It is a scientific name whereby each species receives Latin or Latinized name of two parts. The first indicating genus and the second being a specific name.
There is only two possible offspring.
Bb and bb
Homo is the same
Hetero is different
b b
B <u> Bb </u> <u> Bb</u>
b <u> bb </u> <u> bb </u>
The mass is increased as two things are added together so the two masses of the two substances are added together.