The scientist who discovered the blood groups (ABO system) was: MCQ with Answer and Explanation

Explanation:
Phytoplankton, including cyanobacteria, diatoms, and dinoflagellates, are microscopic photosynthetic organisms that drift in oceans and freshwaters. They are primary producers responsible for about half of global oxygen production. Brown, red, and green macroalgae also contribute but phytoplankton are the primary oxygen producers.

Explanation:
A virus is an obligate intracellular parasite. The basic structure of a virus particle, or virion, consists of genetic material (either DNA or RNA, but never both) enclosed in a protective protein coat called a capsid, made of subunits called capsomeres. Some viruses also have an outer lipid envelope derived from the host cell membrane.

Explanation:
Hemoglobin is a red, iron-containing protein in red blood cells (erythrocytes) that reversibly binds oxygen to form oxyhemoglobin. Each molecule has four heme groups, each binding one O₂ molecule. Hemocyanin (copper-based) is found in some invertebrates. Myoglobin stores oxygen in muscles. Cytochromes are electron carriers in respiration. Hemoglobin also transports CO₂ as carbaminohemoglobin.