Sex determination in grasshoppers,humans,and Drosophila is similar because:

Options

A. Femals are hemizygous
B. males have oneX-chrosome and femals have two X-chrosomes
C. all males always have one Y-chromosome in all three species
D. The ratio of autosomes to sex chrosomes is the same in all three organism

Answer

To solve the question about the similarity in sex determination among grasshoppers, humans, and Drosophila, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Sex Chromosomes**:
- In humans, grasshoppers, and Drosophila, sex is determined by the presence of specific sex chromosomes.
- Males typically have one X chromosome and one Y chromosome (XY), while females have two X chromosomes (XX).

2. **Analyzing the Options**:
- **Option A**: "Females are hemizygous" - This is incorrect because females have two X chromosomes, making them homozygous for the X chromosome.
- **Option B**: "Males have one X chromosome and females have two X chromosomes" - This is correct. In all three organisms, males have one X chromosome, while females have two.
- **Option C**: "All males always have one Y chromosome in all three species" - This is not true for grasshoppers, as they do not have a Y chromosome; they have a different mechanism for sex determination.
- **Option D**: "The ratio of autosomes to sex chromosomes is the same in all three organisms" - This is misleading as the number of autosomes can vary between species.

3. **Conclusion**:
- The correct answer is **Option B**: "Males have one X chromosome and females have two X chromosomes." This reflects the similarity in sex determination across these species.

### Final Answer:
The similarity in sex determination in grasshoppers, humans, and Drosophila is that males have one X chromosome and females have two X chromosomes (Option B).

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