Spongy bone has trabecular which serve as reinforcing plates against a force. The loss of spongy bones causes weakening of the internal support that the compact bone requires and the entire bone breaks.
Unlike the hippo's ancestor, whale ancestors moved to the sea and evolved into swimming creatures over a period of about 8 million years. Fossils of gigantic ancient whales called Basilosaurus were first mistaken for dinasaur fossils but were later recognised as mammals.
Another element that is important to bones is calcium
The correct answer is cell wall
Answer:
The calcium concentration must be greater OUTSIDE
the cell than INSIDE the cell.
Explanation:
Calcium has a vital role in the body, it is necessary for:
- exocytosis
- muscle contraction
- normal excitability of neurons
- blood coagulation
- building and maintaining bones and teeth
- enzymatic activity