Question:
A student performed some crosses in plants and represented the result in the form of bar graphs as shown below. Each graph displays the phenotypic proportion of the progeny. Study the graphs and answer the questions :
(c) What conclusion can you draw from the results of bar graphs of crosses I and II ? Name the genetic principle illustrated.
A student performed some crosses in plants and represented the result in the form of bar graphs as shown below. Each graph displays the phenotypic proportion of the progeny. Study the graphs and answer the questions :
(c) What conclusion can you draw from the results of bar graphs of crosses I and II ? Name the genetic principle illustrated.
Show Hint
Cross I gives all tall, so tall is dominant. The principle is the Law of Dominance.
Updated On: Oct 23, 2026
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Solution and Explanation
Step 1: Read cross I
All 500 plants in cross I are tall and none is dwarf. So the tall character masks the dwarf character.
Step 2: Read cross II
In cross II there are 375 tall and 125 dwarf plants, a ratio of 3 : 1. The dwarf trait appears again, but only in one fourth of the plants.
Step 3: Conclusion and principle
The results show that the tall trait is dominant over the dwarf trait. The principle illustrated is the Law of Dominance.
Final Answer:
Tall trait is dominant over dwarf trait. The genetic principle illustrated is the Law of Dominance.
All 500 plants in cross I are tall and none is dwarf. So the tall character masks the dwarf character.
Step 2: Read cross II
In cross II there are 375 tall and 125 dwarf plants, a ratio of 3 : 1. The dwarf trait appears again, but only in one fourth of the plants.
Step 3: Conclusion and principle
The results show that the tall trait is dominant over the dwarf trait. The principle illustrated is the Law of Dominance.
Final Answer:
Tall trait is dominant over dwarf trait. The genetic principle illustrated is the Law of Dominance.
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