Q14 of 60 Page 1

"A trait may be inherited, but may not be expressed." Justify this statement with the help of a suitable example.

A trait may be inherited, but may not be expressed. This statement is completely justified and can be seen by following example:


If we cross pure-bred tall (dominant) pea plant with pure-bred dwarf (recessive) pea plant we will get pea plants of F1generation. If we now self-cross the pea plant of F1 generation, then we obtain pea plants of F2 generation. Dwarf plants are not found in F1 generation but appeared in F2 generation. In the F1 generation, the dominant characteristic is Tall which appeared in F1 progeny but in F2 generation, presence of two recessive characteristics/ traits, the plants which appeared are dwarf. The ratio of tall plants to dwarf plants in F2 generation is: 3:1.


It proved that dwarfness which was lost in F1 generation, reappeared in F2 generation.


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(i) Write the type of mirror he should use.


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Draw a ray diagram to show the path of the refracted ray in each of the following cases:

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(i) passing through its optical center.


(ii) parallel to its principal axis.


(iii) directed towards its principal axis