Question

Choose the correct statements regarding frog's anatomy.
A. Hepatic portal system is the special venous connection between liver and intestine.
B. There are twelve pairs of cranial nerves arising from the brain.
C. The ureters and oviducts open separately into the cloaca in female frogs.
D. Hind-brain consists of cerebellum, medulla oblongata and optic lobes.
E. Sinus venosus joins the right atrium of heart.
Choose the correct answer from the options given below:

• A. B and D only
• B. A, B and C only
• C. A, C and E only
• D. B and C only

Hint:

Logic Tip: A quick way to eliminate options is remembering that amphibians only have 10 pairs of cranial nerves. Knowing Statement B is false immediately eliminates options 1, 2, and 4, leaving option 3 as the only possible correct answer!

Answer 1

The Correct Option is C

Concept:
The anatomy of a frog (typically Rana tigrina) has specific features in its circulatory, nervous, and reproductive systems that differ from higher vertebrates like mammals. Evaluating each structural claim is necessary to filter the correct statements.
Step 1:
The hepatic portal system is indeed a specialized venous connection between the liver and the intestine in frogs. This allows nutrient-rich blood from the gut to be processed by the liver before entering the general circulation. Thus, Statement A is correct.
Step 2:
Frogs are amphibians and possess only 10 pairs of cranial nerves arising from the brain, unlike amniotes (reptiles, birds, and mammals) which possess 12 pairs. Thus, Statement B is incorrect.
Step 3:
In female frogs, the excretory and reproductive tracts are distinct. The ureters (carrying urine) and the oviducts (carrying eggs) open separately into the cloaca. (In male frogs, the ureter acts as a urinogenital duct). Thus, Statement C is correct.
Step 4:
The frog's brain is divided into forebrain, midbrain, and hindbrain. The optic lobes are a pair of prominent structures located in the mid-brain, not the hind-brain. The hind-brain consists only of the cerebellum and the medulla oblongata. Thus, Statement D is incorrect.
Step 5:
The frog's heart is three-chambered (two atria, one ventricle). The sinus venosus is an additional triangular chamber on the dorsal side of the heart that receives deoxygenated blood from the major veins (venae cavae) and opens into the right atrium. Thus, Statement E is correct.
Step 6:
Since statements A, C, and E are correct, the matching combination is option (3).