Answer:
Within the bone marrow, all blood cells originate from a single type of unspecialized cell called a stem cell. When a stem cell divides, it first becomes an immature red blood cell, white blood cell, or platelet-producing cell.
Explanation:
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Answer:
A. proteins
Explanation:
Amino acids builds up the proteins.
Answer:
25. red
24. A. Temperature and Luminoscity
Explanation: