Unit 5C: Energy And Ecosystems

Question 1

What are producers

Answer 1

Photosynthetic organisms, manufacturing organic molecules from light, CO2 and minerals

Question 2

What are consumers

Answer 2

Feed on other organisms to obtain energy rather than using energy directly from light

Question 3

Primary, secondary, tertiary consumer definitions

Answer 3

• Primary feed on plants (producers)
• Secondary feed on primary
• Tertiary feed on secondary

Question 4

What are saprobionta

Answer 4

Decomposers that break down complex materials in an ecosystem, contributing to recycling of substances

Question 5

Sources of energy in ecosystems

Answer 5

• producers make their own food from sunlight
• sunlight is conserved as chemical energy by plants in form of organic molecules
• CO2 in air or water is used to create sugar, and the remainder creates biological molecules

Question 6

Reaction for creating proteins

Answer 6

Glucose + nitrates -> amino acids -> protein

Question 7

What is biomass

Answer 7

• the mass of living materials in a specific area in a specific time
• the amount of chemical energy stored in bonds of molecules

Question 8

How can you measure biomass

Answer 8

• fresh mass is easy to access, but organisms have different amounts of water stored so mass is not accurate
• drying out the organism overcomes this problem, but the organism must be dead

Question 9

Equation of energy release

Answer 9

Amount of energy released = mass of water x SHC of water x change in temp

Question 10

Sun energy percentages and notes

Answer 10

• 1% of light energy is captured by green plants
• 90% reflected back into space
• not all wavelengths of light can be absorbed and used for photosynthesis

Question 11

What is gross primary product

Answer 11

Total amount of chemical energy stored converted from light energy by plants in a given area, in a given time

Question 12

How do you calculate net primary product

Answer 12

NPP = gross primary product - respiratory loss

Question 13

Increasing farming efficiency

Answer 13

• farming practicies can increase the efficiency of energy transfer by increasing NPP of crops and NP of livestock
• they can reduce energy loss by: simplifying food webs, biological controls, herbicides, limiting respiration

Question 14

What are trophic levels

Answer 14

• the feeding levels within an ecosystem, can be represented by numbers

Question 15

Net primary production is available for:

Answer 15

• plant growth and reproduction
• available to other trophic levels

Question 16

Reasons for low % energy transfers

Answer 16

• some of the organism is not confused
• lost in faeces
• lost in other excretory products
• energy losses occur as heat from respiration

Question 17

Net productivity equation

Answer 17

Net productivity = energy available in ingested food - (fecal loss + respiratory loss)

Question 18

Microorganisms roles in nutrient cycles

Answer 18

• feed on the remains of dead plants and animals, and their waste products, breaking them sown
• secrete enzymes and digest their food externally, then absorb the nutrients they need
• known as saprobiotic nutrition

Question 19

What are micorrhizae

Answer 19

• symbiotic relationship of fungi and plant roots
• fungi are made or long strands of hyphae, which connect to filament roots
• increase plant roots surface area allowing for more uptake of mineral ions and nutrients

Question 20

Overarching nutrient cycle of decomposers

Answer 20

Inorganic molecule or ion -> (absorption) -> organic molecules in producers -> (feeding and digestion) -> organic molecules in saprobionts (death) -> (decomposition) -> inorganic molecule or ion