Lancelets circulatory system is best described as?

Explore the Diversity of Life Test. Challenge your understanding with multiple-choice questions and learn with instant feedback. Prep for the exam and gain insights on living organisms!

Multiple Choice

Lancelets circulatory system is best described as?

Explanation:
Lancelets have a closed circulatory system, meaning blood stays inside vessels rather than bathing tissues directly. They lack a true heart; instead, contractile blood vessels generate the pumping action that moves blood through the dorsal and ventral vessels and into the capillary beds of the pharyngeal slits. This combination—blood confined to vessels with vessel-wall contractions but no central pumping chamber—best fits a closed system without a heart. A diffusion-only description would ignore the presence of vessels, and a closed system with a prominent heart would imply a true cardiac chamber, which lancelets do not have.

Lancelets have a closed circulatory system, meaning blood stays inside vessels rather than bathing tissues directly. They lack a true heart; instead, contractile blood vessels generate the pumping action that moves blood through the dorsal and ventral vessels and into the capillary beds of the pharyngeal slits. This combination—blood confined to vessels with vessel-wall contractions but no central pumping chamber—best fits a closed system without a heart. A diffusion-only description would ignore the presence of vessels, and a closed system with a prominent heart would imply a true cardiac chamber, which lancelets do not have.

More Multiple Choice Questions
Subscribe

Get the latest from Passetra

You can unsubscribe at any time. Read our privacy policy