The scientist who proposed the 'lock and key' model of enzyme action was: MCQ with Answer and Explanation

Explanation:
Hematopoiesis is the production of formed elements of blood (red cells, white cells, platelets) from hematopoietic stem cells in the bone marrow. Hemolysis is RBC destruction, hemostasis is stopping bleeding, hematuria is blood in urine. Erythropoietin stimulates RBC production.

Explanation:
Excretion is the elimination of nitrogenous waste products (urea, uric acid, ammonia) and other metabolic wastes from the body, primarily by the kidneys. Digestion is breakdown of food, circulation is transport, respiration is gas exchange and energy release. Excretion maintains homeostasis of body fluids and prevents toxic accumulation.

Explanation:
Robert Hooke, in his 1665 book 'Micrographia', described observing dead cork tissue under a microscope and coined the term 'cell' for the small, box-like compartments he saw. Antonie van Leeuwenhoek, using his superior handcrafted single-lens microscopes in the 1670s, was the first person to observe and describe living, single-celled microorganisms, which he called 'animalcules'. Charles Darwin proposed the theory of evolution by natural selection; the cell theory was proposed by Schleiden and Schwann. Thus, statements 1 and 2 are correct.