Answer:
Most cells within planarians tend to be very close to their gastrovascular cavity, in addition to their external environments. Also, planarians have the ability for oxygen and carbon dioxide to diffuse through the cells on their body walls: this makes it unnecessary for these varieties of flatworms to need a dedicated bodily system.
I think the deficiency of dedicated respiratory and circulatory systems in Planarians does not cause a problem because none of their cells are far removed from the gastrovascular cavity or from the external environment. Planarians are free-living flatworms and form the class Turbellarians in the Phylum Platyhelminthes. Flatworms have three tissue layers, that is the ectoderm, mesoderm, and endoderm.
hope this helps!!!!!....
Explanation:
The right option is a.colostomy
A colostomy is a surgical
procedure in which an opening is made between the colon and body surface. During
colostomy, an opening is made by bringing one end of the large intestine or
colon out through the abdominal wall using incision. Colostomy is performed
when the large intestine is blocked or damaged and when a ruptured colon causes
an abdominal infection. The procedure may be short-term or permanent.
To protect them from ultraviolet rays from the sun.
They are made up of nitrogen bases,sugars,and a phosphate group