Which piece of evidence supporting the theory of plate tectonics was discovered most recently?
a. the alignment of magnetic minerals in oceanic crust
b. the similarities in the coastlines of south america and africa
c. the fossil trilobites found in north america and the british isles
d. the occurrence of volcanic and earthquake activity near continental boundaries

There are few cells in the body that do not undergo mitosis: most somatic cells divide regularly, some more than others. take for example the cells that line the digestive tract. these cells must be frequently replaced because they are constantly eroded by the movement of food through the tract. what mechanism(s) is/are in place to ensure that these cells are exact copies of the mother cell