Which one of the following conditions correctly describes the manner of determining the sex in the given example

Options

A. (a) Homozygous sex chromosomes (ZZ) determine female sex in birds
B. (b) XO type of sex chromosomes determine male sex in grasshopper
C. (c) XO condition in humans as found in turner syndrome, determines female sex
D. (d) Homozygous sex chromosomes (XX) produce male in Drosophila

Answer

To determine the correct condition describing the manner of sex determination in the given examples, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement A: Homozygous sex chromosome ZZ determines female sex in birds.**
- In birds, the sex determination system is ZW. The homozygous condition ZZ actually denotes male birds, while the heterozygous condition ZW denotes female birds. Therefore, this statement is **false**.

2. **Statement B: XO type of sex chromosome determines male sex in grasshopper.**
- In grasshoppers, the sex determination system is XX-XY. The XO condition (where there is one X and no second sex chromosome) denotes male grasshoppers, while the XX condition denotes females. This statement is **true**.

3. **Statement C: XO condition in humans found in Turner syndrome determines male sex.**
- Turner syndrome is a genetic disorder characterized by the presence of a single X chromosome (XO). However, this condition does not determine male sex in humans; rather, it is a condition that occurs in females. In humans, the sex is determined by the XX (female) and XY (male) system. Therefore, this statement is **false**.

4. **Statement D: Homozygous sex chromosomes XX produce male in Drosophila.**
- In Drosophila (fruit flies), the sex determination is based on the ratio of X chromosomes to autosomes (A). The XX condition actually denotes females, while the XY condition denotes males. Hence, this statement is **false**.

5. **Conclusion:**
- The only correct statement among the options provided is **Statement B**, which states that the XO type of sex chromosome determines male sex in grasshoppers.

### Final Answer:
The correct condition that describes the manner of determining sex in the given example is **Statement B**.

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