Which of the following is an example of the skeletal system interacting directly with the
respiratory system?

a the ribcage expands to allow air to enter the lungs.
b the muscles attached to bones contract to lift your leg.
c the marrow inside bones produces white blood cells.
d the vertebrae protect the spinal cord from injury,

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.