Question

How do Mendel's experiment show that the
A. Traits may be dominant or recessive
B. Traits are inherited independently

Answer 1

Initially Mendel took 34 pairs of characters of pea plant then 22 and finally 7 characters were identified by him on four different chromosomes. He assigned the characters like flower colour, height of the plant, seed colour, flower position, pod shape, pod colour and the shape of the seed.
His whole experiments are based on the four chromosomes and seven traits.

Complete answer:

He worked on a pea plant that is Pisum sativum.
He crossed two pea plants with specific characters, and formulated two laws namely law of dominance and segregation according to the results of the cross.
He took T for the tall plant which has a dominant trait of tallness and t for the recessive trait of dwarfness.
He crossed them and made them produce their progeny and observed the ${F_1}$ generation for the progeny chromosome traits.
If the plant is taller or on the same height of the parent means it has TT genotype that is the DOMINANT trait.
If the new plant is shorter than the parent plant mean tt genotype which shows the recessive trait
Whereas for the independent inheritance, the cross was made between the plants of ${F_1}$ generation.
He showed that the TT and tt first segregate to T, T,t,t as four independent factors and then they are crossed with each other assorted the trait independently or randomly in ${F_2}$ generation.
It makes the four possible outcomes TT, Tt, Tt, tt.

Note:
Law of dominance - Pair of alleles are brought together in ${F_1}$ generation one of them (trait) expresses itself masking the other completely.
Law of independent assortment - In ${F_1}$ generation law of segregation occurs and shows independent dominant effect.