Which of the following is a fungal disease? MCQ with Answer and Explanation

Explanation:
Hemoglobin is an iron-containing metalloprotein in erythrocytes that binds oxygen reversibly, forming oxyhemoglobin. Each molecule has four heme groups, each binding one O₂. Collagen is a structural protein, insulin a hormone, fibrinogen a clotting protein. Hemoglobin also carries some CO₂ and buffers blood pH.

Explanation:
The Central Dogma of molecular biology was proposed by Francis Crick in 1958. It describes the fundamental flow of genetic information within a biological system: DNA is transcribed into RNA, and RNA is translated into protein. The flow is typically unidirectional: DNA -> RNA -> Protein. While exceptions exist (like reverse transcription in retroviruses, where RNA -> DNA), the central dogma remains the core principle of gene expression.

Explanation:
Primary lymphoid organs are where lymphocytes are produced and mature. Bone marrow (where B cells mature) and thymus (where T cells mature) are primary. Secondary lymphoid organs, like spleen, lymph nodes, and tonsils, are where mature lymphocytes encounter antigens and initiate immune responses. The bone marrow also is the site of hematopoiesis.