Question

The phenotype of $F_1$ progeny, when pure tall and dwarf plants are crossed together is _________.

• A. $50\%$ Tall and $50\%$ dwarf plants
• B. $100\%$ dwarf plants
• C. $75\%$ Tall and $25\%$ dwarf plants
• D. $100\%$ tall plants

Answer 1

The correct option is D

$100\%$ tall plants

If pure tall (TT) and pure dwarf (tt) pea plants are crossed, all tall plants are produced in F₁ generation. The tall palnt will produce only one type of gamete with the dominant allele (T). Similarly, the dwarf plant will produce only one type of gamete with the recessive allele (t). In the F1 generation, these two gametes will fuse and the offspring will be a heterozygous tall plant (Tt). This is because the allele for “tallness” is dominant over the allele for “shortness”.