Page 56 - Biology - XII

Mendelian Inheritance, Pedigree
5 Mendelian Inheritance, Pedigree
Charts of Genetic Traits
Charts of Genetic Traits

EXPERIMENT - 10

Objective
To verify Mendel’s Law of segregation and independent assortment.

Principle/Theory
Gregor Johann Mendel is the father of genetics. Mendel’s laws of inheritance is based on the experimental study
of Gregor Johann Mendel as proposed in the year 1865. He studied the inheritance of contrasting traits of ‘Pisum
sativum’ (garden pea). The seven diff erent contracting traits chosen by him are shown below.
(a) Law of dominance. It states that out of the two contrasting factors representing a character in a hybrid,
only one is able to express itself. It is called dominant factor. The other factor is unable to express itself
in the presence of dominant factor. It is called recessive factor.
(b) Law of segregation. It states that the two alternative factors for each character separates and
segregates during the formation of gametes; and passes on to the gametes. Each factor has an equal
chance of being transferred to the off spring.

Dominant Round Recessive

Seed character Cotyledon colour Yellow Green
Wrinkled
Seed shape

Coat colour
White
Grey
Pod character Pod shape Infl ated Constricted

Yellow
Green
Pod colour

Position of pod Axial Terminal
Stem character

Stem length Tall Dwarf

Fig: 10.1: Seven traits of pea plant studied by Mendel
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