Environment G (Qs) Unit 3

Question 1

Explain how it is possible that biogeochemical cycles connect living organisms from the past to living organisms of the present

Answer 1

Biogeochemical moves the matter between the abiotic and biotic parts of the ecosystem

(atom from past organism left that organism to the abiotic (ground party through decomposition-picked up by producers, atom flow through food chain- process repeats)

Matter is never destroyed, only transferred or transformed

Question 2

Using the equation for cellular respiration, explain how organisms return carbon dioxide (CO2) to the atmosphere

Answer 2

First, the equation for cellular respiration is glucose and oxygen yields carbon and water

Cellular respiration happens in the mitochondria which are a part of the cells in the organism and releases carbon dioxide as a product into the atmosphere

Question 3

Explain why phosphorus is often a limiting factor for producers’ ecosystems and for producers in freshwater ecosystems

Answer 3

Soil contains little phosphorus and it’s not very soluble in water

o Why is there so little? Generally has a one way flow (from land to the ocean) and does not have a gases phase. Phosphorus slowly erodes from rock, the run off from the land carries it to the river then the ocean, then it sinks and becomes ocean sediments, then the geological uplifting over a long period of time brings the sediments to be exposed, forming rocks, and other things

Most is in rock and sediments, so plants can’t get to it

Question 4

Explain how oxygen cycle is related to other cycles

Answer 4

Oxygen typically combines with other atoms as they travel in their cycle, Water cycle (H2O), Carbon Cycle (Carbon dioxide and glucose), Nitrogen Cycle (Nitrite and Nitrate), Phosphorus Cycle (Phosphate)

Question 5

Relate the second law of thermodynamics to the following statement: You reuse or high-quality energy to do useful work

Answer 5

The 2nd law of thermodynamics states that as energy changes form it becomes more dispersed and the dispersed energy is not as useful. The 1st law of thermodynamics states that Energy can’t be created or destroyed but it can change form

Therefore you cannot recycle or reuse high-quality energy to do useful work

Question 6

Relate the available net primary productivity of the earth to the degradation of these ecosystems and explain the significance in terms of energy flow for there ecosystems

Answer 6

Primary productivity is how much food producers make food for the food chain. These areas have high productivity, thus they put a lot more energy into the food chain which allows more energy throughout the trophic levels

Eliminating these areas will reduce amount of energy going into the chain, which will disrupt the stability of the food webs and a loss of biodiversity.

The food production at a lower rate will impact the entire productivity of the earth