Which statement best explains why invertebrates often have outer skeletons but vertebrates do not? the outer skeleton provides protection, since invertebrates do not have backbones. the outer skeleton surrounds the spinal cord, since invertebrates do not have backbones. the outer skeleton invertebrates maintain homeostasis, since they lack spinal cords. the outer skeleton invertebrates maintain homeostasis, since they lack membrane-bound organelles.

Ans.

Invertebrates are lower eukaryotic organisms that lack a vertebral column or backbone. Vertebral column is present in vertebrates and provides protection and support to the body.

As invertebrates lack vertebral column, they show presence of an outer skeleton or exoskeleton. The exoskeleton performs same function as vertebral column, means it provides protection to the invertebrates.

Thus, the correct answer is option). 'the outer skeleton provides protection, since invertebrates do not have backbones.'

it enhances antibody production by t cells of the adaptive immune system.

hope i'm right

explanation: