Alveolar walls are thin to enable the quick passage of oxygen in and out of the lungs. The lungs works hand-in-hand with the heart and also is responsible in converting blood that's de-oxygenated into an oxygenated blood that is usable by the organ systems of the body. The alveolar walls are also designed to have thin membranes so that it can expand and constrict quickly allowing us to breather properly.
Answer:
The marine clamworm, Nereis, is carnivorous therefore its digestive system differs from that of the herbivorous earthworm, Lumbricus. The mouth and jaws are retractable (Figure 8, 9). If the jaws are retracted, cut along the midline of the pharynx and pull the jaws out with a pair of forceps.
Explanation:
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D would be the correct answer
- Energy Production (providing energy)
- Energy Storage
- Breakdown of fatty acids
- Building Macromolecues