Enamel of teeth is secreted by `:-`

Enamel on teeth is

The enamel part of tooth is secreted by

The enamel part of tooth is secreted by

While the enamel of teeth is formed from underline("mesoderm") the dentine is formed from endoderm.

The part of a teeth that is covered by enamel.

Crown of teeth is covered by (a) dentine (b) enamel (c) both (i) and (ii) (d) none of these

White enamel of our teeth is

Assertion: The deficiency of fluoride in drinking water cause disease such as tooth decay etc. Reason: The F^(-) ions make the enamel on teeth much harder by converting hydroxyapatite, the enamal on the surface of the teeth, into much harder fluorapatite.

The concentration of fluroide ions in drinking water upto 1 ppm make the enamel on teeth much harder by converting ul(x) into fluorapatite. What is ul(x) ?