In an organism, tall phenotype is dominant over recessive dward phenotype, and the alleles are designated as T and t, respectively. Upon crossing two different individuals, total 250 offsprings were obtained, out of which 124 displayed tall phenotype and rest were dwarf. Thus, the genotype of the parents were
(a) TT × TT
(b) TT × tt
(c) Tt × Tt
(d) Tt × tt

Options

A. TT `xx` TT
B. TT `xx` tt
C. Tt `xx` Tt
D. Tt `xx` tt

Answer

To determine the genotypes of the parents based on the given offspring phenotypes, we can analyze the information provided step by step.

### Step 1: Understand the Phenotypes and Genotypes
- Tall phenotype (dominant) = T
- Dwarf phenotype (recessive) = t
- The offspring count is 250, with 124 tall and the rest dwarf.

### Step 2: Calculate the Number of Dwarf Offspring
- Total offspring = 250
- Tall offspring = 124
- Dwarf offspring = Total offspring - Tall offspring = 250 - 124 = 126

### Step 3: Determine the Phenotypic Ratio
- The ratio of tall to dwarf offspring is 124:126, which simplifies to approximately 1:1.
- This indicates that for every tall offspring, there is roughly one dwarf offspring.

### Step 4: Analyze the Options
1. **TT × TT**: All offspring would be tall (TT), so this cannot be correct.
2. **TT × tt**: All offspring would be heterozygous tall (Tt), so this cannot be correct.
3. **Tt × Tt**: This would produce a 3:1 ratio (1 TT : 2 Tt : 1 tt), which does not match our observed ratio of 1:1.
4. **Tt × tt**: This would produce a 1:1 ratio (1 Tt : 1 tt), which matches our observed ratio of tall to dwarf offspring.

### Conclusion
Based on the analysis, the correct genotypes of the parents are:
**(d) Tt × tt**