HELPP PLZZ!! What are the main functions of the human skeletal system?
Question 21 options:

To support the body, protect the organs, produce blood cells, and store calcium

To regulate the composition of body fluids by removing metabolic wastes and retaining a balance of water, salt, and other nutrients

To regulate and maintain bodily functions by producing hormones and releasing them into the bloodstream

To enable the diffusion of oxygen into the bloodstream and the removal of carbon dioxide from the bloodstream

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.