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
A. Cell membrane
the plasma membrane, also called the cell membrane, is the membrane found in all cells that separates the interior of the cell from the outside environment.
The alteration in the protein structures can take place due to many reason. Once, the structure of the protein is altered, it cannot perform its function, as it cannot bind to the site for which it is designated.
Most of the biological processes use proteins in their completion. In case, the protein cannot perform its function, the metabolic process associated with that particular protein may stop and cause severe illness.
The heat can cause the denaturation of the proteins. The proteins are made up of amino acid sequences, the heat can break the peptide bond present between the amino acids present in protein, which can result in alteration of protein.
Hence, the correct answer is option (d). all of them are correct.