Which of the following best explain why earthquakes occur? O The movement of people, animals, automobiles, and trains causes earthquakes.
O The movement of the tectonic plates can cause energy to be stored in rocks. A
sudden release of this stored energy causes earthquakes.
O The force of the Earth orbiting the Sun causes earthquakes.
O All earthquakes are caused by giant asteroids crashing into Earth.

Where do homologous chromosomes exchange genetic material through crossing over?               a.  chlorophyll    b.  centrosomes    c.  centromeres    d.  chiasma

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.

The term used to describe a disease-causing microorganism isa. virus.b. infection.c. pathogen.d. microbe.e. bacterium.