The right option is; Hooke
Robert Hooke was an English scientist that first recognized the cell as the universal unit of life. In 1665, Robert Hooke observed honeycomb-like structure when he viewed very tiny slices of cork using a coarse compound microscope. He called the structures cells but he did not know their actual structure and function.
Answer:
(a) Allow movement in only one plane/direction (that is extension or flexion)
(b) The skeletal system also produces blood cells in their bone marrow
Regolith can be brought back to earth.
