**Question:** All of the following statements about Lambda phage are true, EXCEPT:

A. Lambda phage is a bacteriophage that infects Escherichia coli bacteria and is used as a biological tool in molecular biology research.
B. Lambda phage has a highly specific host range, infecting only certain strains of E. coli.
C. Lambda phage is involved in the process of genetic recombination in bacteria.
D. Lambda phage is responsible for causing disease in humans.

**Correct Answer:** D. Lambda phage is responsible for causing disease in humans.

**Core Concept:**
Lambda phage is a bacteriophage, a virus that infects bacteria, and is commonly used in molecular biology research for its ability to infect and modify the DNA of Escherichia coli (E. coli) bacteria. It has a highly specific host range, meaning it can only infect particular strains of E. coli. Lambda phage is involved in the process of genetic recombination in bacteria, where it can integrate its DNA into the host's genome and alter its genetic makeup.

**Why the Correct Answer is Right:**
Lambda phage is not responsible for causing disease in humans. It is a non-pathogenic bacteriophage that primarily infects and modifies the DNA of E. coli bacteria in a controlled laboratory setting. It does not have the ability to infect and replicate within human cells or cause disease in humans.

**Why Each Wrong Option is Incorrect:**

A. This option is correct as it highlights the usefulness of Lambda phage in molecular biology research and its specific host range.
B. Although Lambda phage has a specific host range, this statement is incorrect because Lambda phage does not cause disease in humans.
C. This statement is correct as it explains the role of Lambda phage in genetic recombination in bacteria.
D. As mentioned earlier, Lambda phage is not responsible for causing disease in humans. It is used for research purposes on E. coli bacteria, not for causing disease in humans.

**Clinical Pearl:**
Lambda phage is a valuable tool in molecular biology research and genetic engineering due to its specific host range and ability to integrate its DNA into the host's genome. However, it is essential to understand that Lambda phage does not cause disease in humans and should be used appropriately in a controlled laboratory setting.