Cho các phép lai: I. Ab/aB × Ab/aB ; II. AB/ab × AB/ab; III. AB/ab × Ab/aB; IV. AB/ab × ab/ab.

* Hướng dẫn giải

Đáp án D.

$I. \frac{Ab}{aB}\times \frac{Ab}{aB}\to 1\frac{Ab}{Ab}:2\frac{Ab}{aB}:1\frac{aB}{aB}\to KH:1:2:1$

$II. \frac{AB}{ab}\times \frac{AB}{ab}\to 1\frac{AB}{AB}:2\frac{AB}{ab}:1\frac{ab}{ab}\to KH:3:1$

$III. \frac{AB}{ab}\times \frac{Ab}{aB}\to 1\frac{AB}{Ab}:1\frac{AB}{aB}:1\frac{Ab}{ab}:1\frac{aB}{ab}\to KH:1:2:1$

$IV. \frac{AB}{ab}\times \frac{ab}{ab}\to 1\frac{AB}{ab}:1\frac{ab}{ab}\to KH:1:1$