Tumor cells are cells that divide relentlessly, forming solid tumors or flooding the blood with abnormal cells.
Other than contributing to potential increase in diversity of species in an ecosystem, exotic species have positive benefits like removing toxins from the soil, regulating erosion, and controlling undesirable species.
Answer:
Natural selection, the keystone of evolution, can switch direction in a matter of months, a novel experiment on lizards reveals.
Lava that hardens on the surface is called an extrusion. The rock layers below an extrusion are always older than the extrusion. ... There, the magma cools and hardens into a mass of igneous rock called an intrusion. An intrusion is always younger than the rock layers around and beneath it.
