Answered

Based on the monohybrid cross, which of the following are the parents?

\begin{tabular}{|c|c|}
\hline
A. Dd & dd \\
\hline
B. DD & Dd \\
\hline
C. Dd & DD \\
\hline
D. dd & Dd \\
\hline
\end{tabular}



Answer :

Let's analyze the problem of identifying the parents based on a monohybrid cross using classical Mendelian genetics.

### Understanding Monohybrid Cross
In a monohybrid cross, we examine the inheritance of a single pair of contrasting traits. Typically, we use the notation:
- "D" for the dominant allele
- "d" for the recessive allele

### Given Tabular Phenotypes
```
| Dd | dd |
|----|----|
| DD | Dd |
```
This table presents the offspring phenotypes, which arise from crossing certain parent genotypes. We need to determine which parent genotypes most likely produce these offspring phenotypes.

### Possible Parent Pairs:
1. Dd and DD: A parent with genotype "Dd" crossed with a parent with genotype “DD”.
2. Dd and Dd: Both parents have the genotype "Dd".
3. DD and dd: One parent has genotype "DD", and the other "dd".
4. dd and Dd: One parent has genotype "dd", and the other "Dd".

### Analysis of Possible Parent Pairs

#### 1. Dd and DD:
- Possible offspring genotypes: DD, Dd
- This does not fit completely with the given table that also includes "dd".

#### 2. Dd and Dd:
- Possible offspring genotypes: DD, Dd, dd
- The genotype combinations are:
- D from first parent + D from second parent = DD
- D from first parent + d from second parent = Dd
- d from first parent + D from second parent = Dd
- d from first parent + d from second parent = dd
- Fits perfectly with given outcomes.

#### 3. DD and dd:
- Possible offspring genotypes: Dd (only)
- This does not fit with the given table that requires offspring of types DD, Dd, and dd.

#### 4. dd and Dd:
- Possible offspring genotypes: Dd, dd
- This does not fit completely with the given table as it lacks "DD".

### Conclusion
Considering the possible genotypes and the given table, the most probable and fitting parent pair is:

Dd and Dd

This pair explains all the offspring phenotypes (DD, Dd, dd) as per the classical Mendelian genetics rules.

Therefore, the parents are Dd and Dd.