In Figure 33

question 79

Multiple Choice

In Figure 33.2, which two main clades branch from the most recent common ancestor of the eumetazoans?

• A) Porifera and Cnidaria
• B) Lophotrochozoa and Ecdysozoa
• C) Cnidaria and Bilateria
• D) Deuterostomia and Bilateria

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Definitions:

Venule

Minute vein, consisting of endothelium and a few scattered smooth muscles, that carries blood away from capillaries.

Systemic Blood Vessels

The network of blood vessels that circulate blood to and from the heart and all body parts, excluding the lungs.

Left Ventricle

The chamber of the heart that pumps oxygenated blood out through the aorta to the rest of the body.

Right Atrium

The right upper chamber of the heart that receives deoxygenated blood from the body via the venae cavae.