Assertion (A) : Homo sapiens have evolved from chimpanzee-like ancestors. Reason (R) : There is no difference between the two in the amino acid sequence of the protein Cytochrome-C.

The correct answer is: Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).

Step-by-step Explanation:

1. Understanding the Assertion (A):
Assertion (A) states: "Homo sapiens have evolved from chimpanzee-like ancestors."
From an evolutionary biology standpoint, humans (Homo sapiens) and chimpanzees (Pan troglodytes) share a common hominid ancestor that lived approximately 6 to 8 million years ago. Over time, evolutionary pressures led to divergence from this chimpanzee-like ancestor into modern chimpanzees and modern humans. Therefore, Assertion (A) is scientifically true.

2. Understanding the Reason (R):
Reason (R) states: "There is no difference between the two in the amino acid sequence of the protein Cytochrome-C."
Cytochrome-c is a highly conserved mitochondrial protein consisting of 104 amino acids, playing a key role in the electron transport chain. When scientists compare the sequence of these 104 amino acids between humans and chimpanzees, they find that the sequence is 100% identical (0 differences). Hence, Reason (R) is also scientifically true.

3. Checking the Connection (Explanation):
Molecular biology and biochemical comparisons of proteins (like Cytochrome-c) are used as strong evidence to establish evolutionary relationships. A higher similarity in the amino acid sequences of shared proteins indicates a closer evolutionary relationship and a more recent common ancestor. Since the amino acid sequence of Cytochrome-c in humans and chimpanzees is identical, it provides biochemical proof that they are extremely closely related and have evolved from a common chimpanzee-like ancestor. Thus, Reason (R) is the correct explanation of Assertion (A).