An individual colony visible on an agar plate is composed of:. i. a single bacterial cell.
ii. a pile of millions of bacterial cells all descended from a single cell.
iii. the result of repeated cell division, generally starting with multiple cells.
iv. a pile of approximately 10,000 bacterial cells.

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.

Describe the response the kidneys have to dehydration and excessive water intake. what happens to the concentration of urine in each case ?

Onsider the paragraph above. what is one chemical property of water? a) water is a polar molecule. b) water is the universal solvent. c) water reacts with group 1 metals. d) water has a high specific heat capacity.