Given enough time, the genetic and phenotypic divergence between populations will affect characters that influence reproduction: if individuals of the two populations were brought together, mating would be less likely, but if mating occurred, offspring would be nonviable or infertile. …
A blackbody is a convenient, ideal emitter that approximates the behavior of many materials when heated. It is “ideal” in the same sense that an ideal gas is a convenient, simple representation of real gases that works well, provided that the pressure …
A concave mirror, or converging mirror, has a reflecting surface that is recessed inward (away from the incident light). Concave mirrors reflect light inward to one focal point. They are used to focus light. Unlike convex mirrors, concave mirrors show …
The theory of natural selection stems from the observation that some individuals in a population are more likely to survive longer and have more offspring than others; thus, they will pass on more of their genes to the next generation. …
It is observing that electrons could be ejected from the clean surface of a metal when light having a frequency greater than some threshold frequency. Surprisingly, the kinetic energy of the ejected electrons did not depend on the brightness of …
Newton’s First Law states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. Newton’s second law states that the acceleration of an object is dependent upon two …
Mutations are changes to an organism’s DNA and are an important driver of diversity in populations. Species evolve because of mutations accumulating over time. The appearance of new mutations is the most common way to introduce novel genotypic and phenotypic …
The energies of electrons (energy levels) in an atom are quantized, described by quantum numbers: integer numbers having only specific allowed value and used to characterize the arrangement of electrons in an atom. An electron’s energy increases with increasing distance from …
The simplest way to see this is that all parts on the outside surface of the conductor will remain at the same potential, irrespective of the location of the charge inside the hollow part. Thus, if you think of solving …
Scientists use a tool called a phylogenetic tree to show the evolutionary pathways and connections among organisms. A phylogenetic tree is a diagram used to reflect evolutionary relationships among organisms or groups of organisms. Scientists consider phylogenetic trees to be …