Single domain antibodies are

Options

A. Effective against only one type of antigen
B. Effective against whole range of bacteria
C. Effective against both bacteria and viruses
D. Small part of antibody which can combine with variety of materials

Answer

To answer the question about single domain antibodies, we can break down the solution into the following steps:

### Step 1: Understand the Concept of Antibodies
Antibodies are protein molecules produced by the immune system in response to antigens. They play a crucial role in identifying and neutralizing pathogens like bacteria and viruses.

**Hint:** Remember that antibodies are specific to antigens, and they come in different classes (IgG, IgA, IgM, IgE, IgD).

### Step 2: Define Single Domain Antibodies
Single domain antibodies (sdAbs) are a type of antibody that consists of a single monomeric unit. They are derived from the variable regions of heavy chain antibodies and are much smaller than conventional antibodies.

**Hint:** Focus on the term "single domain," which indicates that these antibodies are smaller and simpler than traditional antibodies.

### Step 3: Analyze the Options Given
The question provides several options regarding the effectiveness of single domain antibodies:
1. Effective only against one type of antigen
2. Effective against a whole range of bacteria
3. Effective against bacteria and viruses
4. Small part of the antibody which can combine with a variety of materials

**Hint:** Consider the versatility of single domain antibodies in their ability to bind to various targets.

### Step 4: Identify the Correct Option
Among the options, the most accurate description of single domain antibodies is that they are a small part of the antibody which can combine with a variety of materials. This indicates their ability to bind to different antigens, not just one specific type.

**Hint:** Look for the option that highlights the adaptability and binding capability of single domain antibodies.

### Conclusion
Based on the analysis, the correct answer to the question is:
**Single domain antibodies are a small part of the antibody which can combine with a variety of materials.**

**Final Answer:** Option 4 is the correct choice.

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