Question

1. describe the biological origin of the following geological deposits: (a) coal: (b) oil: (c) limestone: (d) peat: 7. using examples, compare and contrast the amount of time carbon spends in its various reservoirs: 8. explain the role of living organisms in the carbon - cycle: 9. accumulated reserves of carbon such as peat, coal, and oil represent a sink or natural diversion from the cycle. in natural circumstances, the carbon in these sinks eventually returns to the cycle through geological processes which return deposits to the surface for oxidation. explain the effect of human activity on the amount of carbon stored in sinks.

Explanation:

(a) Coal is formed from the remains of plant material buried in shallow swamps, which is then compacted under sediment to form a hard - black material.
(b) Oil formed when dead algae and zooplankton settled to the bottom of shallow seas and lakes, and their remains were buried and compressed.
(c) Limestone forms from the fossilization of the shells of mollusks and other marine organisms with calcium carbonate skeletons.
(d) Peat forms when plant material is not fully decomposed due to acidic or anaerobic conditions in wetlands.

For question 7, carbon in the atmosphere has a relatively short residence time (years - decades), for example, through photosynthesis and respiration processes. In the ocean, carbon can be stored for centuries to millennia as dissolved inorganic carbon. In fossil fuels like coal and oil, carbon has been stored for millions of years.

For question 8, plants take in carbon dioxide during photosynthesis and store carbon in their biomass. Animals consume plants and release carbon dioxide during respiration. Decomposers break down dead organic matter and release carbon back into the environment.

For question 9, human activities such as mining and burning of fossil fuels (coal, oil, peat) release large amounts of carbon that has been stored in sinks for long periods back into the atmosphere. This increases the amount of atmospheric carbon and disrupts the natural balance of the carbon cycle, contributing to climate change.

Answer:

(a) Formed from remains of plant material buried in swamps and compacted.
(b) Formed from remains of dead algae and zooplankton buried and compressed in shallow seas and lakes.
(c) Formed from fossilization of shells of marine organisms with calcium - carbonate skeletons.
(d) Formed from partially decomposed plant material in acidic or anaerobic wetland conditions.

1. Carbon in atmosphere has short residence time (years - decades), in ocean for centuries - millennia, in fossil fuels for millions of years.
2. Plants take in CO2 during photosynthesis, animals release CO2 during respiration, decomposers release carbon from dead matter.
3. Human activities like mining and burning fossil fuels release stored carbon, increasing atmospheric carbon and disrupting the carbon - cycle balance.