1.A cloud contracts under gravity 2.a disk forms because angular momentum is conserved 3.Nuclear reaction begin and a star is born 4.Clumps form from the central star 5. Planitesimals form from collision
<span><span>Clouds of gas form within galaxies. </span><span>Formation of structure within the gas clouds, due to "turbulence" and activity of new stars. </span><span>Random turbulent processes lead to regions dense enough to collapse under their own weight, in spite of a hostile environment. </span><span>As blob collapses, a disk forms, with growing "protostar" at the center. </span><span>At the same time, bipolar outflows from forming star/disk system begin. </span><span>Material is processed, moving in from the blob to the disk. What is not lost in the outflow builds up on the protostar. </span><span>When the protostar begins to undergo fusion, it becomes a real star. </span><span>Once the outflow ceases and the "accretion" phase that lead to the buildup of the star ends, a disk of "leftover" material is left around the star. </span><span>At or near the end of the star-formation process, the remaining material in the "circumstellar disk" (a.k.a. "protoplanetary disk") forms a variety of planets. </span><span>Eventually, all that is left behind is a new star, perhaps some planets, and a disk of left-over ground-up solids, visible as a "Debris Disk"around stars other than the Sun, and known as the "Zodaical Dust Disk" around the Sun.</span></span>
c.The products of photosynthesis are the reactants of respiration.
Explanation:
Photosynthesis and Respiration can be thought of as opposites. Photosynthesis is taking in CO2 and energy and releasing O2, while Respiration is taking in O2 and energy to release CO2.