Final answer:
Human blood does contain red blood cells, white blood cells, and platelets. However, mature human red blood cells do not have a nucleus, and the ABO blood typing system is specific to humans and not shared by all animals. Platelets play a vital role in blood clotting.
Step-by-step explanation:
To answer the question about animal versus human blood, let's review the true statements:
- Human blood contains red blood cells, white blood cells, and platelets - this is true.
- Human red blood cells contain a very large & defined nucleus - this is false. Mature human red blood cells lack nuclei at maturity, allowing more space for hemoglobin.
- All animals (including humans) belong to the ABO blood typing system - this is false. The ABO blood typing system is specific to humans, and not all animals share this system.
- A positive precipitin test indicates that the sample is that of a human - while this statement can be true, it requires more context. The precipitin test detects the presence of human proteins, but additional tests may be needed for conclusive results.
Reviewing blood cells, red blood cells are the most numerous and consist mostly of hemoglobin, which carries oxygen. White blood cells protect the body from harmful substances and are key to the immune system. They have nuclei and vary in immune functions. Platelets are crucial for blood clotting or coagulation.