In wheat, dwarfism dominates over normal growth, 2 homozygous organisms were crossed
In wheat, dwarfism dominates over normal growth, 2 homozygous organisms were crossed with each other, how many plants with normal growth can be expected in F2?
Let’s designate the gene that determines the dwarfism of wheat plants as C, then the gene that determines the normal growth of wheat will be c.
By condition, two homozygous organisms were crossed with each other. Let us write them down, according to the introduced designation, as SS and ss. The first plants will dwarf growth and produce type C germ cells. The second plants (cc) will have normal growth and produce type c germ cells.
In F1 of these plants, all descendants will be Cc, which corresponds to dwarf growth. Such a hybrid will already produce two types of germ cells: c and C.
In F2 we get the following options:
dwarf wheat will make up 75% of the offspring (CC – 25% and Cc – 50%);
wheat plants with normal growth (ss) – 25%.
Answer: 25% of all resulting F2 plants will have normal growth.