Answer: A . Has its collagen fibers randomly orientated.
Explanation:
In the microscopic anatomy of the bone, an osteon (basic microscope unit of the bone) can be arranged into two categories; woven bone or lamellar bone.
As the name suggests woven bone is characterized by the random orientation of the collagen fibers . These collagen fibers haphazardly form to give the visual appearance of an intertwined (woven) network of collagen fibers.
Due to the randomness of the collagen fibers orientation woven bone is thus mechanically weaker than lamellar bone. Woven bone is formed/produced when osteoblasts produce osteoids rapidly within the bone matrix thus woven bone has the ability to form quickly as needed.
Woven bone is thus immature bone or pathologic bone with no stress orientation, it has a high percentage of osteocytes per unit volume and a high rate of turnover.
Answer/Explanation:
EGFR stands for epidermal growth factor receptor. It is a transmembrane protein acting as a tyrosine kinase receptor for epidermal growth factor ligands, which are associated with promoting cell division and proliferation. When epidermal growth factor binds to the receptor, it becomes activated and undergoes dimerization and autophosphorylation.
A mutation could occur making the receptor overactive. That is, it does not require ligand binding to become activated, meaning it is always in an "on" state. This would lead to uncontrolled proliferation, a hallmark of cancer.
B. The oldest crust is closest to the mid-ocean ridge.
Answer:
A cell carries out all the processes of the body which includes producing energy and storing it, making proteins which are molecules which have roles in metabolism, transportation of other molecules and DNA replication.
