An open circulatory system differs from a closed one in that:

A. The open circulatory system has a combination of blood vessels and large thin-walled sinuses whereas a closed circulatory system has only vessels.
B. A closed circulatory system is completely encased in the body cavity whereas the open one is not.
C. An open circulatory system opens into the heart whereas the closed circulatory system does not.
D. An open circulatory system opens into arteries and is drained by veins whereas in a closed one it is just the reverse.
E. An open circulatory system drains into the mantle cavity whereas a closed circulatory system drains into the hemolymph.


A. The open circulatory system has a combination of blood vessels and large thin-walled sinuses whereas a closed circulatory system has only vessels.

Biology & Microbiology

You might also like to view...

Most of the eukaryotic genomes described in the text have more than ________

A) 50 chromosomes B) 50,000 genes C) ten million genes D) 100,000 genes E) a million base pairs

Biology & Microbiology

When referring to cell division, oncogenes are most like ________ while tumor suppressor genes are most like ________

A) the brakes on a car… the gas pedal on a car B) the gas pedal on a car… the brakes on a car C) the steering wheel on a car… the gas pedal on a car D) the brakes on a car… the steering wheel on a car

Biology & Microbiology

The smallest functional unit of life is known as a(n) ________

Fill in the blank(s) with correct word

Biology & Microbiology

How does HOTAIR exert its function?

A. guide B. ribozyme C. scaffold D. blocker E. template F. decoy G. primer

Biology & Microbiology