Leukemia is a cancer of white blood cells, or leukocytes. when chemotherapy alone is not successful, physicians
sometimes turn to bone marrow transplants.
a bone marrow transplant includes several steps. order these steps for a successful transplant to cure leukemia.

a. donor match located
b. a sample of donor bone marrow containing healthy stem cells is introduced into the patient's bloodstream
c. patient's existing bone marrow and abnormal leukocytes are killed using a combination of chemotherapy and
radiation
d. donor stem cells will migrate to patient's bone marrow and begin producing healthy leukocytes

Read the following scenario to answer the following question. in some zoos, rare crosses between a male lion and a female tiger have produced hybrid offspring called "ligers." male ligers are sterile but some female ligers are fertile. in the wild, lion and tiger ranges do not naturally overlap, making such a cross unlikely. furthermore, the solitary behavior of tigers and the social organizations of lions create behavioral differences. applying the biological species concept, the sterility of ligers reveals that a. lions are probably a subspecies of tigers b. tigers and lions are the same species c. a new species called "ligers" is forming d. tigers and lions are separate species

Which element forms the basis of all organic organisms a carbon b oxygen c hydrogen d nitrogen

Genetic disorders can result when sister chromatids fail to seperate properly. during what phase is this problem most likely to occur?