12. Arthropods are considered to be segmented - their basic body plan, at least as embryos, consists of repeating units. Some of this feature remains visible on the outside. What parts of the crayfish body show signs of segmentation?

The walking legs, cheliped, thorax and abdomen

Explanation:

Crayfish belong to class of crustaceans of the phylum arthropoda. They are classified by having segmented body and jointed appendages.

Crayfish is divided into two body segments, the cephalothorax and abdomen. The cephalothorax contain the maxillipede for holding food during eating, cheliped is a large claws for defence, the walking legs is use for movement.

d

explanation:

the higher the instrument the better

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.