In broad terms, finches. In specific terms, he observed how over time, the beak sizes and shapes of said finches changed to adapt to the food sources available.
I hope I was able to help. Best of luck.
<span>Birds and dinosaurs show homology because they are closely related, such as pigeon and tendon. They have different types of wings, but birds have evolved from dinosaurs. Unlike other species such as insects, which can be a homoplasy or a homology. This is due to its world and complexity.</span>
Plants use and produce both oxygen and carbon dioxide.
Answer:
The Mitral/Bicuspid Valve
Explanation:
The heart is composed of 4 chambers: left and right atria, and left and right ventricles. The “right heart” (right atrium and ventricle) receives deoxygenated blood from the systemic circulation through the Vena Cava, and impels this blood towards the lungs through the Pulmonary Arteries where it will be oxygenated. The “left heart” (left atrium and left ventricle) receives oxygenated blood from the pulmonary circulation through the Pulmonary veins and impels this blood towards the systemic circulation through the Aorta artery.
The systemic and pulmonary circuits work in series, and maintaining the unidirectional course of the blood flow is very important. This can be done by the presence of fibrous valves that are present between the atrium and the ventricles, and in between the ventricles and the Pulmonary/Aorta artery.
The location of these structures are as follows:
Systemic circulation ⇒ Right Atrium → [Tricuspid Valve] → Right Ventricle → [Pulmonary Valve] → Pulmonary Artery ⇒ Pulmonary circulation
Pulmonary circulation ⇒ Left Atrium → [Mitral/Bicuspid Valve] → Left Ventricle → [Aortic Valve] → Aorta ⇒ Systemic circulation