A drought occurs in an environment with a large plant population. Which element of natural selection is most likely to enable part of the population to survive and reproduce?
a. the potential for the plant population to produce more offspring than can survive
b. a change in climate conditions
c. competition with other plant and animal populations for finite water resources
d. some individual plants inherited traits that enable them to survive a drought

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.

Several billion years ago which gas was the least prevailant in the atmosphere

If an organ has six haploid chromosomes,how many chromosomes are present. 6 12