What is one reason why plants have accessory pigment molecules, like chlorophyll b and carotenoids?
a) to reflect more energy
b) to absorb energy in parts of the electromagnetic spectrum that chlorophyll a cannot
c) to give them different colors
d) because plants cannot make enough chlorophyll a for all of their energy needs

The correct answer is: B) to absorb energy in parts of the electromagnetic spectrum that chlorophyll a cannot

Accessory pigments have different electromagnetic spectrum  than the main pigment (because of their structural differences), so they absorb light and transfer that energy to photosystem chlorophyll. Also, some of the accessory pigments such as carotenoids can work as antioxidants or can absorb and dissipate excess light energy.  

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.