Question

What is incorrect in the following Mendelian traits?

| Character| Dominant| Recessive
---|---|---|---
A.| Height| Tall| Dwarf
B.| Seed colour| Green| Yellow
C.| Flower position| Axillary| Terminal
D.| Flower colour| Violet| White

Answer 1

When plant height is considered, the dominant trait is tall whereas the recessive trait is dwarf. Similarly, for seed colour, the dominant trait is yellow whereas the recessive trait is green.

Complete answer:
Mendel worked with several plants and found success in garden pea (Pisum sativum). He selected seven pairs of contrasting characters for his experiment.
They are as follows:

| Character| Dominant| Recessive
---|---|---|---
1.| Stem height| Tall| Dwarf
2.| Flower position| Axial| Terminal
3.| Pod colour| Green | Yellow
4.| Pod shape| Inflated | Constricted
5.| Seed colour| Yellow | Green
6.| Seed shape| Round | Wrinkled
7.| Flower colour| Violet| White

Hence, the correct answer is option (B).

| Character| Dominant| Recessive
---|---|---|---
B.| Seed colour| Green| Yellow

Additional information:
Gregor Johann Mendel was a mathematician who worked with several plants and honey bees. He found success in garden pea (Pisum sativum) and rajma (Phaseolus vulgaris). However, he couldn’t prove his laws. In 1900, Hugo de Vries, Carl Correns and Eric Von Tschermark rediscovered Mendel’s law.

Mendel selected garden pea as an experimental material because;
- They are annual plants.
- They strictly self-pollinate.
- Show large number of clear contrasting characters
- Pea flowers are relatively large which facilitates emasculation and pollination
- They are easy to grow and maintain.

Mendel stated three laws- Law of dominance, Law of segregation and law of independent assortment. Among these, Law of segregation is universally accepted. It is the only law without any exception. It states that each character consists of two alleles which segregate during the formation of gametes and only one of the two alleles from each parent combines during fertilization to form the character of the progeny.

Note: Mendel achieved success with garden pea because most of the characters selected by Mendel were qualitative characters (colour, shape, etc), unlike his predecessors who mostly worked with quantitative characters (height in cm etc).