Find the Gender on the Basis of Genic Balance Theory?

Find the gender of the following combinations based on Genic Balance Theory:

1. 3A+XXX

2. 3A+XXY

3. 2A+XX

4. 2A+XY

5. 3A+XX

6. 3A+XY

7. 2A+XXX

8. 2A+XXY

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What Is Genic Balance Theory?

C.B. Bridges in 1922 proposed the Genic Balance Theory for sex determination while working on his experimental model, Drosophila.

Like mammals, XX sex chromosome determines female character and XY as males in Drosophila. However, unlike humans, Y chromosome is not responsible for maleness in Drosophila, as Y chromosome is heterochromatic in nature and thus not active in sex determination.

According to Bridges, sex determination in Drosophila depends on the X/A sex index ratio. Following are the sex index ratios for maleness and female characters:

If X/A = 1.0 it means normal female
If X/A = 0.5, it means normal male
If X/A = <0.5, it means super male
If X/A = 0.5 to 1.0, it means intersex
If X/A = >1.0, it means super female

For example, 3A+XXX: X/A = 3/3 = 1.0 => Normal female
                     2A+XO: X/A = 1/2 = 0.5 => Normal male

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