Annelida
The phylum Annelida is made up of segemented worms such as earthworms and leeches. The segments on these worms each contain the elements of the body systems such as the excretory, circulatory, and endocrine system. All annelids, except leeches, also have chitonous hair-like structures, called setae, projecting from their cuticle.
Annelids have evovled into having well developed organs. They include a closed circulatory system and a digestive system with both anus and mouth. Their skin allows for the exchange of gases. Their nervous system consists of ganglia which is connected to nerve cords that are found down the length of the body. Annelids have a combination of organs, chemoreceptors, balance receptors, and photoreceptors; some also have very well developed eyes. Annelids are also able to produce both sexually and asexually for they have both female and male organs.
Annelids have evovled into having well developed organs. They include a closed circulatory system and a digestive system with both anus and mouth. Their skin allows for the exchange of gases. Their nervous system consists of ganglia which is connected to nerve cords that are found down the length of the body. Annelids have a combination of organs, chemoreceptors, balance receptors, and photoreceptors; some also have very well developed eyes. Annelids are also able to produce both sexually and asexually for they have both female and male organs.