Answer:
The veins and arteries encounter differences in the pressure of the blood flow. As a consequence, these differences are seen in the composition of the vessels. The arteries encounter with a pressure wave as blood gets pumped from the heart. This can be experienced as a pulse. Due to this pressure, the arteries' walls are much thicker in comparison to those of the corresponding veins.
Thus, arteries appear to exhibit more uniform shape, they seem to be more circular in shape in comparison to veins. Veins do not encounter with the pressure waves like the arteries do. Thus, they do not require to be structurally strong. The vessels' walls of veins are thinner in comparison to arteries and do not exhibit much tunica media.
The correct answer is contractile vacuole.
The contractile vacuole is a water bubble present in the endoplasm of the amoeba. The role of the contractile vacuole is same as the role of the central vacuole in plants.
The contractile vacuole stores the water and the waste material of the cell, along with some mineral and other substance, so, they help in the maintenance of the osmolarity. In case, the walls of the contractile vacuole is damaged, the cell may burst out.
Idk honestly that’s some bs I don’t even know what physical means
If we take a look at the phylogenetic tree of bears presented in the picture above, we can see that the branch number one is the common ancestor to all living bear species, which means that the whole group has a uniform origin. and the
phylogenetic tree has a root. Therefore, the group is monophyletic, not <span>polyphyletic ( meaning that the whole group has the same origin) and not paraphyletic ( there is no group that has been excluded from the tree).</span>
