Arthropods

yes

Not all arthropods have chewing mouthparts but for those that do:

Mandibles: For shearing, piercing, and processing food.

Labra (singular labrum): Functions as an "upper-lip."

Maxillae: Ancestral biramous (two part) appendages for manipulating and tasting food. Maxillae can be fused or modified into derived structures. In some insects the second maxillae are fused to form a lower lip (labrum).

no

No, myriapods are a subphylum of arthrpods, and include the centipedes, millipedes and their ilk. It would be better to say arthropoda includes all myriapods.

Gastropods are separate, in a different phylum - Mollusca (the molluscs), brachiopods likewise have their own phylum.

In taxonomy, 'class' has a specific denotation. Arthropoda (the arthropods) is a major division called a phylum. It falls under the animal kingdom (Animalia, or Metazoa) and also falls under other classifications such as Eukaryota, Opisthokonta, Eumetazoa, Bilateria, Protostomia, Ecdysozoa and Panarthropoda.

Below phylum are the subphyla and the classes, of which arthropoda has several, including the Malacostraca class (lobsters, shrimp, etc), the Insecta class (insects), and others.

lajkanz

The current system will classify organisms by Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species. Scientific names include the genus and species of the organism (like homo sapien for humans).

The exoskeleton

Yes, technically, being double jointed is real, but the correct name for it is hypermobility or hyperlaxity, which is what doctors and other medical people will refer to it as. Look those words up and you can discover a little more about being hypermobile. I am double jointed, and can do lots of weird things from my shoulders to my fingers, so it does make me angry to see somebody who says being double jointed isn't real. It is, but they may call it something else. It's all the same thing.

In taxonomy under phylum arthropoda are subphyla Chelicerata, Myriapoda, Crustacea, and Hexapoda. There is also an extinct class Marrellomorpha and an the extinct Trilobite subphylum. The chelicerata, like spiders, scorpions, mites, etc., get their name from having appendages appear before the mouth; myriapods like centipedes and millipedes characterized by a high count of body segments and legs; crustaceans like crabs, shrimp, woodlice characterized by their biramous (two-part) limbs and a nauplius larval form; hexapoda named for their consolidated thorax with only three pairs of legs.

Arthropods don't actually use red blood cells, nor hemoglobin; the arthropods that use oxygen-carrying molecules in their circulatory fluid (hemolymph) use hemocyanin, a copper-based protein rather than iron-based like hemoglobin. It's also not bound to cells but drifts around in the fluid. When oxygenated it turns a bluish color.

Note that the oxygenation strategy for most (but not all) arthropods is to get oxygen directly from the air, through openings in their segments (spiracles) that connect to a trachea and to smaller tubules connected directly to tissues, thus bypassing a liquid circulatory system.

Only some arthropods have a cephalothorax, like for example the lobster. Other arthropods have functionally separate (or non-fused) head and thorax, like many insects.

Members of class Chelicerata, order Arachnida and suborder Aranaea, being regular spiders. The cephalothorax bears the eyes, mouth, legs and musculature used to move these, and the abdomen contains the vital organs.

Arthropods do have a circulatory system to move oxygen and nutrients through their bodies, but it is an open design, meaning the organs and cells are bathed in circulatory fluid unlike our circulatory system which delivers blood to specific locations. Their internal body cavity is called a hemocoel, the fluid drains into open pores and is pumped by a simple dorsal heart. Their movements also help to move the fluid around. This liquid is called hemolymph and contains water, salts, proteins, carbohydrates and lipids, and an oxygen-carrying molecule.

A basitarsus is the basal segment of an arthropod tarsus - any of the arthropod's articulations in its foot.

Note that the term 'anthropod' should not be confused with 'arthropod' - anthropod is not a phylum nor taxon but is a general term meaning human or humanoid.

By count the most arthropod species fall under the Insecta class, with a million species described and millions estimated yet to be described. By count, insects are over half of all living animals and by some estimates may constitute up to ninety percent of all living animals on the earth. In biomass, krill take the top spot weighing in from up to half to three quarters of a billion tonnes, and thus having a huge significance in the food chain.

Yes, jointing is critical in arthropod morphology owing to the general rigidity of the exoskeleton, and the very reason for the name of the phylum (Arthropoda loosely means "joint appendages"). Jointing provides mobility through flexion and extension of walking limbs, swimmerets, and wings; as also for signalling, digging, grasping, sensing, eating and other capabilities.

Pretty much all bugs are arthropods, with the exception of an informal usage of the word "bug" to describe a pathogen causing an illness. All insects are arthropods; non-insect arthropods like myriapods (centipedes and millipedes for example) are called bugs and are still arthropods. Arachnids including spiders and scorpions, which might be called bugs, are also arthropods; land crabs which might be referred to as "bugs" are arthropods.

In biology there is a group of insects called the "true bugs", including the shield bugs; also arthropods.

"Anthropod" isn't a phylum, but refers rather to a bipedal human or humanoid. The similar-spelled "Arthropod" should not be confused with it.

Arthropoda is a phylum under the animal kingdom characterized by segmented bodies, an exoskeleton made from chitin, and joint appendages.

Well arthropods have no vertebrae so they are cold blooded (ectothermic).

no

centipid