answer 4

The sun

Question 5

In some extreme environments energy can be obtained from

Answer 5

chemical reactions that occur within the ecosystem (e.g. from volcanic eruptions)

Question 6

food chain

Answer 6

diagram showing organisms feeding on each other

Question 7

Ecological efficiency

Answer 7

measure of the percentage of energy that is transferred from one trophic level to the next.

Question 8

Why loss of energy and the transfer being only 10-20% max?

Answer 8

energy used to build and repair body cells, for movement and processes such as generating heat to keep warm and heat being released into environment from organism

Question 9

How much energy available to plants is stored as organic matter through photosynthesis?

Answer 9

1-3%

Question 10

Ecological pyramids can be used to show

Answer 10

energy losses along a food chain at each trophic level

Question 11

Energy is measured in

Answer 11

joules

Question 12

Why are cycles like phosphorus, carbon, nitrogen and water called biogeochemical cycles?

Answer 12

They utilise biological, geological and chemical processes

Question 13

The water cycle describes the

Answer 13

continuous movement of water between different reservoirs and storage locations.

Question 14

Evaporation

Answer 14

heat makes liquid water turn into gas

Question 15

Transpiration

Answer 15

When water evaporates through leaves of plants (also known as evapotranspiration)

Question 16

Condensation

Answer 16

When water vapour cools down to form droplets again

Question 17

Precipitation

Answer 17

When water droplets are large enough to fall in the form of rain snow fleet hail

Question 18

Infiltration

Answer 18

When water infiltrates the ground and soils to collect underground in aquifers

Question 19

Run off

Answer 19

when ground is unable to absorb water, runs off down hills to form bodies of water

Question 20

Root uptakes

Answer 20

When plants absorb water from the soil to their roots

Question 21

key ingredient of all living tissue

Answer 21

carbon

Question 22

Biological processes like decomposition photosynthesis and respiration take up and release

Answer 22

carbon

Question 23

Geochemical processes

Answer 23

release carbon into the atmosphere and oceans through processes like erosion and volcanic eruption

Question 24

4 main processes that move carbon through cycle are

Answer 24

biological- photosynthesis respiration + decomposition
geochemical - erosion and volcanic activity
mixed biogeochemical-burial and decomposition

Question 25

Use of nitrogen

Answer 25

to make amino acids, proteins, chlorophyll, nucleic acids (DNA + RNA) and ATP in cells

Question 26

The only way plants and animals can obtain nitrogen is when its in a

Answer 26

fixed soluble form

Question 27

molecular nitrogen fixed by

Answer 27

atmospheric events and bacteria that are found in soils.

Question 28

Nitrogen Fixation

Answer 28

Nitrogen fixing bacteria are found in soils near roots. | They have enzymes that convert molecular nitrogen into ammonia (NH3) in soils.

Question 29

Nitrification

Answer 29

Nitrifying bacteria convert toxic ammonia (NH3) into nitrates (NO3-) which is now ‘fixed’ nitrogen that is available to plants and animals.

Question 30

Denitrification

Answer 30

Denitrifying bacteria convert nitrates back into molecular nitrogen

Question 31

What plants have nitrogen fixing bacteria inside nodules on their roots?

Answer 31

legumes (peas, beans, lentils, etc)

Question 32

Bacteria and fungi can decompose dead and decaying material back into

Answer 32

ammonium compounds which are also available to plants.

Question 33

Production of phosphorus for

Answer 33

nucleic acids (DNA and RNA), ATP and phospholipids (which are used to form cellular membranes). Phosphorus is released when the substances containing them are eroded by abiotic factors to form Phosphates

Question 34

Phosphorus found in

Answer 34

Rocks, seawater and soils.

Question 35

Phosphorus released when

Answer 35

substances containing them are eroded by abiotic factors to form Phosphates

Question 36

Some plants have a mutualistic relationship with

Answer 36

mycorrhiza fungi - that make phosphorus available to plants.

Question 37

Plants absorb the phosphates and incorporate them into their

Answer 37

tissues

Question 38

How do animals obtain phosphorus?

Answer 38

by consuming plants and other animals

Question 39

Phosphorus returns to the soil when

Answer 39

organisms die

Question 40

How has human activity changed the water cycle?

Answer 40

Removing large quantities of water from rivers for irrigation (e.g. River Murray) Releasing pollutants which enter waterways, directly or indirectly Deforestation where trees normally release water vapour into the atmosphere – decreases water available for precipitation Increasing atmospheric temperatures increases rate of evaporation.

Question 41

How has human activity changed the Phosphorus Cycle?

Answer 41

Run-off in fertilisers can cause overgrowth of some species and loss of biodiversity from the ecosystem. Sewage, including household waste water introduces high levels of phosphorous. Use of fertilisers depletes stores of phosphate in the soils.

Question 42

How has human activity changed the carbon cycle?

Answer 42

The burning of fossil fuels + deforestation has increased atomospheric CO2