Answer:
Nutrient pollution is the process where too many nutrients, mainly nitrogen and phosphorus, are added to bodies of water and can act like fertilizer, causing excessive growth of algae. Nutrients can run off of land in urban areas where lawn and garden fertilizers are used
Explanation:
The question is incomplete. Th ecomplete question is as following:
All of the following protect the skin and mucous membranes from infection EXCEPT
A) multiple layers of cells.
B) tears.
C) saliva.
D) HCl.
E) the "ciliary escalator."
Answer: D) HCl.
Explanation:
- The epidermis, the outer layer of the skin provides waterproofing and serves as a barrier to infection and other laers also sustain any type of injury.
- Tears wash out foreign bodies which enter the eye. In addition, tears contain a substance called lysozyme which has an antibacterial function and works to prevent microbial invasion and infection.
- Saliva protects against infection, especially via the innate immune system. This mechanism is an important first-line protection against bacterial and viral infection
- The mucociliar escalator is within the conducting airways and is composed of mucus and cilia that transfer the mucus up and out of the lungs where it can be removed by coughing or swallowing,
Whereas HCL helps in the digestion process.
Hence, the correct option is D.
Cell is limited in size for many reasons. Cells wouldn't be respire effectively if it were too large, because the surface area to the volume ratio would be too small.
The other thing is that if the cell were too large, it would be difficult for it to move nutrients and waste products in and out of the cell. So, cells are limited in size.
Intestinal Bacteria is known to :
- Make vitamins we use
- Help our immune system function correctly
- Make anti-inflammatory chemicals
- Help to keep us lean (possibly)
- Digest proteins, lipids, and carbohydrates in our food
