In higher vertebrates, the immune system can distinguish self cels and non self. If this property is lost due to genetic abnormality and it attacks selfcells, then it it leads to

Options

A. Allergic response
B. Graft rejection
C. Auto immune disease
D. Active immunity

Answer

### Step-by-Step Solution:

1. **Understanding the Immune System**: The immune system in higher vertebrates is designed to differentiate between self-cells (the body’s own cells) and non-self cells (foreign invaders like pathogens).

**Hint**: Remember that the immune system's ability to distinguish between self and non-self is crucial for maintaining health.

2. **Loss of Distinction**: If there is a genetic abnormality that causes the immune system to lose this ability, it can mistakenly identify self-cells as foreign.

**Hint**: Consider what happens when the immune system misidentifies cells; it can lead to harmful consequences.

3. **Consequences of Misidentification**: When the immune system attacks self-cells, it leads to damage and dysfunction in the body’s own tissues.

**Hint**: Think about the implications of the immune system attacking its own cells—what kind of diseases might arise from this?

4. **Autoimmune Disorders**: This condition where the immune system attacks self-cells is known as an autoimmune disorder.

**Hint**: Recall that autoimmune disorders can manifest in various forms and affect different parts of the body.

5. **Examples of Autoimmune Disorders**: One specific example of an autoimmune disorder is rheumatoid arthritis, where the immune system attacks the joints.

**Hint**: Consider other examples of autoimmune disorders that might affect different organs or systems in the body.

### Summary:
The loss of the immune system's ability to distinguish between self and non-self due to genetic abnormalities leads to autoimmune disorders, such as rheumatoid arthritis, where the body attacks its own cells.