Context and question: No single feature distinguishes Annelids from other invertebrate phyla, but they have a distinctive combination of features. Their bodies are long, with segments that are divided externally by shallow ring-like constrictions called annuli and internally by septa ("partitions") at the same points, although in some species the septa are incomplete and in a few cases missing. Most of the segments contain the same sets of organs, although sharing a common gut, circulatory system and nervous system makes them inter-dependent. Their bodies are covered by a cuticle (outer covering) that does not contain cells but is secreted by cells in the skin underneath, is made of tough but flexible collagen and does not molt – on the other hand arthropods' cuticles are made of the more rigid α-chitin, and molt until the arthropods reach their full size. Most annelids have closed circulatory systems, where the blood makes its entire circuit via blood vessels.
What externally combines annelids' segments?
Answer: unanswerable
Context and question: Winter, and a deteriorating supply situation on both sides of troops and materiel, led to a halt in ground operations. Sevastopol remained invested by the allies, while the allied armies were hemmed in by the Russian army in the interior. On 14 November a storm sank thirty allied transport ships including HMS Prince which was carrying a cargo of winter clothing.:435 The storm and heavy traffic caused the road from the coast to the troops to disintegrate into a quagmire, requiring engineers to devote most of their time to its repair including quarrying stone. A tramroad was ordered. It arrived in January with a civilian engineering crew, however it was March before it was sufficiently advanced to be of any appreciable value.:439 An Electrical telegraph was also ordered, but the frozen ground delayed its installation until March, when communications from the base port of Balaklava to the British HQ was established. The Pipe-and-cable-laying plough failed because of the hard frozen soil, but even so 21 miles of cable were laid.:449
What arrived in January with an engineering crew?
Answer: A tramroad
Context and question: The annelids are bilaterally symmetrical, triploblastic, coelomate, invertebrate organisms. They also have parapodia for locomotion. Most textbooks still use the traditional division into polychaetes (almost all marine), oligochaetes (which include earthworms) and leech-like species. Cladistic research since 1997 has radically changed this scheme, viewing leeches as a sub-group of oligochaetes and oligochaetes as a sub-group of polychaetes. In addition, the Pogonophora, Echiura and Sipuncula, previously regarded as separate phyla, are now regarded as sub-groups of polychaetes. Annelids are considered members of the Lophotrochozoa, a "super-phylum" of protostomes that also includes molluscs, brachiopods, flatworms and nemerteans.
What do annelids use to move?
Answer:
parapodia