Cyclostomata are fish made of cartilage without a jaw made of bone

The correct answer for the blank is-

without a jaw.

Cyclostomata is a group of jaw-less fishes ( belonging to the super-class agnatha) under the phylum chordata.

It possesses the lampreys and hag-fishes, which are living jawless fishes.  Both these groups possess mouths without jaws. Their epidermal structures are sharp, which act as as teeth, and branchial arches are located internally (unlike jawed fishes, which have externally positioned branchial arches).

Thus, without a jaw is the right answer.

answer; i believe that the correct answer is (light);

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.