Digestive Tract: Trace the flow across the digestive tract Mouth --> __1__ --> __2__ --> __3__ --> __4__ --> __5__ --> __6__ --> __7__ --> __8__ --> __9__ --> __10__ --> __11__ --> __12__ --> __13__ --> __14__ --> anus

Fossils found in strata reveal that a) innate drive to complexity of life b) unused body parts decrease in size c) older strata carry fossils that differ greatly from living organisms d) geologic changes occur quickly on earth

Which of the following is an oxidation-reduction reaction? (pictured below)

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.