<span>Bone marrow which is located <span>within the spongy or cancellous portions of bones is the essential site of new blood cell production or hematopoiesis. Bone marrow contains stem cells which able to differentiate into specialized cell types. People with diseases like blood cancers, such as leukaemia and lymphoma, sickle cell anaemia, and other rely on bone marrow transplantation to survive.</span></span>
Wind........................
Answer:
A) they help transport some substances through the membrane.
Explanation:
The membrane proteins that span the bilayer of phospholipids help in the transport of polar, large and charged substances across the membrane. The nonpolar core of the membrane does not allow these charged and polar substances to pass through. Proteins serving as channels form pores to allow movement of the specific substances.
On the other hand, carrier transport proteins of the membrane bind to the substances present at one side of the membrane and deliver them to the opposite side.
Skin is the Largest barrier agaisnt Pathogens which include Bacteria which cause infections.
