CTET 2 Math and Science Feb 2014 Paper

The excretory system is a passive biological system that removes excess, unnecessary materials from an organism, so as to help maintain homeostasis within the organism and prevent damage to the body.The excretory system is a close partner with both the circulatory and endocrine system. The circulatory system connection is obvious. Blood that circulates through the body passes through one of the twokidneys. Urea, uric acid, and water are removed from the blood and most of the water is put back into the system.The urinary bladder is the organ that collects urine excreted by the kidneys prior to disposal by urination. It is a hollow muscular, and elastic organ, and sits on the pelvic floor. Urine enters the bladder via the ureters and exits via the urethra