Review Sheet - Energetics in Marine Ecosystems

Review Sheet - Energetics in Marine Ecosystems

1. Explain the meaning of the following terms:

a. Photosynthesis. [3]

i. Process of converting light energy from the sun into glucose from carbohydrates and organic substances

ii. CO2+H2O+sunlight → O2+C6H12O6 (glucose)

iii. This process allows energy to become available to higher tropic levels

iv. Factors that affect photosynthesis

1. Transparency/clarity of water

2. Depth

3. Nutrients in water

b. Chemosynthesis. [3]

i. Process of capturing chemical energy of dissolved minerals in the deep sea such as hydrogen sulfide to produce organic compounds such as carbohydrates

ii. Occurs because there is no light in the deep sea for photosynthesis to occur

c. Predator [2]

i. An animal that eats another animals

ii. Usually secondary consumers in food chains and include carnivores

d. Tropic level [2]

i. "Feeding levels" in a food chain or a food wed

ii. Producer → primary consumer → secondary consumer

e. Producer [1]

i. Synthesizes organic substances form simple organic compounds using light energy from the sun--photosynthesis

ii. Producers provide food for almost all other organisms in food chains/webs

f. Primary consumer [1]

i. An organism that obtains its energy requirements by feeding on other organisms

1. Primary consumers (herbivores) feed on plants materials

2. Secondary consumers (carnivores) feed on herbivore

g. Primary productivity [1]

i. Rate of production of biomass per unit area per year (or per unit volume in aquatic ecosystems)

2. What is primary source of energy? [1]

a. Sun light

3. Explain why not all the energy from the sun becomes available as net production in phytoplankton [3].

a. Only 1% of the total energy from the sun is captured by Earth and used for the synthesis of organic substances by phytoplankton. Light energy is reflected by surfaces or may pass through a producer without being absorbed