<span>The supply of energy-rich molecules in muscles are used up, then the muscles become tired, and they need to rest.
Lactic acid is being produced from anaerobic respiration. If compared to cellular respiration, fermentation does not produce much energy.</span>
Question 4. Populations, communities. Question 5: Biotic factos
Explanation:
The early atmosphere was mainly carbon dioxide and water vapour. Water vapour condensed to form the oceans. Photosynthesis caused the amount of carbon dioxide to decrease and oxygen to increase.
Answer:
A community is an interacting group of various species in a common location.