Question

2
When a person eats sugary food, then organisms A present in his mouth act on sugar to produce a substance B. The substance B first dissolves the calcium salts from the top part C of the tooth and then from its middle part D forming holes E. These holes ultimately reach the part F in the lower part of tooth which contains nerves and blood vessels. The substance B irritates the nerve endings inside the tooth causing toothache.
(a) What are (i) organisms A, and (ii) substance B?
(b) What are (i) part C, and (ii) part D, of tooth known as?
(c) By what name are the holes E in the tooth known?
(d) Name the part F of the tooth.
(e) What will happen if organisms A reach part F of the tooth known?

Answer 1

Answer:

After recovering from infection of ringworm, Reena thought that all fungi are harmful for human kind, as these spoil food and cause various diseases. But her elder sister told him that not all fungi are harmful, some are quite useful such as in making bread, vitamins, Medicines (antibiotics) and in decomposing organic wastes.

(i) Name any fungus which is used in bread making.

(ii) Name any fungus which is the source of some medicine.

​(iii) What ecological benefit is shown by fungi?