Because the cuticle impedes the diffusion of gases through the body surface, arthropods possess special organs that permit gas exchange. In aquatic arthropods, these consist of feathery that have an extensive surface area in contact with the surrounding water. Terrestrial species have a highly developed system of .

a tetrad is the foursome during meiosis made by two homologous chromosomes that have each already replicated into a pair of sister chromatids.

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds

the food storage products of chrysophytes are oils or the polysaccharide laminarin.   formerly classified as plants, the chrysophytes contain the photosynthetic pigments chlorophyll a and c all but the yellow-green algae also contain the carotenoid pigment fucoxanthin.