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.
The correct answer is option A , C and D
The earths material is recycled and this can be visualized from the different chain cycles such as nitrogen cycle, carbon cycle , sulphur cycle, water cycle etc. These basic components which constitute all the matter existing on earth are continuously recycled and reused. Likewise the energy obtained from sun is neither created nor destroyed; it is only converted from one form of energy to the other form. Such as heat energy obtained from sun is converted into kinetic energy when it converts water into water vapor.
Vertical stairs :P: W = (20 N) * (6.0 m) * cos (0 degrees) = <span>120 Joules
At 45 degrees: W = (20.0 N) * (6.0 m) * cos (45 degrees) =
(20N) * 6m) * (</span><span>0.707106781) = 84.853 Joules</span>
The appropriate answer for this one is C. Cancer cells divide uncontrollably and therefore the cell cycle would be continuously divide. To add, there is a term known as terminally differentiated cells. These cells that never enter the cell cycle again, meaning they stay in G0 and never divide. However, some cells can be triggered to depart G0 and re-enter G1, which permits them to divide again.
here is the awnsers hope it helps you...
Answer:
relaxes
Explanation:
Acetylcholine is the substance responsible for the transmission of nerve impulses from pre-postganglionic neurons, in the ganglia of the autonomic nervous system. At the level of the parasympathetic nervous system, the transmission between the postganglionic neuron and the effector organ also mediates. In addition, it is the mediator of the nerve transmission of the terminal motor plate.
There are large differences in the effects that Acetylcholine triggers at different cholinergic transmission sites
Intra-arterial injection near Acetylcholine produces muscle contraction similar to that caused by motor nerve stimulation. Decreased resting potential in isolated intestinal muscle and increased frequency of spike production, accompanied by increased tension. In the cardiac conduction system, nodes S-A and A-V, it produces inhibition and hyperpolarization of the fiber membrane; and pronounced decrease in depolarization speed. Central regulation of extrapyramidal motor function. Exciting effect of the basal ganglia that counteracts the inhibitory action of Dopamine. Although cholinergic innervation of blood vessels is limited, cholinergic muscarinic receptors occur in sympathetic vasoconstrictor nerves. The vasodilator effect on isolated blood vessels requires the presence of an intact endothelium. The activation of muscarinic receptors causes the release of a vasodilator substance - <u>relaxing factor derived from the endothelium - that diffuses to the smooth muscle producing </u><u>relaxation</u><u>.</u>
