Which statement is incorrect :-

Options

A. Pleotropic gene has multiple phenotype
B. 9:7 ratio is produced due to lethal gene
C. Two identical alleles known as homozygous
D. Incomplete dominance present in antirrhinum majus

Answer

To determine which statement is incorrect, we will analyze each statement one by one.

### Step 1: Analyze the first statement
**Statement:** Pleiotropic gene has multiple phenotypes.
**Analysis:** Pleiotropic genes are known to affect multiple traits or characteristics. Therefore, if a gene is pleiotropic, it can indeed lead to multiple phenotypes.
**Conclusion:** This statement is **true**.

### Step 2: Analyze the second statement
**Statement:** 9 is to 7 ratio is produced due to lethal gene.
**Analysis:** Lethal genes typically produce a phenotypic ratio of 2:1 due to the death of homozygous individuals. The 9:7 ratio is actually associated with complementary gene action, not lethal genes.
**Conclusion:** This statement is **false**.

### Step 3: Analyze the third statement
**Statement:** Two identical alleles are known as homozygous.
**Analysis:** The term "homozygous" refers to having two identical alleles for a particular gene, such as TT or tt. This is indeed the correct definition.
**Conclusion:** This statement is **true**.

### Step 4: Analyze the fourth statement
**Statement:** Incomplete dominance is present in Antirrhinum majus.
**Analysis:** Antirrhinum majus (snapdragon) is a classic example of incomplete dominance, where crossing a red flower (RR) with a white flower (rr) results in pink flowers (Rr). This demonstrates that the F1 progeny expresses a blend of the two parental traits.
**Conclusion:** This statement is **true**.

### Final Conclusion
After analyzing all statements, the only incorrect statement is the second one: "9 is to 7 ratio is produced due to lethal gene." Therefore, the answer is the second statement.