What is the longest and strongest bone in the human body

it would be the femur

explanation: the femur, is the longest, heaviest, and strongest bone in the entire human body. all of the body's weight is supported by the femurs during many activities, such as running, jumping, walking, and standing. extreme forces also act upon the femur thanks to the strength of the muscles of the hip and thigh. the head of the femur inserts into the acetabulum.
distally, the femur forms the knee joint by articulating with the tibia at the medial and lateral condyles.

Ithink the dna sequences may vary but the amino acid sequences are identical. 

D.) domain, kingdom, phylum, class, order, family, genus, species