what will happen if the respiratory and circulatory systems fail to transport nutrients, gases, and other molecules

Then your blood becomes useless.

Explanation:

The blood in your body contains many hemoglobin which contains iron. Iron carries oxygen around your body, and keeps strength in you to continue to live. If the respiratory systems fail, and they cannot transport these nutrients, gases, and other molecules, your blood will directly be influenced, which means you will most likely die.

roses are red,

violets are black,

for what you said,

i hope you sit on a big fat tack.