It is The multicellular part
Answer:
d. Fluoride becomes incorporated into the crystalline structure of teeth, making them less susceptible to decay
Explanation:
Dental caries results when cariogenic (caries-causing) bacteria metabolize carbohydrates or sugars present in the mouth for their energy needs, producing organic acids as byproducts, thus lowering the pH of the plaque biofilm.
The hydroxyapatite of tooth enamel is composed mainly of phosphate ions (PO₄³⁻) and calcium ions (Ca⁺). Under normal conditions, there is a stable equilibrium between the calcium and phosphate ions in saliva and the crystalline hydroxyapatite. At low pH (acidic conditions), there is a shift in equilibrium resulting in the dissolution of hydroxyapatite from tooth enamel, a process known as demineralization. A reverse process called remineralization (the process of incorporation of minerals in tooth enamel) occurs when the saliva, acting as a buffer elevates pH. When equilibrium is shifted to favor continued demineralization, dental caries results.
However, when fluoride is present in saliva, fluorapatite, rather than hydroxyapatite, forms during the remineralization process as fluoride ions replace hydroxyl groups in the formation of the apatite crystal lattice.
Fluorapatite is less soluble than hydroxyapatite making it more resistant to demineralization, even under conditions of low pH. Thus, fluoride acts as an effective anticaries agent.
Answer:
True
Explanation:
In Croatia, Czech Republic, Hungary, Lithuania, and Poland, money for forest protection comes from fines from the illegal cutting of trees and from fees for legal permits to do so. In addition, large areas in Eastern Europe have been set aside as protected areas.
Answer:
The weaker weevils were killed, and Farmer Fran accidentally caused only pesticide-resistant weevils to survive.
Explanation:
Over the years, pests builds resistant as a result of continuous exposure to a particular pesticides, hence; those with strong immunity were able to pass across the gene to the younger generation and with time they became used to it and makes it less or not effective on them.
