Marine ecosystems cover approximately 71% of the Earth's surface and contain approximately 97% of the planet's water. They generate 32% of the world's net primary production. They are distinguished from freshwater ecosystems by the presence of dissolved compounds, especially salts, in the water. Approximately 85% of the dissolved materials in seawater are sodium and chlorine. Seawater has an average salinity of 35 parts per thousand(ppt) of water. Actual salinity varies among different marine ecosystems.
A classification of marine habitats.
Marine ecosystems can be divided into many zones depending upon water depth and shoreline features. The oceanic zone is the vast open part of the ocean where animals such as whales, sharks, and tuna live. The benthic zone consists of substrates below water where many invertebrates live. The intertidal zone is the area between high and low tides; in this figure it is termed the littoral zone. Other near-shore (neritic) zones can include estuaries, salt marshes, coral reefs, lagoons and mangrove swamps. In the deep water, hydrothermal vents may occur where chemosynthetic sulfur bacteria form the base of the food web.
Classes of organisms found in marine ecosystems include brown algae, dinoflagellates, corals, cephalopods, echinoderms, and sharks. Fishes caught in marine ecosystems are the biggest source of commercial foods obtained from wild populations.
Environmental problems concerning marine ecosystems include unsustainable exploitation of marine resources (for example overfishing of certain species), marine pollution,climate change, and building on coastal areas.
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Mouth- moistening the mechanical digestion of food
Liver- aiding in chemical digestion of fats
Small intestine- chemical digestion and absorption of nutrients
Stomach- mechanical and chemical digestion of food with acids and enzymes
Large intention- absorption of water and compaction of indigestible material for elimination
Pancreas- secreting the enzymes lipase, trypsin and amylase.
Explanation:
We have attached a figure that shows the diagram of the given equation.
We need to find how many angles are alternate exterior angles with angle 5?
We know that an exterior angle is the angle that is made outside of the shape and an alternate angle is the angle opposite of a transversal line of another angle.
From the figure, 8, 7, 9, 10, 12, and 11 are the angles that are on the same transversal. 8, 7, 9, 10, and 12 are just exterior. It means that 11 is the alternate exterior of angle 5. So, only one angle is alternate exterior angles with angle 5.
