In one type of plant, orange petals (o) are dominant over yellow petals (o) and tall stems (t) are dominant over short stems (t). complete a dihybrid cross for parents with the genotypes

Explanation:

Possible gametes of OOTt are OT and Ot.

Possible gametes of OoTt are OT, Ot, oT, and ot.

The punnet square is shown in the attached figure.

As per the punnet square there are six genotypes and two phenotyes.

The genotypes with ratios are:

OOTT = 2/16

OOTt = 4/16

OOtt = 2/16

Oott = 2/16

OoTT = 2/16

OoTt = 4/16

The two phenotypes "orange with tall stems" and "orange with small stems" will be present in 12:4 i.e. 3:1.

if your own plato the answer is b. the fern transitioned from sporophyte generation to gametophyte generation.