Answer:
Explanation:
The weakened virus's structure would be less complex to the normal virus, thus the normal virus would be able to adapt if there are dangerous changes to them.
Answer:
Pulmonary circulation refers to the circulation of blood in which deoxygenated blood is pumped from the heart to the lungs and oxygenated blood is returned to back to the heart. Pulmonary circulation only occurs between the heart and the lungs.
Systemic circulation refers to the circulation of blood in which oxygenated blood is pumped from the heart to the body and deoxygenated blood is returned back to the heart. Systemic circulation occurs between the heart and the entire body
Explanation:
Y.w
Because atmospheric nitrogen can't be used by plants and animals. Only by soil. nitrification it is the conversion of ammonia first into nitrites then into nitrates by nitrifying bacteria and denitrification is the conversion of nitrites and nitrates into free nitrogen. Why are bacteria important to the nitrogen cycle?
During the process of ossification, an existing tissue is replaced by bone.