CRQ QUESTION: Variation in a trait is a required condition for natural selection to act on a population for that trait. Assuming a population of organisms started with only one form of a trait, what are two ways variation in the trait could be introduced into the population? Explain your answer.

Why are scientists concerned about the depletion of the ozone levels in the stratosphere?

Which statement best describes a typical difference that could be found between the “analysis” and “conclusion” sections of a lab report?

Subduction zones form when an oceanic plate collides with another oceanic plate or continental plate. the continental crust is lighter and less dense than oceanic crust. continental crust's density is approximately 2.7 grams per cubic centimeter. oceanic crust is thinner and the average density is about 3.3 cubic centimeters. when the two crustal plates converge the oceanic plate always bends and subducts beneath a continental plate. once the oceanic crust subjects, the rocks are subjected to changes in heat and pressure. because of this, we would expect to find rocks in the area of a subduction. a) clastic b) igneous c) metamorphic d) sedimentary