Which of the following groups of phase changes occur only when heat energy is removed or released from water. a. melting, evaporation, sublimation b. condensation, freezing, deposotion c. sublimation, deposition, melting d. melting, condensation, sublimation

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 are characteristics of flukes? check all that apply. a they are free living. b they are a type of flatworm. c they reproduce sexually. d they have eyespots. e they are segmented.

What are antigens and antibodies? how are they involved in the body’s response to incompatible blood?