Concept:The frog's circulatory, nervous, and excretory systems have specific anatomical features.
Key Fact:The hepatic portal system connects the liver to the intestine; the sinus venosus joins the right atrium; and female frogs have separate openings of ureters and oviducts into the cloaca.
Explanation:Statement A is correct because the hepatic portal system is a special venous network between the liver and intestine.
Statement B is incorrect because frogs have only ten pairs of cranial nerves, not twelve.
Statement C is correct because in female frogs, the ureters and oviducts open separately into the cloaca.
Statement D is incorrect because the hindbrain lacks optic lobes; the optic lobes are part of the midbrain.
Statement E is correct because the sinus venosus is a triangular chamber that joins the right atrium.
Answer:Thus, the correct statements are A, C, and E only. The correct option is D.
