If the teeth are not cleaned regularly, they become covered with a sticky yellowish layer W of food particles and bacteria. Since layer W covers the teeth, the alkaline liquid X secreted by glands Y inside the mouth cannot reach the teeth surface to neutralize the acid formed by the action of organisms Z on sugary food, and hence tooth decay sets in.(a) What is W known as?(b) What is (i) X, and (ii) Y?(c) What are organisms Z?(d) State one way of removing layer W from the teeth.
(a) W is the dental plaque.
(b) (i) X refers to the saliva.
(ii) Y refers to the salivary glands.
(c) Organisms Z are bacteria.
(d) One way of removing the layer of dental plaque (W), can be by regular brushing of teeth.
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