Why are sedimentary rocks the only ones to show fossils

Which of the following examples can cause gene flow between populations? a.an increase in predators to a population of zebra b.a volcanic eruption that kills half of a population of mice c.bird droppings that contain seeds from a different location d.a person that sprays a toxin on a group of mosquitoes

What happens when the cell copies its chromosomes

Name the organs of humanelemintary canal.