The cardiovascular system transports oxygen and nutrients to the cells and transports waste away from the cells
Some causes could be the mother smoking, drinking, doing drugs etc. Or even simply her body doesn’t fully accept the baby growing inside her so it acts out against it. Sounds strange but it happens. Also if the mother is sick with Zika or another virus, it can harm the baby’s growth.
Answer:
In species with polyploid, there are more chromosomal sets than in diploid one. Becouse there are more chromosomal structures available, events like mutation, recombination, DNA lose, are more probable to occur.
As the generations pass, the accumulation of these changes tend polyploid to speciation.
The HCG hormone is the answer possibly
