Refer to the given dichotomous key and identify P,Q R,S ,T and U
I. (a) It is a communicable disease. - Go to II
(b) It is a non-communicable disease - Go to V
II. (a) Direct transmission - Go to III
(b) Indirect transmission - Go to IV
III. (a) Spreads through sexual contact - P
(b) Spreads through physical contact and use of infected articles - Q
IV . (a) Transmitted through vectors - R
(b) Spreads through contaminated food and water -S
V. (a) Uncontrolled proliferation of cells -T
(b) Hypersensitivity to certain antigens such as dust, pollen , etc. - U

Options

A. P-Gonorrhoea, Q - Measles, R - Malaria, S- Cholera, T - Cancer, U-Hay fever
B. P-Syphilis, Q-Small pox, R- Elephantiasis, S-Tetanus, T - Cancer, U-AIDS
C. P- Hepatitis B, Q-Syphilis, R - Tuberculosis, S-Kala azar, T - Plague, U-Cretinism
D. P-AIDS, Q-Rabies, R-Sleeping sickness, S-Dengue, T-Yellow fever, U-Conjunctivitis

Answer

To identify the diseases represented by P, Q, R, S, T, and U based on the given dichotomous key, we will follow the steps outlined in the key.

### Step-by-Step Solution:

1. **Identify Communicable vs Non-Communicable Diseases:**
- The first question in the key asks if the disease is communicable or non-communicable.
- If it is a communicable disease, we go to step II. If it is non-communicable, we go to step V.

2. **Communicable Diseases:**
- In step II, we determine if the communicable disease is transmitted directly or indirectly.
- If it is through direct transmission, we go to step III. If it is through indirect transmission, we go to step IV.

3. **Direct Transmission (Step III):**
- In step III, we have two options:
- (a) If it spreads through sexual contact, it is identified as **P**. This could be diseases like gonorrhea or syphilis.
- (b) If it spreads through physical contact and the use of infected articles, it is identified as **Q**. This could be diseases like measles or mumps.

4. **Indirect Transmission (Step IV):**
- In step IV, we again have two options:
- (a) If it is transmitted through vectors, it is identified as **R**. This could be diseases like malaria or dengue.
- (b) If it spreads through contaminated food and water, it is identified as **S**. This could be diseases like cholera.

5. **Non-Communicable Diseases:**
- In step V, we have:
- (a) If it is due to uncontrolled proliferation of cells, it is identified as **T**. This is typically cancer.
- (b) If it is due to hypersensitivity to certain antigens (like dust or pollen), it is identified as **U**. This could be an allergic reaction or condition like hay fever.

### Final Identification:
- **P**: Gonorrhea or Syphilis (spreads through sexual contact)
- **Q**: Measles (spreads through physical contact and use of infected articles)
- **R**: Malaria (transmitted through vectors)
- **S**: Cholera (spreads through contaminated food and water)
- **T**: Cancer (uncontrolled proliferation of cells)
- **U**: Allergic reactions (hypersensitivity to certain antigens)

### Summary of Identifications:
- **P**: Gonorrhea/Syphilis
- **Q**: Measles
- **R**: Malaria
- **S**: Cholera
- **T**: Cancer
- **U**: Allergic reactions