Its "C"Oxygen because it is used as oxidative phosphorylation
Two factors contributed to the success of the pteridophytes: the extreme miniaturization of the gametophytic generation and an important development of the sporophytic generation (development of the tree forms).
Pteridophytes are a group of plants that peaked in the Carboniferous (-300 million years). It is the first great terrestrial plant civilization. These plants would have appeared in the Devonian -400 million years ago, perhaps from certain primitive terrestrial plants which, unlike bryophytes, would have favored the diploid generation on the haploid generation.
Particularly well adapted to terrestrial life, they have created, thanks to the development of tree forms, immense forests whose fossilization is at the origin of coal deposits.
Pteridophytes are at the origin of an evolutionary lineage based on the extreme miniaturization of gametophytic generation and an important development of sporophytic generation, leading to all tracheophytes including current flowering plants. Pteridophytes are well adapted to terrestrial life, however fertilization still requires the presence of water since male gametes are swimmers.
Answer:
Binding of <u>ACh (acetylcholine) </u> to receptors (ligand-gated) on the sarcolemma at the neuromuscular junction is vital for depolarization of the muscle fiber.
Explanation:
It allows acetylcholine to be released into this synapse when an action potential hits a neuromuscular junction. Acetylcholine attaches to the nicotinic receptors localized on the post-synaptic membrane of the muscle fibre's motor end plate, a specialized region.
Hence , the answer is <u>ACh (acetylcholine) .</u>
I think it’s all of the above because they can all be found in the air and in water sources
