In which of the sex determination both male and female same number of chromosomes ?

Options

A. XY type
B. ZO type
C. XO type
D. Both (1) & (3)

Answer

To answer the question "In which of the sex determination both male and female have the same number of chromosomes?", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Chromosome Types**:
- In sex determination, chromosomes can be categorized into autosomes and sex chromosomes (also known as allosomes).

2. **XY Sex Determination**:
- In the XY sex determination system (found in humans and many other organisms), males have one X and one Y chromosome (XY), while females have two X chromosomes (XX).
- Both males and females have a total of 23 pairs of chromosomes, which means they both have the same number of chromosomes (46 total).

3. **Drosophila Example**:
- In Drosophila (fruit flies), the sex determination system is also XY, where males have XY and females have XX.
- Drosophila have a total of 8 chromosomes (4 pairs), and both males and females have the same number of chromosomes (8 total).

4. **Other Sex Determination Systems**:
- In ZW sex determination (found in birds), females have ZW (two different sex chromosomes), while males have ZZ (two of the same sex chromosomes). Here, the number of chromosomes is not the same.
- In X0 sex determination, males have one less chromosome than females (X0 for males and XX for females), which also results in a different number of chromosomes.

5. **Conclusion**:
- The XY sex determination system in both humans and Drosophila is an example where both males and females have the same number of chromosomes. Therefore, the correct answer to the question is the XY type of sex determination.

### Final Answer:
The sex determination system in which both male and female have the same number of chromosomes is the **XY type** (found in humans and Drosophila).

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