# A tetra-hybrid plant produces fruits of 1 kg while minimum weight is 400 g. What will be the maximum weight of a fruit ? (1) 600 g (2) 1600 g (3) 1200 g (4) 1800 g

Apr 23, 2018

$\text{1600 g}$

#### Explanation:

This is a question of Polygenic inheritance. When all the alleles are recessive, we get minimum weight condition and when all the alleles are dominant, we get maximum weight condition.

In a tetrahybrid condition $\left(\text{AaBbCcDd}\right)$, the weight of the plant is $\text{1000 g}$, i.e minimum weight $+$ weight due to four dominant alleles.

Therefore, the weight of four dominant alleles $= \text{1000 g" - "400 g" = "600 g}$.

Now, the weight due to $8$ dominant alleles $= \text{minimum weight" + 2 xx "600 g" = "400 g" + "1200 g" = "1600 g}$.

Let me know if you didn't understand this properly.
P.S. I also gave this test yesterday!