Explain lymphoid organs?

The primary lymphoid organs are

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.

Lymph node is primary lymphoid organ.

Read the following statements regarding spleen and select the correct option. (i) Spleen is a large oval-shaped organ which mainly contains lymphocytes and phagocytes. (ii) Spleen is a large reservoir of erythrocytes. (iii) Spleen is a primary lymphoid organ. (iv) spleen acts as a filter of the blood by trapping blood-borne microorganisms.

Explain vestigial organ.

Organic evolution refers to a change in diversity and ......... in populations of organisms.

Meiosis in diploid organisms results in

Which of the following is not a lymphoid tissue ?

Who explained organic evolution as the descent with modification?