Answer:
A. humans going underwater and exhaling
Explanation:
The dissolved oxygen in water refers to the amount of oxygen that is found in water. However, there are various ways that oxygen dissolves in a body of water, these includes;
- Photosynthesis of aquatic plants: Oxygen is the waste product of the photosynthetic process carried out by green plants. Hence, when aquatic plants undergo photosynthesis, oxygen from them tend to dissolve into water.
- Diffusion from the atmosphere: Oxygen from air or atmosphere also dissolves in water
- aeration as water moves over rocks and debris, and from wind and waves
However, humans do not exhale oxygen but carbon dioxide, hence, it is not a source of dissolved oxygen
Effector muscles
hope it helps
Pressure with Height: pressure decreases with increasing altitude. The pressure at any level in the atmosphere may be interpreted as the total weight of the air above a unit area at any elevation. At higher elevations, there are fewer air molecules above a given surface than a similar surface at lower levels.
Answer:
Sea anemones are marine predatory animals. They are like a terrestrial flowering plant due to their colorful appearance. They are coming under the phylum cnidaria.
Sea anemones are found in different forms called a polyp. It has a columnar trunk, on the top of the trunk an oral disc and centrally placed mouth. The mouth is surrounded by tentacles.
Sea anemones have a gastrovascular cavity that serves as stomach. This cavity has one opening both meant for mouth and anus.
Sea anemones are capable of changing their shape and lives on the mud, holding it by pedal disc.
Polychaetes are segmented worms. Each segment of the body bears parapodia. It helps them in locomotion. There are different types of polychaetes, tube-dwelling polychaetes are one of them.
Tube - dwelling polychaetes make tubes to protect their soft bodies.
They don't have parapodia but some special anterior structures for feeding. The tubes are made from calcareous materials.
