Can someone plz help me with this plz I beg u plz help me

What is a codon and where is it found

In a cross between individuals of a species of tropical fish, all of the male offspring have long tail fins, and none of the females possess the trait. mating two of the f1 fish fails to produce females with the trait. explain the inheritance pattern of the trait.

Which best describes a gene? a. a sister chromatid b. a chromosome c. a tetrad d. a piece of a chromosome