(a(i))[1]
State the name given to structure N in Fig. 2.1.
(a(ii))[1]
Cell M in Fig. 2.1 secretes mucus. State the name given to cell M.
(a(iii))[1]
State one other place in the body where mucus-secreting cells are present.
(a(iv))[4]
Describe and explain how a villus is structurally adapted to carry out its function.
(b)[1]
State the name of the main blood vessel that carries blood from the small intestine to the liver.
(c)[2]
Describe the meaning of the term stem cell.
(d)[5]
Explain why the average number of mitochondria differs in each type of cell.