Mitosis is responsible for growth, repair, and maintenance in an organism because a) it occurs at a faster rate than meiosis. b) the chromosome number is reduced by half. c) exact duplicates of each mother cell are produced. d) it is the only process that involves replication of genetic material. eli

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.

Atypical human cell is approximately 12.00 μm in diameter and enclosed by a membrane that is 5.000 nm thick. (a) what is the volume of the cell including the membrane? (b) what is the volume of the cell membrane? (c) what percent of the total volume does its membrane occupy? to simplify the calculations, model the cell as a sphere. enter your answers using four significant figures.

What are the most explosive events that occur on the sun? umbras solar flares solar winds prominences