Correct the following statements if they are false (without changing the first word).

(i) DDT is an antiseptic. ………………………………

(ii) Penicillin is a disinfectant. ……………………………

(iii) Disinfectants are applied on the body. ……………………………………………………………

(iv) Deodorants are both antiseptic as well as disinfectants. ……………………………………………

(v) Alexander Fleming discovered the first sulphonamide. ……………………………………

(vi) Antibiotics cannot be made synthetically. ……………………………………

(vii) Sulphonamides are now rarely used. ………………………………………………

(i) The correct statement is: “DDT is an insecticide”

Explanation:

The full form of DDT is Dichlorodiphenyltrichloroethane. It has insecticidal properties. It was extensively used in agriculture.

(ii) The correct statement is “Penicillin is an antibiotic.”

Explanation:

Penicillin is a group of antibiotics. It is used against staphylococci and streptococci. Both of these are bacteria. Streptococci are usually found in the throat region and on the skin. Staphylococci are present on the skin.

(iii) The statement is true

Explanation:

Disinfectants are supposed to be used on a surface and are not meant for ingestion.

(iv) The statement is true

Explanation:

Antiseptics are used to used to clean a surface - to remove any germs. Disinfectants are used to prevent entry of germs. Deodorants act as both and serve both purposes.

(v) The correct statement is “Alexander Fleming discovered the first antibiotic.”

Explanation:

Alexander Fleming discovered Penicillin which is the first antibiotic. It is used against staphylococci and streptococci. Both of these are bacteria. Streptococci are usually found in the throat region and on the skin. Staphylococci are present on the skin.

(vi) The correct statement is “Antibiotics can be made synthetically.”

Explanation:

Antibiotics can be made synthetically. They are of two types - Narrow Spectrum and Broad Spectrum. The working speed of synthetic antibiotics is greater than that of natural antibiotics. For example, sulphonamides come under the category of synthetic antibiotics.

(vii) The statement is true

Explanation:

Sulphonamides have been found to have a huge range of side effects. These chemicals also need to be carefully administered. Hence, they have been replaced by better drugs.