Final answer:
The chances of a mother having twins can be influenced by hereditary factors, with evidence suggesting that the mother's side of the family plays a stronger role. This is due to genes responsible for multiple egg release and factors affecting hormone levels and the reproductive system.
Step-by-step explanation:
The chances of a mother having twins can be influenced by both her own genetic background and the genetic background of the father. However, in terms of hereditary factors, there is evidence to suggest that the mother's side of the family plays a stronger role in increasing the likelihood of having twins.
One reason for this is that the ability to release more than one egg during ovulation, which is necessary for conceiving twins, can be passed down through generations on the mother's side. This is because the genes responsible for the release of multiple eggs are located on the X chromosome.
Another factor that contributes to the increased likelihood of twins in a mother's family is hereditary factors that affect the hormone levels and reproductive system. These factors can be influenced by genes passed down from the mother's side.