It tells you what the paragraph is going to be about.
An F1 hybrid (or filial 1 hybrid) is the first filial generation of offspring of distinctly different parental types. F1 hybrids are used in genetics, and in selective breeding, where it may appear as F1 crossbreed. The term is sometimes written with a subscript, as F1 hybrid.
In our personal experience you get 60% of the resulting look/temperament of the puppies from 'mum'. An F1 cockapoo is the first cross of a cocker spaniel with a poodle, which one is mum and which one is dad will have a defining effect on the end result. F1 is considered to have the optimum hybrid vigor and have a hypo allergenic coat with three potential variations: tight curly, loose wavy and straight coat.