What is the relationship between Earth’s mass and its atmosphere?

Mass is proportional to gravity and gravity is necessary to hold an atmosphere, therefore mass would seem to be very important for the ability for a body to have an atmosphere. However there are quite a few examples that show that it doesn't require that much mass to get an atmosphere.

Explanation:

Answer + Explanation : Mass is proportional to gravity and gravity is necessary to hold an atmosphere, therefore mass would seem to be very important for the ability for a body to have an atmosphere.

at positions a, g kinetic energy is maximum.

at position d, potential energy is maximum.

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).