In birds,the sinus venosus persists as a patch of tissue in the right atrium and functions as
A)an atrioventricular valve.
B)the pulmonary trunk.
C)the bicuspid valve.
D)the pacemaker.
E)the entrance to the aorta.

Question

Quizplus · Accepted Answer

The sinus venosus in birds persists as a patch of tissue in the right atrium and functions as the pacemaker, controlling the heartbeat.

In Birds,the Sinus Venosus Persists as a Patch of Tissue