Question

Cloaca of frog is common chamber for urinary tract, reproductive tract and
a. Alimentary canal
b. Portal system
c. Hepatic portal vein
d. Notochord lymphatic system

Answer 1

Hint: The cloaca is a small terminal sac-like structure which opens the anus, urogenital aperture and urinary bladder. It receives faecal, genital products and urine. Cloaca opens outside by the cloacal aperture located at the posterior end of the body.

Complete answer:
The Cloaca frog is a common chamber for the urinary tract, reproductive tract and alimentary canal. Duct arising from the kidney in male frog is both a urinary duct and a sperm duct, hence is called urinogenital duct. Each urinogenital duct runs posteriorly and opens into cloaca which is a common chamber for urine, sperms and faecal matter. All these products are passed out through cloacal aperture.

Frog is ureotelic, it excretes urea along with water. Blood is filtered by nephrons in kidneys. All the wastes are filtered out and useful substances are reabsorbed into blood. The remaining fluid forms urine which is carried out of the kidney by collecting vessels into the ureter and passes down to the cloaca. It is either stored (temporarily) in the urinary bladder or eliminated through cloacal aperture.

The ileum of frog leads into a broad, thin walled and wide tube known as rectum or large intestine and it is opened outside by the cloaca. The cloaca is the common chamber used for reproduction and excretion.

Hence, the correct answer is option (A).

Note: It is noted that the reproductive, alimentary and urinary products are not directly open into cloaca. Reproductive and urinary products transfer to cloaca by the duct called urinogenital duct and alimentary products transfer to cloaca by rectum.