13 energy and ecosystem

Question 1

what is the simple sequence of nutrient cycles

Answer 1

1. nutrient is taken up by producers as simple inorganic molecules
2. the producer incorporates the nutrients into complex organic molecules
3. when the producer is eaten the nutrients passes into the consumer
4. it then passe along the food chain
5. when the producers and consumers die, their complex molecules are broken down by saprobiontic microorganisms that release the nutrients in its organic simple form

Question 2

what is nitrogen used for

Answer 2

the manufacture of proteins and nucleic acid

Question 3

how do plants gain nitrogen

Answer 3

in the form of nitrate ions (No3-) form the soil through active transport by the roots

Question 4

how do animals gain nitrogen

Answer 4

by eating and digesting plants

Question 5

what are the 4 process involved with the nitrogen cycle

Answer 5

1. ammonification
2. nitrification
3. nitrogen fixation
4. denitrification

Question 6

what is ammonification

Answer 6

• the production if ammonia form organic nitrogen containing compounds (urea, proteins, nucleic acids and vitamins)
• saprobiontic microorganisms feed on faeces and dead organisms materials releasing ammonia which forms ammonia ions in the soil

Question 7

what is nitrification

Answer 7

• oxidation reaction carried out by nitrifiying bacteria that releases energy
  1. oxidation of ammonium ions to nitrate ions(no2-)
  2. oxidation if nitrate ions to nitrate ions (no3-)

Question 8

what is nitrogen fixation

Answer 8

• nitrogen gas is conveted into nitrogen contain compounds
• can be carried out industrially or naturally through lightening passing through the atmosphere
• carried out by free living nitrogen fixing bacteria and mutralistic nitrogen fixing bacteria

Question 9

what are naturalistic nitrogen fixing bacteria

Answer 9

• live in nodules of bean plat roots
• obtain carbohydrates from the plats and the plants acquire amino acid form the bacteria

Question 10

what are organic natural fertilisers

Answer 10

• consist of dead and decaying remains of plant and animals and waster matter

Question 11

what is artificial inorganic fertiliser

Answer 11

• are mined form rocks and blend together to get the appropriate blend of minerals

Question 12

organic components that contain nitrogen

Answer 12

• amino acids
• ATP
• DNA

Question 13

benefits of nitrates to a plant

Answer 13

• develop earlier
• grow taller
• greater leaf area

Question 14

detrimental effects of nitrogen containing fertilisers

Answer 14

• reduces species diversity
• leaching
• eutrophication

Question 15

how does nitrogen fertileser reduce species diversity

Answer 15

• nitrogen rich soil favours fast growing plats like grass and nettle
• other species are then outcompeted so die
• species rich meadows only survive if there are low levels of nitrogen allowing other species to grow

Question 16

what is leeching

Answer 16

• the process nutrients are removed form the soil

Question 17

leeching process

Answer 17

• rainwater dissolves soluble nutrients, carrying them deep into the soil where plant roots cannot reach
• the leached nitrate ions find themselves in rives and stream then drain into freshwater lakes
• may have a harmful effect on human if in drinking water

Question 18

what is eutrophication

Answer 18

the process where nutrient concentration increase in bodies of water

Question 19

process of eutrophication

Answer 19

• naturally low concentration of nitrates in lakes and rivers, making it a limiting factor for plant and algae growth
• leeching lead to an increase in nitrate concentration so it no longer becomes a limiting factor for plant growth
• algae grows on the surface of the water (algae bloom)
• dense layer of algae absorbs light and prevents it form reaching the lower depts
• light becomes a limiting factor for the plants lower down so they die
• saprobiontic bacteria grow using the dead organisms
• the bacteria requires oxygen for respiration so oxygen concentration decreases
• aerobic organism die as they have not oxygen
• anaerobic organisms population rises as they no longer have competition
• anaerobic organism release more nitrate and toxic waste making the water putrid

Question 20

what is the source of energy for all ecosystems

Answer 20

the sun

Question 21

what is gross primary productivity (GPP)

Answer 21

• the total quantity of plant biomass stored in a given area at a given time

Question 22

what is net primary productivity (NPP)

Answer 22

the chemical energy store that is left after the looses of respiration has been taken into account

Question 23

why is there a low percentage of energy transferred at each stage in the tropic levels

Answer 23

1. not all of the organism is consumed
2. some parts are consumed but cannot be digested so lost as faeces
3. some energy is lost in excretory material like urine
4. some energy is lost as heat form respiration

Question 24

what are producers

Answer 24

photosynthetic organism that manufacture organic substances using light energy, water, carbon dioxide and mineral ions

Question 25

what are consumers

Answer 25

• organism that obtain their energy via feeding on other organism

Question 26

what are saprobionts

Answer 26

• organism that break down the complex matter in dead organisms into simple ones

Question 27

what is biomass

Answer 27

the total mass of living material in a specific area art a given time

Question 28

what does a calorimetry do

Answer 28

measures the chemical energy stores on dry mass