Question

In Earthworm, arrangement of blood vessels is

• A. Different in last fifteen segments
• B. Different in first thirteen segments
• C. Same throughout
• D. Different in middle thirteen segments

Answer 1

Answer: (B)

Different in first thirteen segments

The circulatory system of an earthworm is a closed type, as the blood flows only through the blood vessels. The blood vascular system of Pheretima posthuma consists of an elaborate system of blood vessels through which blood flows continuously.

The blood vessels and their arrangement in the first thirteen segments

The blood vessels of the circulatory system of earthworm include longitudinal blood vessels, hearts, anterior loops, and the ring vessels.

So the correct answer is 'Different in the first thirteen segments'.