Genotype of male plant is TT and genotype of female plant is tt. What would be the genotype of endosperm?

Options

A. TTt
B. Ttt
C. Tt
D. tt

Answer

To determine the genotype of the endosperm resulting from the cross between a male plant with the genotype TT and a female plant with the genotype tt, we can follow these steps:

### Step 1: Understand the Genotypes
- The male plant has the genotype TT (homozygous dominant).
- The female plant has the genotype tt (homozygous recessive).

### Step 2: Identify Gametes
- The male plant can produce gametes that carry the T allele (since it is TT).
- The female plant can produce gametes that carry the t allele (since it is tt).

### Step 3: Fertilization Process
- During fertilization, one male gamete (T) will fertilize the female gamete (t) to form the zygote.
- In addition to this, the male plant contributes another male gamete to the female gametophyte, which is a binucleated central cell that contains two t alleles (tt).

### Step 4: Formation of Endosperm
- The endosperm is formed by the fusion of one male gamete (T) with the binucleated central cell (tt).
- Therefore, the genotype of the endosperm will be the combination of these alleles.

### Step 5: Determine the Genotype of Endosperm
- The endosperm will have the genotype T (from the male gamete) combined with the two t alleles from the female gametophyte.
- Thus, the genotype of the endosperm will be Tt (triploid: Ttt).

### Conclusion
The genotype of the endosperm will be **Tt**.

### Answer:
The correct answer is **Option B: Tt (capital T small t small t)**.

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