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:
At the very end of the cladogram at the very top of a clade in the middle of a clade along the main trunk of the cladogram
Answer:
a. allow a variety of molecules to cross the cytoplasmic membrane
Explanation:
The cells have different molecules in its membrane. As a membrane the main function of it is to regulate the income and outcome of substances that the cell needs or the cell has like some wastes.
Some of these molecules can be some proteins like the permeases, that is going to regulate the solutes that can enter the cell, but since they are non specific, that means that can not make the difference among one carbohydrate and another (as an example).
Answer:
Sponge; Radial Symmetry; Endoskeleton; Absent Appendages; Absent Segmentation
Cnidarians; Radial Symmetry; No Skeleton; Non-Jointed Appendages; Absent Segmentation
Roundworms; Radial Symmetry; No skeleton; Absent Appendages; Absent Segmentation
Annelids; Radial Symmetry; No skeleton; Absent Appendages; Present Segmentation
Mollusks; Bilateral Symmetry; Exoskeleton; Non-Jointed Appendages; Absent Segmentation
Arthropods; Bilateral Symmetry; Exoskeleton; Jointed Appendages; Present Segmentation
Echinoderms; Bilateral Symmetry; Endoskeleton; Non-Jointed Appendages; Absent Segmentation
Vertebrates; Bilateral Symmetry; Endoskeleton; Jointed Appendages; Absent Segmentation
