The Importance of the Circulatory System/Blood Vessels

True or False: Unicellular organisms have an open circulatory system.

• True

• False

True or False: Some multicellular organisms have no circulatory system.

• True

• False

Hemolymph is associated with which type of circulatory system?

• open

• closed

True or False: Organisms with an open circulatory system do not have a heart-like structure.

• True

• False

What is the purpose of the ostium in an open circulatory system?

• to pump out hemolymph

• to draw hemolymph back into the heart

Type of circulatory system where organs are bathed in the circulatory fluid:

• open

• closed

Type of circulatory system in an earthworm:

• open

• closed

Type of circulatory system in crustaceans:

• open

• closed

True or False: In a closed circulatory system, blood moves from the heart to increasingly larger blood vessels.

• true

• false

Which could be the proper sequence of blood movement in a closed circulatory system? Select all that apply.

• Body, Heart, Lungs, Body

• Heart, Body, Heart Lungs

• Lungs, Body, Heart, Lungs

• Lungs, Heart, Body, Heart