C4.2 transfers of energy and matter

Question 1

Two types of energy systems

Answer 1

1. Open (resources can enter and exit, ecosystems), 2. closed (energy can enter or exit but chemical resources cannot be removed or replaced)

Question 2

Producers

Answer 2

Use external energy source to make carbon compounds (photosynthesis - cyanobacteria, plants and eukaryotic algae) (in sealed caves: archaebacteria that gain energy from chemical reactions)

Question 3

Food chain

Answer 3

Producer -> primary consumer -> secondary consumer -> tertiary consumer

Question 4

Saprotrophs

Answer 4

Decomposers feeding on dead organic matter (amino acids, glucose, carbon compounds) for growth and source of energy

Question 5

Autotrophs

Answer 5

Self-feeding using CO2 or hydrogen carbonate + an energy source (inorganic chemical reactions or light)

Question 6

How are autotrophs and heterotrophs dependent

Answer 6

Heterotrophs give autotrophs CO2 from cell respiration, autotrophs give heterotrophs oxygen

Question 7

Heterotrophs

Answer 7

feed on other organisms (saprotrophs digest food externally by hydrolytic enzymes, consumers ingest food)

Question 7

Energy is used by organisms in four processes:

Answer 7

1. anabolic reactions (synthesising molecules e.g. proteins), 2. Active transport for concentration gradients, 3. Movement (of vesicles, of whole organisms, etc.), 4. Maintaining constant body temperature

Question 8

Energy is lost between trophic levels due to what? (3)

Answer 8

1. Incomplete consumption (never consumed organisms just die), 2. Incomplete digestion (e.g. poop), 3. Cell respiration (oxidised carbon compounds cannot pass to next level)

Question 9

Heat loss happens because…

Answer 9

chemical energy is converted to heat in cell respiration which is lost to the abiotic environment

Question 10

Length of food chains is limited due to…

Answer 10

energy loss between trophic levels

Question 11

Primary production – GPP and net primary production

Answer 11

GPP = total production from photosynthesis, NPP = available to consumers

Question 12

Carbon cycle: what contribute to CO2 in atmosphere?

Answer 12

Cell respiration in producers, consumers an saprotrophs + combustion of fossil fuels

Question 13

Carbon sinks and carbon sources

Answer 13

Carbon sink = more production than respiration (net uptake), carbon source = more respiration than production (net release)