A cross between two pea plants, tall with axial flowers and dwarf with terminal flowers, produced offspring tall with axial flowers and tall with terminal flowers in the ratio 1:1. What will be genotypes of parents

Options

A. `T TAa xx `ttaa`
B. `TtAa xx ttaa
C. `TtA A xx ttaa
D. `T TA A xx ttaa

Answer

To determine the genotypes of the parent pea plants in the given cross, we can follow these steps:

### Step 1: Identify the traits and their dominance
- The traits involved are:
- Tall (T) vs. Dwarf (t)
- Axial (A) vs. Terminal (a)
- Tallness (T) and axial flowers (A) are dominant traits, while dwarfism (t) and terminal flowers (a) are recessive traits.

### Step 2: Analyze the offspring
- The offspring produced from the cross are:
- Tall with axial flowers
- Tall with terminal flowers
- The ratio of the offspring is 1:1, which indicates that there are two different phenotypes among the offspring.

### Step 3: Determine the genotype of the dwarf parent
- The dwarf parent has terminal flowers, which means it must be homozygous recessive for both traits. Therefore, the genotype of the dwarf parent is:
- Genotype: tt aa (homozygous recessive for both traits)

### Step 4: Determine the genotype of the tall parent
- The tall parent must be heterozygous for the traits to produce both types of tall offspring (with axial and terminal flowers).
- Since the offspring include both tall with axial flowers and tall with terminal flowers, the tall parent must have at least one dominant allele for tallness and one dominant allele for axial flowers. Therefore, the genotype of the tall parent is:
- Genotype: Tt Aa (heterozygous for both traits)

### Conclusion
- The genotypes of the parents are:
- Tall parent: Tt Aa
- Dwarf parent: tt aa