What does an organism’s phenotype describe

Phenotype refers to observable traits of an organism physically.

Explanation:

The phenotype is the characteristics or physical expression, of that trait. When 2 individuals that have even the variation in their genes are said to have different genotypes but it not necessary that it will change the phenotype as well.

Thus, the set of observable traits of an organism resulting from the reaction of its genotype with the outside environment is considered as the phenotype of the individual trait.

the core of the sun is so hot and there is so much pressure, nuclear fusion takes place, hydrogen is changed to helium. nuclear fusion creates heat and photons. when the heat reaches the earth it warms the molecules of the atmosphere, and they warm other molecules and so on.