Which of the following is true of annelids? a) They have a gastrovascular cavity. b) They have an open circulatory system. c) They have a nerve net. d) They have pseudocoeloms. e) They perform gas exchange across their skin.

e) They perform gas exchange across their skin.

Explanation:

Annelids are organisms which are invertebrates and are worms. Examples

Include earthworm, rag worm and leeches.

They don’t have a gastrovascular cavity. They don’t have an open circulatory system, instead it operates on a closed circulatory system.They lack pseudocoeloms which is the space between the endoderm and mesoderm. They however exchange gases through their moist skin.

d. the weight of the book

the element that provides strength to the exoskeletons of clams and oysters is phosphorus. this is so because calcium carbonate is the main component in the shells.

explanation: