1. Hemoptopoietic stem cell can give rise to
a) eythorocytes
b) erythocytes and lymphocytes
c) all blood cells and macrophages
d) all blood cells,macrophages,and skin cells
e) all blood cells,macrophages,skin cells

2. When stem cells of the intestinal epithelium and epidermisdivide, they give rise to two different cells: one stem cell andone _________ cell
a) goblet
b) crypt
c) g0
d) transit-amplifying
e) eteroendocrine

3. Mammalian embyonic stem cells are cultured from cells taken from
a) the 4-cell embyo
b) the inner cell mass
c) trophoblast cells
d) amnion cells
e) chorion cells

4. tumor initiation occurs in a
a) single protein molecule
b) single cell
c) few cells
d) single tissue
e) single organ

5.Nonhereditary retinoblastoma develops only when
a) a somatic mutation inactivates the Rb gene
b) a somatic mutation activates the Rb gene
c) two somatic mutations inactivate two serparate Rbgenes
d) one germ-line mutation and one somatic mutation inactivateRb genes
e) two germ-line mutations inactivate two sep Rb genes