The regulation of sodium:
a) involves hypothalamic osmoreceptor detection of ion concentration
b) involves aldosterone, a hormone that increases sodium excretion in the kidneys
c) is linked to blood pressure
d) is due to specific sodium receptors in the hypothalamus

spiders belong to a group of arachnids.

arachnids have the following traits :

they have two body parts.

they have eight legs unlike insects which have 6 legs.

they have no wings.

these traits distinguish them from insects.

the information that antonio is doubting us the statement that spiders differences are as a result of being first to evolve.

this is because the evolution of one species is independent of the other species.