Answer:
Explanation:
In a lake, oxygenic phototrophs produce new organic material as well as O₂. If primary production rates are very high, the resultant excessive organic matter production can lead to bottom-water O₂ depletion from respiration and the development of anoxic conditions. This in turn stimulates anaerobic metabolisms, including anaerobic respirations and fermentations.
Organic matter that is not consumed in surface layers sinks to the depths and is decomposed by anaerobes.
<span>Facilitated diffusion
Diffusion
occurs because of the movement of molecules from the region of higher
concentration to the region of lower concentration. This movement of
molecules occurs due to a thermal motion. Diffusion normally occurs
between two compartments having difference in concentration. In case of
fluid it moves from the region of higher concentration to the region of
concentration until a balance is reached. The process of diffusion is
very important for the humans as well. The oxygen that humans breathe in
gets diffused with the blood.<span> </span></span>
Answer:
Platyhelminthes
Explanation:
Platyhelminthes (phylum Platyhelminthes), also known as flatworms, are bilaterian, unsegmented and soft-bodied invertebrates. Platyhelminthes are hermaphroditic organisms with internal fertilization. In addition, this group shows a series of characteristics including 1-a ladder-like nervous system, 2-presence of parenchyma in the body cavity, and 3-flame cells, i.e., specialized excretory cells that function like a kidney. Platyhelminthes can be divided into three groups: Turbellaria (generally found in freshwater), Trematoda (generally parasitic), and Cercomeromorpha (exclusively parasitic).
