NEETZoologyLocomotion and Movement
Which of the following is a characteristic feature of the skeletal system that is conserved across almost all mammals, including human beings?
Options
- APresence of exactly twelve thoracic vertebrae
- BAtlas articulating with a single occipital condyle
- CTotal of thirty-three bones in the adult vertebral column
- DPresence of seven cervical vertebrae
Correct answer
D. Presence of seven cervical vertebrae
Step-by-step solution
According to NCERT, a highly conserved characteristic of the mammalian axial skeleton is that the number of cervical vertebrae is seven in almost all mammals, including human beings. The other options are incorrect because: - The number of thoracic vertebrae varies significantly among different mammals (e.g., humans have 12, but horses have 18). - Mammals possess a dicondylic skull, meaning the atlas articulates with two occipital condyles, not one. - The total number of bones in the adult vertebral column varies a