Why is it that diploid offsprings produced sexually are neve

Why is it that diploid offsprings (produced sexually) are never genetically identical to their parents?

Solution

Most of the diploid organism are found to sexually reproduce which involves the formation and maturation of gametes.

Now during the formation of gametes(meiosis), a process called crossing over takes place. This corssing over is only possible if there are two copies of DNA molecule, which is present in diploid organism.

The Corssing over process is what generates \"Variations\" in the offsprings from the parents. This is basically due to differnet DNA sequence found in the parent and the offspring. And the differnece is sequence arises from Crossing over during meiosis.

Now in case of haploid organisms, reproduction takes place via mitosis(generally). This does not involve crossing over,. Moreover is does not have two copies of genes which would result in any kind of variation in the DNA sequence between the parent and the offspring.