The combination of a heart, arteries, veins, and capillaries is A. CELL

B. an organ system

C. organism

D. tissue

the answer should be blood vessels in the cell

so practically it should be A. cell

pathogens is the answer

a mother eats twice as much to support her growing fetus

limiting sugar intake in a mother with gestational diabetes, switching from diving to swimming.   depending on whether the patient is normal weight, over weight or gain will differ depending on that.