Answer to Question 1
Pluto is predominantly composed of ice and rock, unlike the terrestrial planets which have little ice and the jovian planets which have (proportionally) little rock. Further, its orbit has a much higher eccentricity and inclination than the terrestrial and jovian planets which orbit close to the ecliptic plane. Finally, there are many objects known, most smaller but at least one larger, than Pluto with similar compositions and similar orbits whereas the other planets have no other comparable companions in similar orbits.
Answer to Question 2
Low-mass stars swell up as red giants, stabilize with the helium flash, then again evolve into supergiants, shedding planetary nebula and leaving the white dwarf core exposed. By contrast, massive stars may form supergiants and continue fusing heavier and heavier elements up to iron, then end in much more violent deaths as Type II supernovae.
The Sun is the star at the center of the Solar System.
How to describe transformations of a sinusoidal function (y=a*sinb(x−c)+d)
Solar output
One of the best ways to reduce your chances of catching a cold
Solar system
Two ways of treating blocked coronary arteries, the main cause of heart attacks in older adults.