(b) P generation P generation Precocious Normal Normal Normal puberty ở Pp puberty ? pp puberty ? Pp puberty d pp Meiosis Meiosis P P Gametes (P P Gametes Fertilization Fertilization Half of the sons and Half of the sons and F, generation none of the daughters have precocious puberty. F, generation none of the daughters have precocious puberty. ½ Pp precocious puberty 2 Pp normal puberty ½ Pp precocious puberty ½ Pp normal puberty 2 pp normal puberty 2 pp normal puberty 2 pp normal puberty 2 pp normal puberty Conclusion: Both males and females can transmit this sex-limited trait, but it is expressed only in males.

Scallly, rough skin, or ichthyosls, is a x-linked recessie trait found in humans (X*a); normal skin is dominant (X*A). Mike has ichthyosls ad he marries Carol whao has normal skin. The y have three boys and two girls. their own daugther has ichthyosls and the other daugther does not. The edest son hs ichthyosls and the othr sons have normal skin. What are the chances that they have a daugther with ichthyosls? What are the chances that they have a son with ichthyosls? Mike's gamete alleles? Carol's gamete alleles?

Is the trait correct?

"Meiosis, oh meiosis, let me tell you what it means. It's a special kind of cell division with some funny little genes. It starts with a cell splitting in two, just like mitosis would; but from there, things get wild and wacky, and I'll tell you if I could. Instead of dividing once more, the cells each split again; creating four brand new cells, not just two like back then. And here's where the magic happens, with chromosomes all pairing up, then swapping bits of info, a dizzying process that can't be summed up. When all is said and done, those four new cells are not quite the same; they've got half the number of chromosomes, and a whole new genetic game. Meiosis, oh meiosis, it's a puzzle that's so much fun. And if you study it like I have, you'll see how it all gets done!"