During which period did the presence of stromatolites decline?

Which of the following is the main purpose of a human community?

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.

Put the following processes of protein synthesis in the correct order: - dna strands unwind and separate - mrna copies dna according to complimentary base pairing - trna's anticodons bring amino acids to the corresponding mrna codons - amino acids bind to each other making a protein - mrna leaves the nucleus - a stop codon is reached, the newly formed protein is released to go do its job for the cell