Cellulose-rich food substances are good source of roughage in human beings because

(i). Sodium (Na) is oxidised as it gains oxygen and oxygen gets reduced.  (ii). Copper oxide (CuO) is reduced to copper (Cu) while hydrogen (H2) gets oxidised to water (H2O).

Acidic : Human saliva, Lemon juice, milk, vinegar  Basic : Lime water, sea water, milk of magnesia.

(b) (i) and (iii) 

(i) In this reaction, sodium (Na) is changed into sodium oxide (Na2O). This is the addition of oxygen to sodittm. Since addition of oxygen is called oxidation, therefore, the substance...

a-(iii), b-(i), c-(iv), d-(v), e-(ii)

i. In the given reaction, sodium gets oxidised to sodium oxide (Na2O) and oxygen gets reduced. ii. In the given reaction, hydrogen getsoxidised to water and copper (II) oxide gets reduced...

i. Rancidity: The oxidation of oils and fats in foods resulting into a bad smell and bad taste is called rancidity. ii. To prevent rancidity, substances called ‘antioxidants’ are added to...

(i) Available in enormous amount in nature all the time. (ii) Easy to store and transport. (iii) It should be economical and easily accessible.

The correct answer is (1) Carotene is the source of retinal which is involved in formation of rhodopsin of rod cells. Retinal, a derivative of vitamin A, is the light-absorbing part...

(d) Biomagnification is the phenomenon of increasing concentration of compound in the tissue of organism, as the compound passes up a food chain, usually as a result of food intake....