(a) Ureters in FrogIn frogs two ureters emerge from the kidneys. In male frog the ureters act as urinogenital duct which opens into the cloaca. It helps in passing the urine as well as the sperm to the exterior. In females the ureters and oviduct open seperately in the cloaca. The ureters excrete only the urine. (b) Malpighian tubulesThe malpighian tubules help in the removal of excretory products present in the haemolymph of the cockroach. (c) Body wall in the earthwormThe moist body wall helps in respiration. The circular and the longitudinal muscles present below the cuticle along with the setae, which is embedded in the epidermal pits, help in the locomotion of the earthworm.