being unhealthy has a negative impact on an organism & the unhealthy diet of a mother during pregnancy has a negative impact on the embryo ->  the unhealthy diet of a mother during pregnancy causes the embryo to be unhealthy  the unhealthy diet of a mother during pregnancy causes the embryo to be unhealthy & if a source of food is unhealthy then the organism consuming that food will be unhealthy ->  the unhealthy diet of a mother during pregnancy is harmful to the embryo because the mother is a source of food for an embryo through the placenta  the unhealthy diet of a mother during pregnancy is harmful to the embryo because the mother is a source of food for an embryo through the placenta & something recieves something else from a source of that something else -> the unhealthy diet of a mother during pregnancy is harmful to the embryo because the receives food from its mother through the placenta