3. Discuss the evolutionary relationships among the four classes of sponges.

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.

Plz ! having a smooth seeds is the dominant trait. having wrinkled seeds is a recessive trait. the offspring of two plants with smooth seeds, a. must have smooth seeds. b. may have smooth or wrinkled seeds. c. must have wrinkled seeds. d. have a 25% change of having smooth seeds.

The specific heat of ice is 0.5 calories/gram°c. 20 grams of ice will require ll calories to raise the temperature 1°c. 05