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
Answer: D. None of the above
Explanation:
Heredity can be defined as a biological process that involves the passing on of characters or traits from parents to their offsprings genetically. These traits can be physical for example, height, colour of eyes or mental for example, intelligence.