Which of the following is a pentameric immunoglobulin and is produced first in a primary response to an antigen?

Each antibody has $...A...$ polypeptide chains, $...B...$ small chains called $....C...$ chains and $...D...$ longer chains called $.E...$ chains

The antibody, therefore, is represented as $...F...$

Here $A$ to $F$ refers to

’Pathogens' are also known as

Definitions / Explanation : Pathogen & Immunity
 

Write a note on lymphoid organs.

Select the lymphoid organs from the given choices

$I$. Lymph node $II$. Thymus gland

$III$. Red bone marrow $IV$. liver

$V$. Spleen $VI$. Osteocytes

$VII$. Peyer's patches

The correct option with correct choices is