Mendelian Genetics

What are the 3 principles of Mendelian genetics?

The 3 principles of Mendelian genetics are:
a) Law of Dominance
b) Law of Segregation
c) Law of Independent Assortment

Q2

Which allele is dominant and which one is recessive? And on what basis is it decided?

A dominant allele produces a dominant phenotype in individuals who have one copy of the allele, which can come from just one parent. For a recessive allele to produce a recessive phenotype, the individual must have two copies, one from each parent. An individual with one dominant and one recessive allele for a gene will have the dominant phenotype. They are generally considered “carriers” of the recessive allele: the recessive allele is there, but the recessive phenotype is not.

Q3

Why did Mendel choose garden peas for his experiments?

Mendel selected garden pea for his experiments due to the following reasons:
(i) The plant is neither too big nor too small, i.e. it can be easily handled.
(ii) It has many contrasting characters.
(iii) Pea flowers are cleistogamous (remain enclosed).
(iv) In pea flowers, self and cross-pollination both may be affected.
(v) A large number of offspring is produced after a single cross.
(vi) Cycle is short.
(vii) Flowers are bisexual and homogamous.
(viii) It has less number of chromosomes.
(ix) Garden pea plant does not show incomplete dominance.
(x) Experiments may be conducted in simple laboratory conditions.