Flatworms use a system of canals and tubes with the as their excretory organ.

Flatworms use a system of canals and tubes with the mouth as their excretory organ. They belong to the Phylum Platyheminthes. Flatworms can be cut in half creating two individuals by binary fission. Binary fission is a type of asexual reproduction in which the offspring has the same features and characteristics of the parent. During binary fission, the DNA replicates into two and goes at the end of each membrane. And then the cell membrane divides into two daughter cells. Then cytokinesis follow.

False

Explanation:

We breath the carbon dioxide out and oxygen. The oxygen is required by the cell to produce energy while carbon dioxide is produced by the cells as byproduct and need to be exhaled from body. This exchange of gases is occur in lungs.

The membrane through which gaseous exchange occur in lungs is called as respiratory membrane or respiratory surface and is composed of the of alveolar epithelial cells and pulmonary capillary endothelial cells. Epithelial cells represents the cell on the outer surface of alveoli and endothelial cells represents the cells on the inner surface of capillary while pulmonary capillaries indicates the capillaries present in lungs.

So there is air present in alveoli on side of respiratory membrane and blood present on the other side of membrane in capillaries. The gases (Co2 and O2) diffuses according to difference in their partial pressure in alveoli and pulmonary capillaries.