What are primary lymphoid organs?

Select the correct option to fill up the blanks. (i) Diseases which are easily transmitted from one person to another, are called ______ diseases. (ii) In human body, parasite of malaria initially multiplies within the ____ and then attack the ______. (iii) _____ is the yellowish fluid secreted by mother during the initial days of lactation. (iv) _____ and ____ are the primary lymphoid organs.

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

What are secondary lymphoid organs?

What are lymphoid organs?

Which of the following is the primary lymphoid organ?

…………. Is a primary lymphoid organ of birds.

Assertion (A): spleen is a primary lymphoid organ Reason (R ):Primary lymphoid organs trap antigen and destroy them.

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