In the development of dogs, monkeys and dolphins, nourishment and oxygen are provided by the mother to the fetus through the

The umbilical cord.

During the gestation period of most mammalian species like the digs, monkeys, dolphins, cats, cows, horses and other related organisms they develop the so-called umbilical cord. This tissues and tube-like structure helps the offspring develop by delivering nutrients from the mother to the ongoing fetus. 

The answer would be true

That is true tge cactus as a structural adaptation to its envirinment has it leaves reduced to spines. but this doesnt mean it cant produce food it produces food because of the presence of chlorophyll in its stem