Answer:
The height of the plant is governed by the genes responsible for their genotype and phenotype expression. Two different plants can grow at the different height.
A friend states that pea plant can grow faster than corn plants. This idea can be investigated by scientific inquiry. Both the corn and pea plant should grow at the same environmental condition. The height of the plants should be measured for 3 to 4 generations. The plants should be allowed for test cross and self cross. The growth time of both the plants should be measured and compared to known their growth.