The ultimate source of energy in the biosphere is

What is the rate of energy loss at different trophic levels in an energy pyramid (in $\%$)?

Assertion $A$: The amount of free energy in a system gradually decreases.
Reason $R$: During any transformation of energy,some amount of energy is lost in the form of heat.
Which option is correct for Assertion $A$ and Reason $R$?

The $10\; \%$ law is related to

Percentage of Photosynthetically Active Radiation $(PAR)$ that is captured by plants in the synthesis of organic matter is

Assertion: Ecosystems are not exempt from the second law of thermodynamics.
Reason: In a food chain,energy flow is bidirectional.