On the basis of serological tests, which one is closest to man?

Options

A. Baboon
B. Chimpanzee
C. Gorilla
D. Monkey

Answer

**Step-by-Step Text Solution:**

1. **Understanding Serological Tests**:
- Serological tests involve analyzing blood serum, which is the liquid part of blood that remains after clotting. It contains antibodies and proteins but lacks cells and clotting factors like fibrinogen.

2. **Identifying the Purpose of Serological Tests**:
- The main purpose of serological tests in this context is to compare the protein structures (specifically antibodies) of different organisms with those of humans to determine evolutionary relationships.

3. **Examining Evolutionary Relationships**:
- To determine which organism is closest to humans based on serological tests, we can look at the evolutionary tree of primates. This tree shows the divergence of various species from common ancestors.

4. **Analyzing the Evolutionary Tree**:
- In the evolutionary tree:
- Monkeys are the first to diverge from the common ancestor.
- Next, orangutans diverge from the lineage.
- Following this, gorillas split off.
- Finally, chimpanzees and humans share a more recent common ancestor.

5. **Conclusion**:
- Based on the evolutionary tree and serological tests, chimpanzees are the closest relatives to humans. This is supported by both genetic similarities and the structure of proteins found in their serum.

**Final Answer**: The organism that is closest to man based on serological tests is the chimpanzee.

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