Based on these images, what can you say about the tentacles of an octopus and the limbs of a lizard?
a)they’re homologous structures.
b)they’re analogous structures.
c)they’re vestigial structures.
d)they’re neither homologous nor analogous structures.
e)they’re neither vestigial nor homologous structures.

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.

the answer is b.) hydrogen bonds between bases.