Biology · Structural Organisation in Animals · NEET
The order is: Testes to Vasa efferentia to Kidney to Bidder's canal to Urinogenital duct to Cloaca. This is the sequence NCERT gives and the one NEET asks. Notice the sperm pass THROUGH the kidney before reaching Bidder's canal. Do not put the kidney at the end.
In frogs the male reproductive and urinary systems share ducts (a urinogenital system). The 10 to 12 vasa efferentia leave the testes and enter the kidney on their side, where they open into Bidder's canal inside the kidney. So the kidney is a real stop on the sperm route. This is why the duct that finally carries sperm is called the urino-genital duct (it carries both urine and sperm).
In a frog there are 10 to 12 vasa efferentia (fine tubes) that arise from the testes and enter the kidney. In humans there is one vas deferens per side that leaves the epididymis and does NOT pass through the kidney. NEET mixes these up on purpose, so remember: frog = many vasa efferentia + kidney route; human = single vas deferens, no kidney.
Bidder's canal is a longitudinal collecting canal inside the kidney of the male frog. The vasa efferentia open into it, and it then connects to the urinogenital duct. It is a favourite NEET keyword because students confuse it with the ureter.
Mesorchium is the double fold of peritoneum (a thin membrane) that holds the paired testes attached to the upper part of the kidneys. In females the matching fold for ovaries is the mesovarium. Do not confuse mesorchium (testes) with mesovarium (ovaries).
There is a pair of testes (two). They are yellowish and ovoid (oval) in shape. NCERT states this word-for-word, so 'yellowish ovoid' is the exact phrase to remember for one-mark statement questions.
The cloaca is a single small median chamber that opens to the outside. In the frog it passes out three things: faecal matter (from the rectum), urine, and sperms. Because one opening does all three jobs, the frog does not have separate anal, urinary and genital openings like mammals.
Select the correct route for the passage of sperms in male frogs:
Try the real previous-year questions from this chapter — each with the answer and a full solution.
No. NCERT does not describe a seminal vesicle in the frog's sperm pathway. Any NEET option that inserts a 'seminal vesicle' into the frog route is a distractor. The correct ducts are vasa efferentia, Bidder's canal and the urinogenital duct.
In the male frog the same duct carries both urine and sperm, so it is called the urinogenital duct. Calling it only a 'ureter' is incomplete, and a NEET option that ends the sperm path at the 'ureter' is wrong.
The male has a pair of yellowish ovoid testes attached by the mesorchium, with vasa efferentia, Bidder's canal and a urinogenital duct. The female has a pair of ovaries (no functional link with the kidney) whose oviducts open separately into the cloaca. Fertilisation is external in water.
The frog sperm pathway is a direct, high-yield one-liner that NEET has asked as a sequence question (2017). It rewards exact ordering, so memorising Testes to Vasa efferentia to Kidney to Bidder's canal to Urinogenital duct to Cloaca can secure a full mark with almost no reasoning.
