Why are tigers and lions able to mate to produce cubs, but those cubs would not be able to go on to produce any off spring

Tigers and lions able to mate to produce cubs,but those cubs would not be able to go on to produce any off spring because their sex chromosomes do not match.

Explanation:

Tigers and lions mate to produce ligers and tilons but they do not produce viable sperms or egg.In an organism there are two copies of chromosomes present in the somatic cells.But in case of sex cells they receive each set from mother and father. which they duplicate and divide during formation of gametes via meiosis.in such case if the sets are recieved from two different species then after pairing a mismatch will occur in the gene loci.For example, a eye colour gene may correspond to a paw length gene.Thus the gametes when produced will not be viable.