In case of taster and non-taster human beings T is for dominance & t is for recessive gene. Which of the following would not be able to taste PTC :-

Options

A. TT
B. Tt
C. tt
D. None

Answer

To determine which individuals would not be able to taste PTC (phenylthiocarbamide), we need to analyze the genetic conditions associated with tasting and non-tasting.

### Step-by-Step Solution:

1. **Understand the Alleles**:
- The dominant allele for tasting PTC is represented as **T**.
- The recessive allele for non-tasting is represented as **t**.

2. **Identify the Genotypes**:
- **Homozygous Dominant (TT)**: Individuals with this genotype have two dominant alleles. They can taste PTC and will find it very bitter.
- **Heterozygous (Tt)**: Individuals with one dominant and one recessive allele can also taste PTC, but it may taste less bitter compared to homozygous dominant individuals.
- **Homozygous Recessive (tt)**: Individuals with this genotype have two recessive alleles. They cannot taste PTC at all.

3. **Determine the Question**:
- The question asks which genotype would **not** be able to taste PTC.

4. **Analyze the Options**:
- **Option 1: TT** - Can taste PTC (homozygous dominant).
- **Option 2: Tt** - Can taste PTC (heterozygous).
- **Option 3: tt** - Cannot taste PTC (homozygous recessive).
- **Option 4: None** - This option implies all can taste PTC, which is incorrect.

5. **Conclusion**:
- The individuals with the genotype **tt** (homozygous recessive) would not be able to taste PTC.

### Final Answer:
- The individuals that would not be able to taste PTC are those with the genotype **tt**.