Give below are some human organs . Identify one primary and one secondary lymphoid organ . Explain its role . Liver , thymus, stomach , thyroid , tonsils .

Which is the primary lymphoid organs of birds?Mention its location and role.

Explain the structure are role of thymus in primary lymphoid organ.

Given below are some differences between primary air pollutants and secondary air pollutants. Which one of the following is an incorrect difference ?

Given below are pairs of disease and causative organisms. Which one out of these is not a matching pair and why? Filariasis : Wuchereria Ringworm : Ascaris AIDS : Human Immuno Virus Malaria : Plasmodium

(a) The picture depicts a theory of use or disuse of organs. Name it. (b) Name the scientist who proposed it. ( c) Give one example and explain the theory with its help. Why was this theory disproved?

The figure given below shows a small part of human lung where exchange of gas take, place. In which are of the options given below, the one part A, B, C and D is correctly, identified along with its function?

Given below is the diagrammatic representation of one of the categories of small molecular, weight organic compounds in the living tissues.Identify the categor shown and the one blank component 'X' in it: .