Question

Mendel crossed a pure white flowered recessive pea plant with a dominant pure red flowered plant. The first generation of hybrids from the cross should show

• A. 50% white flowers and 50% red flowers
• B. All red flowered plants
• C. 75% red flowered and 25% red flowered plants
• D. All white flowered plants

Answer 1

The correct option is B All red flowered plants

• A trait that fully manifests itself, in heterozygous condition, is referred to as the dominant trait and the allele controlling it is known as a dominant allele. The trait that does not express itself in heterozygous condition or whose effect is masked by the presence of a dominant trait is known as a recessive trait.
• Therefore, a cross between red-flowered pea plant (RR) and white-flowered pea plant (rr) will obtain all red-flowered plant (Rr) in $F_1$ generation as red color is dominant over recessive white color. If a white color was dominant characters, it would have expressed itself in $F_1$ generation. A cross between two pure breeding varieties produces a uniform $F_1$ generation of dominant individuals.

Thus, the correct answer is option B.