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.
A, B and C only
- B.
B and D only
- C.
B and C only
- D.
A, C and E only
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We need to check each statement one by one against the known anatomy of a frog.
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Statement A: The hepatic portal system is indeed the special venous connection that carries blood between the liver and intestine, so this statement is correct.
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Statement B: Frogs have only 10 pairs of cranial nerves, not twelve (twelve pairs is a mammalian feature), so this statement is incorrect.
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Statement C: In female frogs, the ureters (carrying excretory waste) and the oviducts (carrying eggs) are separate ducts that open independently into the cloaca, so this statement is correct.
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Statement D: The hind-brain actually consists of the cerebellum and medulla oblongata only; the optic lobes belong to the mid-brain, so this statement is incorrect.
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Statement E: The sinus venosus is a thin-walled triangular sac that collects deoxygenated blood and opens into the right atrium of the heart, so this statement is correct.
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Since A, C, and E are the correct statements, they match option D.
Hence, the answer is D (A, C and E only).