Survival of at least a few members of a population after a major environmental change is most dependent on
1) the population having an individual that is adapted to the original environment 2) the population having an individual that is adapted to great changes in the temperature and its environment
3) variations in many different traits in many individuals in the population
4) no variations in the color of the fur, skin, or feathers of the individuals in the population

Dwarf galaxies are select one: a. relatively rare. b. not very bright c. mostly spiral shaped. d. none of these.

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

Which blood cell spend most of their time in the lymphatic system?