Convection occurs in the troposphere but not in the stratosphere because
A) the troposphere is warmer than the stratosphere.
B) the troposphere is cooler than the stratosphere.
C) lower altitudes of the troposphere are warmer than higher altitudes, unlike in the stratosphere.
D) higher altitudes of the troposphere are warmer than lower altitudes, unlike in the stratosphere.
E) the troposphere contains fewer greenhouse gases than the stratosphere.
Question 2
When is/was gravitational contraction an important energy generation mechanism for the Sun?
A) It was important when the Sun was forming from a shrinking interstellar cloud of gas.
B) It is the primary energy generation mechanism in the Sun today.
C) It has played a role throughout the Sun's history, but it was most important right after nuclear fusion began in the Sun's core.
D) It is important during periods when the Sun is going from solar maximum to solar minimum.
A melanistic jaguar is a colour morph which occurs at about 6% frequency in populations.
Internal structures of main sequence stars, convection zones with arrowed cycles and radiative zones
Diesel combustion occurs when fuel is injected into the hot, highly compressed air in the cylinder.
The Upper Troposphere: Westerly Winds in the Upper Atmosphere
Biosynthesis of methionine and threonine from homoserine, as it occurs in plants and bacteria
Conversion of F+ to an Hfr state occurs by integration of the F factor