Energy transfers in and between organisms- BP

Question 1

What is the source of energy for an ecosystem?

Answer 1

sunlight

Question 2

what is a consumer?

Answer 2

• animals
• cannot make their own biological molecules
• need to eat plants (primary consumers) or other animals (secondary/tertiary consumers) to obtain biological molecules

Question 3

decomposers?

Answer 3

• bacteria and fungi
• perform saprobiotic decomposition
• release enzyme onto dead plants/dead animals/animal waste (organic matter) breaking them down to obtain biological molecules

Question 4

producers?

Answer 4

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

Question 5

Why do producers (plants) need biological molecules?

Answer 5

 Glucose = respiration, store as starch, make cellulose
 Amino Acids = make proteins e.g. enzymes
 Fatty Acid & Glycerol = make triglyceride as energy store, make phospholipid for membranes

Question 6

Why do consumers (animals) need biological molecules?

Answer 6

 Glucose = respiration, store as glycogen
 Amino Acids = make proteins e.g. enzymes
 Fatty Acid & Glycerol = make triglyceride as energy store and insulation/protection, make phospholipid for membranes

Question 7

Why do decomposers (bacteria/fungi) need biological molecules?

Answer 7

 Glucose = respiration
 Amino Acids = make proteins e.g. enzymes
 Fatty Acid & Glycerol = make phospholipid for membranes

Question 8

How do organisms carry energy?

Answer 8

 Main Source = Glucose
 Stored as Starch in plants and Glycogen in animals
 Alternative Source = Lipids/Fats/Triglycerides and Proteins

Question 9

How does energy move through an ecosystem?

Answer 9

by the food chain, begin with producer and then moves onto primary consumer, then secondary consumer, then tertiary consumer – with decomposers occurring at each stage (trophic level)

Question 10

Why is all the light energy not utilised by plants in photosynthesis?

Answer 10

only 2% is used in photosynthesis – of the rest, a certain part misses the chloroplast, the other parts would be reflected or the wrong wavelength

Question 11

Why is energy lost along a food chain?

Answer 11

• not all of the organism is eaten
• not all is digested (lost in faeces)
• some lost in excretory materials (eg. urine)
• heat loss to the environment

Question 12

Effect of energy loss on a food chain?

Answer 12

• places a limit on the length of a food chain
• those at the higher trophic levels (just quaternary consumers) would not obtain enough energy from the food it consumes

Question 13

What is Productivity?

Answer 13

Amount of Glucose/Energy available to organism

Question 14

What does a Pyramid of Number represent?

Answer 14

• number of each type of organism at each trophic level
• the numbers decrease as we move up trophic levels due to the loss of energy (not as many individuals can be supported)
• can look inverted when it does not take into account mass (e.g. 1 oak tree or millions of fleas)

Question 15

What does a Pyramid of Biomass represent?

Answer 15

 biomass of each type of organism at each trophic level
 biomass = mass of living tissue (based on dry mass, water excluded)
 biomass includes biological molecules, organelles, cells, tissues, organs
 units for biomass (g per m2 for land based animals, g per m3 for water based animals)
 so as we move along a food chain (up trophic levels) there is a loss of energy due to respiration/inedible parts/indigestible parts, so there is less energy to build biomass, so biomass decreases

Question 16

What does a Pyramid of Energy represent?

Answer 16

 amount of energy found at each trophic level
 as before, loss of energy occurs along a food chain (respiration, inedible parts, indigestible parts)

Question 17

What are the units for energy?

Answer 17

kJ/m2 /year

Question 18

how to calculate efficiency?

Answer 18

(energy available after/energy available before)x100

Question 19

what measures may farmers take to improve the energy-conversion rate in the animals they rear?

Answer 19

• limiting movement
• heating the environment around the animals
• controlling feed
• remove predators and pests

Question 20

net productivity equation?

Answer 20

Net Productivity = Gross Productivity – Respiratory [and Faeces] Losses

Question 21

What is net secondary productivity

Answer 21

amount of glucose stored as glycogen after respiration

Question 22

What is gross primary productivity?

Answer 22

amount of glucose made by plant in photosynthesis

Question 23

What is net primary productivity?

Answer 23

amount of glucose stored as starch after respiration

Question 24

What is gross secondary productivity?

Answer 24

amount of glucose consumed by animal

Question 25

what is primary productivity?

Answer 25

Amount of Glucose/Energy available in Plants

Question 26

what is secondary productivity?

Answer 26

Amount of Glucose/Energy available in Animals

Question 27

what is a natural fertiliser?

Answer 27

- consists of the dead and decaying remains of plants and animals as well as animal wastes - eg. manure, slurry and bone meal

Question 28

what is an artificial fertiliser?

Answer 28

mined from rocks and deposits to give an appropriate balance of minerals for a particular crop

Question 29

how do fertilisers incrase productivity?

Answer 29

- ensure nutrients are readily available to crops - means the crops are likely to develop earlier, grow taller and have a larger leaf area - this increasers the rate of photosynthesis - which in turn increases crop productivity

Question 30

what are the environmental affects of using nitrogen-containing fertilisers?

Answer 30

- reduced species diversity - favours the growth of some plants, these outcompete other species, the other species die out - leaching- leads to pollution of watercourses - eutrophication- caused by leaching of fertiliser onto watercourses

Question 31

What is leaching?

Answer 31

the process by which nutrients are removed from the soil

Question 32

What is eutrophication?

Answer 32

the process by which nutrient concentrations increase in bodies of water