He discovered a new type of medicine that could treat infections.
He discovered the 1st antibiotic (penicillin).
A benign tumour is generally not dangerous as they grow usually within a membrane in one space. They can however grow really big in a short space of time and can cause pressure on neighbouring blood vessels which can be dangerous.
Metastatic or malignant tumours are dangerous and cancerous. After they grow, some cells break off and travel in the bloodstream to a different area of the body (usually the main organs) and forms a secondary tumour there. This keeps happening until the cancer has spread to all of the body.
**_hope this helps**
Correct answer is (D. Once created in bone marrow, they circulate for our lifetime)
Anaerobic respiration<span> is in muscles. Glucose is not completely broken down, so much less energy is released than during </span>aerobic respiration<span>. There is a build-up of lactic acid in the muscles during vigorous exercise. The lactic acid needs to be oxidised to carbon dioxide and water later.</span>
