Question

Human beings are
A) Plantigrade
B) Digitigrades
C) Unguligrade
D) None of the above

Answer 1

Hint: Due to the difference in the body structure and posture different animals adapt to different locomotion systems. This difference also used to categories the mammals according to their locomotion technique and their speed.

Complete Answer:
- There are many locomotor systems that are adapted by the terrestrial mammals. These systems include the plantigrade locomotion, the digitigrades locomotion, and the unguligrade locomotion.
- The plantigrade locomotion means walk with the toes and metatarsals flat on the ground, the digitigrades locomotion means walking on the toes with wrist and heels permanently up, and the ungulates locomotion means walking on the nails or the hoof with wrist and heels raised permanently.
- The plantigrade mammals have legs that involve the bones of humerus and the bones of radius and ulna. The digitigrades mammals involve the metatarsals, and the unguligrade mammals have legs that include the phalanges.
- The humans are plantigrade mammals as they walk wholly on the foot so that the weight and the stability of the body are in balance. The feet of the plantigrade animals have larger surface area as we humans have.
- The plantigrade foot in humans is for maintaining the sitting and the static posture. The advantage of having a plantigrade foot is, it improves the fighting performance as it gets easier to kick with this kind of foot but along with the advantages there is an disadvantage also, that is, the speed of the plantigrade mammals is lower than the others.

Thus, the correct option is ‘A’. Plantigrade.

Note: The digitigrade mammals include the pigs, hippos, mesonychids, cats, hyenas, elephant, capybaras, pakicetus, thylacine, etc. The unguligrade mammals include the horses, tapirs, zebra, rhinoceroses, camels, deer, sheep, cattles, etc.