The frog<span> heart has 3 chambers: two atria and a single ventricle. The atrium receives de-oxygenated blood from the veins (blood vessels) that drain the various </span>organs<span> of the body. The left atrium receives oxygenated blood from the lungs and skin...i believe this is right :)but im not sure but this is some of what one of my books say.</span>
Materials move within the cell 's cytosol by diffusion, and certain materials move through the plasma membrane by diffusion. ... Diffusion: Diffusion through a permeable membrane moves a substance from an area of high concentration (extracellular fluid, in this case) down its concentration gradient (into the cytoplasm). Water, carbon dioxide, and oxygen are among the few simple molecules that can cross the cell membrane by diffusion (or a type of diffusion known as osmosis ). Diffusion is one principle method of movement of substances within cells, as well as the method for essential small molecules to cross the cell membrane.The cell membrane controls what goes in and out by having protein channels that act like funnels in some cases and pumps in other cases. ... Active transport requires energy, because protein machines actively grab molecules on one side of the membrane and push them through to the other side
<span>The 4 categories of macromolecules include carbohydrates, proteins, lipids, and nucleic acids. Carbohydrates (grains and vegetables) are the largest group at the base of the pyramid, proteins (milk, poultry, eggs, nuts) follow up the pyramid while lipids (fats and oils) are the least amount at the summit of the pyramid. </span>
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</span><span>The aim of the pyramid is to recommend ideal rations for a healthy diet. Carbohydrates provide most of the energy needs for the days’ activities hence taking the largest portion. Proteins are used in building muscles, f0r nutrition, and body’s immunity hence required in lesser amounts compared to carbohydrates. Lipids help the body store energy since they have thrice as much energy as carbohydrates.They also a constituent of cell membranes and also help deliver vitamins. They are required in the least amount to avoid obesity and related illnesses such as cardiovascular <span>diseases</span></span>
The answer is c becuse they are not identical
