Question

Mendel chose contrasting traits in Pea
A. Three
B. Two
C. One
D. Seven

Answer 1

Hint: Mendel selected 7 pairs of contrasting traits. The traits which always appear in two opposing conditions, one dominant and other recessive are called contrasting traits.

Complete answer:
Gregor Johann Mendel, the father of Genetics, discovered the principles of heredity through the experiments on the pea plant. Mendel carried out hybridization experiments on garden pea, Pisum sativum for seven years and proposed the laws of inheritance. Initially he took 34 pairs of varieties of pea plant, then 22 but ultimately worked with only 7 pairs of varieties. The characters differed as flower colour, flower position, stem height, pod shape, pod colour, seed shape, seed colour, etc. All the selected varieties were pure lines or true breeding, i.e., they were pure and bred true or gave offspring resembling the parents. Mendel conducted various types of cross breeding experiments and then allowed the offspring to self breed.

Characters of pea picked up by Mendel

S.No	Character	Dominant	Recessive
1.	Stem height	Tall (T)	Dwarf (t)
2.	Flower position	Axial (A)	Terminal (a)
3.	Pod colour	Green (G)	Yellow (g)
4.	Pod shape	Inflated (I)	Constricted (i)
5.	Seed shape	Round (R)	Wrinkled (r)
6.	Seed cotyledon colour	Yellow (Y)	Green (y)
7.	Flower colour/Seed coat colour	Violet (V)	White (v)

So, the correct answer is option D.

Note: Mendel selected 14 true breeding pea plant varieties, as it is an easy growing, naturally, self-fertilizing and it is well suited for artificial cross-pollination, therefore, hybridization is easily accomplished. The pair of contrasting characters of pea plant do not blend to produce intermediate types and can be traced through successive generations without confusion.