'Vaccination' was invented by

Which of the following is/are inconsistent with a healthy individual?
$(1)$ Increased efficiency
$(2)$ Higher productivity
$(3)$ Increased longevity of people
$(4)$ Increase in infant and maternal mortality rates

Assertion: Thick cuticle is mostly present in disease-resistant plants.
Reason: Disease-causing agents cannot grow on cuticle and cannot invade the cuticle.

Streptomycin was first isolated in $1944-45$ by

The polypeptide chains in the structure of an antibody are held together by .........

An insect regarded as the greatest mechanical carrier of disease is