Which of the following pairs in wrognly matched ?

Options

A. ABO blood grouping : Co-dominance
B. XO type sex-Grassphopper determination
C. Starch synthesis in pea : Multiple alleles
D. T.H. Morgan: Linkage

Answer

To determine which of the following pairs is wrongly matched, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Option A: ABO Blood Grouping and Co-dominance**
- The ABO blood group system consists of three alleles: IA, IB, and i.
- In this system, both IA and IB are co-dominant to each other, meaning that when both alleles are present (as in blood type AB), both A and B antigens are expressed equally.
- Therefore, this pair is correctly matched.

2. **Option B: Grasshopper and XO Sex Determination**
- In grasshoppers, the sex determination system is indeed of the XO type.
- Males have one X chromosome (XO), while females have two X chromosomes (XX).
- This pair is also correctly matched.

3. **Option C: Thomas Hunt Morgan and Linkage**
- Thomas Hunt Morgan is known for his work on genetic linkage, which refers to the tendency of genes located close to each other on a chromosome to be inherited together.
- His experiments with fruit flies (Drosophila) provided evidence for this concept.
- Therefore, this pair is correctly matched.

4. **Option D: Pea Plant Starch Synthesis and Multiple Alleles**
- In pea plants, starch synthesis is controlled by two alleles: B (dominant) and b (recessive).
- This means that there are not multiple alleles involved in this trait; rather, it follows a simple dominant-recessive relationship.
- Therefore, this pair is incorrectly matched since starch synthesis in pea plants does not involve multiple alleles but rather two alleles.

### Conclusion:
The wrongly matched pair is **Option D: Pea Plant Starch Synthesis and Multiple Alleles**.

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