4 billion years ago the temperature was much higher due to repeated volcanoes and hot gases present in the atmosphere. There weren't any live forms on earth. ... The atmosphere had a different concentration of gases on the earth. There were no life sustaining gases.
The categories of energy expenditure include the following:
- Resting metabolic rate - This is the total number of calories burned when your body is completely at rest and accounts for 60-75 percent
- Thermic effect of feeding - This happens during feeding in which the metabolic rate increases and heat is produced and accounts for 5-15 percent
- The thermic effect of activity - the amount of energy burned during all physical activity and accounts for 15-30 percent.
<h3>What is Energy expenditure?</h3>
These are the processes which involves how energy is used or spent. The categories are mentioned above with their appropriate explanations.
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