Phycoerythrin is a red pigment found in red algae (Rhodophyta), masking the green chlorophyll. Fucoxanthin is brown (brown algae), chlorophyll is green, carotene is orange/yellow. Phycoerythrin absorbs blue light, allowing red algae to live in deeper waters.
Explanation:
The oblique entry of the ureters into the bladder creates a valve-like effect, preventing reflux. The urethral sphincter controls urination.
Explanation:
Mature human RBCs have a lifespan of approximately 120 days, after which they are phagocytosed by macrophages in the spleen and liver. They lack nuclei and organelles, thus cannot repair themselves. New RBCs are produced in the bone marrow at a rate of about 2 million per second. Erythropoietin stimulates RBC production.
Explanation:
Jonas Salk developed the inactivated polio vaccine (IPV) in 1955, which was the first effective vaccine. Albert Sabin later developed the oral polio vaccine (OPV). Pasteur rabies, Jenner smallpox.
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