Our solar system is thought to have started with the birth of our Sun, which formed from a cloud of interstellar dust and gas. T
his cloud condensed and eventually collapsed from its own gravitational pull. The heat and pressure built up, forming a protostar. Eventually nuclear fusion began. Planets formed from remaining dust and gas orbiting the protostar. This explanation best describes _____.
the nebular theory
the big bang theory
the inflation theory
the condensation theory
Metabolism in eukaryotic cells depends on the endoplasmic reticulum because it transports materials between membrane-bounded organelles within the cell.
