Answer:
The correct answer for the first question would be B) the respiratory and circulatory systems.
Respiratory system is a set of organs which help in exchange of gases in the body. They bring oxygen from outside into the body and release carbon dioxide from inside the body to outside world. The exchange of the gases takes place at alveolar site (or gills in aquatic animals).
The circulatory system then carries this oxygen (mixed in blood) from gas exchange site to all the cells of the body. In addition, it also brings carbon dioxide (waste product of cellular respiration) from all the cells to the gas exchange site (respiratory system).
The correct answer of the second question would be C)the digestive and circulatory systems.
Digestive system helps in breaking down of macro-molecules (such as starch, polypeptide, fats) into smaller units (such as glucose, fructose, amino acids) as well as absorption of the same.
Nutrients from the absorptive site (usually small intestine) are then transported to the entire body with the help of blood through capillaries and arteries that is, circulatory system.
