Which labels best complete the flow chart? X: Producers undergo photosynthesis. Y: Decomposers return carbon to the soil and release waste. X: Decomposers return carbon to the soil and release waste. Y: Producers undergo photosynthesis. X: Decomposers take in carbon dioxide. Y: Producers absorb carbon through their roots. X: Producers absorb carbon through their roots. Y: Decomposers take in carbon dioxide.

option a is correct i.e.

explanation:

in context to the membrane of nerve impulse, the outer membrane of neuron is semi permeable that is only sodium ions can pass through the membrane i.e. smaller ions can pass through the membrane while larger ions cannot pass through it.

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.