Biogeochemical Cycles
Chapter Name : Natural Resources |
Sub Topic Code : 103_09_14_05_05 |
Topic Name : Biogeochemical Cycles |
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Sub Topic Name : The Oxygen Cycle |
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Introduction
Oxygen is an abundant element in the atmosphere and is found in the earth’s crust and in the form of carbon dioxide.
Pre-Requisites:
Information on processes of combustion, respiration and photosynthesis
Real Life Question:
Oxygen is used by most of the life forms for survival. So how does oxygen content does not get depleted on the earth?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Presence of oxygen | In the earth’s crust, it is found as the oxides of most metals and silicon and also as carbonate, sulphate, nitrate and other minerals. |
| Biological molecules | Essential component of most biological molecules like carbohydrates, proteins, nucleic acids and fats. |
| Oxygen cycle | Oxygen is used up in 3 processes namely combustion, respiration and in the formation of oxides of nitrogen and oxygen is returned back only by photosynthesis. |
| Organisms not requiring oxygen | Oxygen is poisonous to many bacteria. Nitrogen fixing bacteria do not require oxygen. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Encyclopedia and internet | Find the list of organisms that are harmed by the presence of oxygen. |
Real life uses :
Excessive deforestation has led to imbalance in the oxygen cycle.
Practical examples around us
| Examples | Explainations |
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What you learn in Theory:
Use of oxygen during respiration, combustion, etc and oxygen is returned back through photosynthesis.
What you learn in Practice:
How level of oxygen is maintained in the atmosphere.