Genotype of hybrid is known by crossing

Options

A. `F_(2)` progeny with female parent
B. `F_(1) xxF_(1)`
C. Crossing `F_(1)` with recessive parent
D. `F_(2)` with recessive parent.

Answer

To determine the genotype of a hybrid, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Genotype and Hybrid**:
- A hybrid organism is typically the offspring of two different varieties or species. The genotype refers to the genetic makeup of an organism.

**Hint**: Remember that the genotype can be homozygous (two identical alleles) or heterozygous (two different alleles).

2. **Identify the Purpose of the Test Cross**:
- A test cross is a method used to determine the genotype of an individual with a dominant phenotype. It involves crossing the individual with a homozygous recessive individual.

**Hint**: The test cross helps reveal whether the dominant phenotype is due to a homozygous or heterozygous genotype.

3. **Perform the Test Cross**:
- Cross the F1 hybrid (whose genotype we want to determine) with a homozygous recessive parent. This means the recessive parent has two recessive alleles (e.g., aa).

**Hint**: The recessive parent must always be homozygous to ensure that any recessive phenotype in the offspring can be attributed to the hybrid's genotype.

4. **Analyze the Offspring (Progeny)**:
- If all offspring display the dominant phenotype, the hybrid is likely homozygous dominant (AA). If the offspring show a 1:1 ratio of dominant to recessive phenotypes, the hybrid is heterozygous (Aa).

**Hint**: The phenotypic ratio in the offspring will give you clues about the genotype of the hybrid.

5. **Conclude the Genotype of the Hybrid**:
- Based on the analysis of the offspring, you can conclude the genotype of the hybrid.

**Hint**: Remember that a 100% dominant phenotype indicates a homozygous dominant genotype, while a 50% dominant and 50% recessive phenotype indicates a heterozygous genotype.

### Final Answer:
The genotype of a hybrid is known by the crossing called a **test cross**, which involves crossing the F1 hybrid with a homozygous recessive parent.