Which statement is not correct :-

Options

A. ABO blood group is an example of multiple allelism
B. Law of independent assortment is based on monohybrid cross
C. A set of haploid chromosome known as genome
D. X-body name given by Henking

Answer

To determine which statement is not correct, let's analyze each option one by one:

1. **ABO blood group is an example of multiple allelism.**
- This statement is **correct**. The ABO blood group system is indeed an example of multiple allelism because it is controlled by three alleles: I^A, I^B, and i.

2. **Law of independent assortment is based on the monohybrid cross.**
- This statement is **not correct**. The law of independent assortment is actually based on the dihybrid cross, which involves two traits being studied simultaneously. A monohybrid cross only considers one trait.

3. **A set of haploid chromosomes is known as a genome.**
- This statement is **correct**. A genome refers to the complete set of genes or genetic material present in a cell or organism, and in haploid organisms, this set consists of a single set of chromosomes.

4. **X body was named by Henking.**
- This statement is **correct**. The term "X body" refers to the sex chromosome identified by Hermann Henking in the late 19th century.

Based on the analysis, the statement that is not correct is the second one: "Law of independent assortment is based on the monohybrid cross."

### Step-by-Step Solution:

1. **Identify the statements provided in the question.**
- List down the statements for analysis.

2. **Evaluate each statement for correctness.**
- Check the first statement about ABO blood groups and confirm it is correct.
- Check the second statement regarding the law of independent assortment and identify it as incorrect.
- Check the third statement about haploid chromosomes being a genome and confirm it is correct.
- Check the fourth statement about the X body and confirm it is correct.

3. **Determine which statement is incorrect.**
- Conclude that the second statement is the one that is not correct.