Question

Mendel proposed that the factor controlling any character is discrete and independent. This proposition was based on which of the following observations?

• A. Offsprings of $F_3$ generation of a cross made between the plants having two contrasting characters show blended characters of its parents
• B. Offsprings of a cross made between the plants having two contrasting characters shows only one character without any blending
• C. Offsprings of self-pollination of $F_1$ parents with the same contrasting characters show blended characters of its parents
• D. Offsprings of cross-pollination of parental generations having three contrasting characters show only one character with blending.

Answer 1

Answer: (B)

When Mendel crossed parents with two contrasting characters and observed in the $F_1$ generation, that only one character was expressed (the dominant one). On selfing the $F_1$ generation, the character which did not appear in $F_1$ generation appeared in the $F_2$ generation. This showed that there is no blending in the contrasting characters but they are discrete and independent. On the basis of this observation, Mendel proposed that the factor controlling any character is discrete and independent.