52. which results in the graph in figure 7-12 are more likely to be accurate, those represented by line a or line b? why?
53. what could account for the differences in lines a and b in the graph
54.

Once an egg cell is fertilized by sperm, the cell then, as the embryo develops, it receives nourishment and eliminates wastes by transferring substances from its blood to its mother's blood. a. becomes a fetus immediately and exits the womb b. begins to divide and implants itself in the wall of the uterus c. remains in the uterus without dividing for several months d. travels back to the ovaries until the fetus is developed