Which of the following is a dominant trait among the characters chose…

The correct answer is Option (3) → Violet flower colour

Mendel chose seven characters of the garden pea, each with two contrasting traits. In his crosses the F₁ always showed only one of the two traits; that trait is the dominant one. In Table 4.1 the dominant trait is written first in each pair: violet over white flower, axial over terminal flower position, inflated over constricted pod and green over yellow pod.

Option (1) Yellow pod colour — Incorrect. For pod colour, green is dominant and yellow is recessive (Green/yellow in Table 4.1).

Option (2) Terminal flower position — Incorrect. For flower position, axial is dominant and terminal is recessive.

Option (3) Violet flower colour — Correct. For flower colour, violet is dominant over white; this is also the trait used in Figure 4.5 (W for violet, w for white).

Option (4) Constricted pod shape — Incorrect. For pod shape, inflated is dominant and constricted is recessive.

Note: Seven rows of a small table hold the answer to this question and to many others like it. Learn the table pair by pair; it pays back far more than the time it takes.

NCERT Extract:
Mendel’s Laws of Inheritance – “… Mendel selected 14 true-breeding pea plant varieties, as pairs which were similar except for one character with contrasting traits. Some of the contrasting traits selected were smooth or wrinkled seeds, yellow or green seeds, inflated (full) or constricted green or yellow pods and tall or dwarf plants (… Table 4.1).”
Inheritance of One Gene – “… … violet colour flower (W) is dominant over white colour flower (w).”

Table 4.1: Contrasting Traits Studied by Mendel in Pea

S.No.	Characters	Contrasting Traits
1.	Stem height	Tall/dwarf
2.	Flower colour	Violet/white
3.	Flower position	Axial/terminal
4.	Pod shape	Inflated/constricted
5.	Pod colour	Green/yellow
6.	Seed shape	Round/wrinkled
7.	Seed colour	Yellow/green