Lecture Focus Questions; Cycles of Matter & Energy

Question 1

What are Autotrophs?

Answer 1

• They are capable of extracting their carbon from CO2

- They are also subdivided into Photoautotrophs & Chemolithoautotrophs

Question 2

What are Heterotrophs?

Answer 2

• They get their carbon from organic compounds/ foods in their environment
• They are also subdivided into Photoheterotrophs & Chemoheterotrophs

Question 3

What are Photoautotrophs?

Answer 3

-They extract energy from sunlight= photosynthesis

Question 4

What are Chemolithoautotrophs

Answer 4

-They extract energy from the oxidation of organic compounds

Question 5

What are Photoheterotrophs?

Answer 5

-They also get their energy from the sun

Question 6

What are Chemoheterotrophs?

Answer 6

-They get their energy from consuming energy-rich reduced organic molecules

Question 7

What is the energy flow in the biosphere?

Answer 7

-It is a one-way flow of energy= originates in the sun & ending up as energy loss to “waste heat”

Question 8

What are Trophic Levels?

Answer 8

• They are the manifestation of different kinds of producers & consumers
• The energy levels are also inefficient= 10% of energy available passes through these levels while the 90% is used to keep the organisms at each level alive

Question 9

What are Reservoirs?

Answer 9

-They are Abiotic sites that contain materials that are needed by biological systems

Question 10

How does the movement from abiotic reservoirs to biotic compartments of the ecosystem occur?

Answer 10

-It occurs by incorporation into biological systems & is then returned abiotic when organisms die & are broken down into organic compounds by decomposers

Question 11

What are the 3 types of Reservoirs?

Answer 11

• Water
• Air
• Sediment

Question 12

What reservoir does H come from?

Answer 12

-It comes from H20= water reservoir

Question 13

What reservoir does C come from?

Answer 13

• It comes from CO2= air reservoir

Question 14

What reservoir does O come from?

Answer 14

-It can come from H2O or CO2= water or air reservoir

Question 15

What reservoir does S and P come from?

Answer 15

-Sediment reservoir

Question 16

What is the Carbon Cycle?

Answer 16

• It involves carbon atoms in the form of CO2 leaving the atmospheric reservoir & being incorporated into producers which passes it on to consumers
• Carbon is then returned to the atmosphere as CO2 by the producers & consumers

Question 17

Why has allowed the Carbon cycle to stay in balance?

Answer 17

-It stayed in balance bc of the opposing processes of photosynthesis & respiration

Question 18

What is a Greenhouse Gas?

Answer 18

-It is a gas that traps radiant energy from the sun as heat

Question 19

What are the 2 most powerful greenhouse gasses?

Answer 19

• Carbon dioxide

- Methane

Question 20

What are Fossil Fuels?

Answer 20

-They are fuels like coal, oil. and gas that have been derived originally from biological processes

Question 21

What is the evidence for increased concentration of CO2 in the atmosphere?

Answer 21

• The keeling curve= measured at a remote location in Hawaii for the last 60 years
• The curve shows a smooth increase in CO2 from 315ppm in 1960 to over 415ppm now

Question 22

What is the evidence that increased CO2 is due to burning Fossil Fuels?

Answer 22

• The evidence is via isotope analysis
• The ratio of C12 & C13 has been increasing BUT the decrease of C14 says that the source fo the increase of CO2 is due to fossil fuels

Question 23

What 3 processes might have led to natural cooling of the Earth’s climate during earlier times?

Answer 23

• The oxidation of methane to CO2
• Volcanic activity that ejected ash & sulfur oxides into the atmosphere (reflects sunlight)
• The incorporation of more atmospheric CO2 into the biomass of newly evolved organisms during the time of plant growth=jurassic

Question 24

What process might have led to the natural warming of the Earth’s climate during earlier times?

Answer 24

-The increased volcanic activity that ejected CO2 into the atmosphere

Question 25

What is the relationship between C,H & O in terms of the cycling matter in the biosphere?

Answer 25

• Photosynthesis & respiration control the carbon cycle & brings H & O in & out biological systems
• SO photosynthesis uses water as the source of electrons & H atoms to make reduced C compounds & releases O2
• While O2 is used for respiration by both consumers & producers