Principles of Inheritance and Variation
1. Introduction
Inheritance = transfer of characters from parents to offspring.
Variation = differences among individuals.
Mendel = Father of Genetics (studied pea plant).
2. Why Mendel chose Pea Plant (Pisum sativum)?
- Short life cycle
- Large number of seeds
- Clear contrasting characters
- Self-pollinating but can be cross-pollinated
- Easy to grow
3. Mendel’s Seven Characters
Flower colour: Purple/White
Seed shape: Round/Wrinkled
Seed colour: Yellow/Green
Pod shape, Pod colour, Flower position, Stem length.
4. Important Terms
Gene, Allele, Dominant, Recessive, Genotype, Phenotype, Homozygous, Heterozygous.
5. Law of Dominance
In Aa, only dominant allele expresses.
6. Law of Segregation
Alleles separate during gamete formation.
7. Monohybrid Cross
1. Introduction
Inheritance = transfer of characters from parents to offspring.
Variation = differences among individuals.
Mendel = Father of Genetics (studied pea plant).
2. Why Mendel chose Pea Plant (Pisum sativum)?
- Short life cycle
- Large number of seeds
- Clear contrasting characters
- Self-pollinating but can be cross-pollinated
- Easy to grow
3. Mendel’s Seven Characters
Flower colour: Purple/White
Seed shape: Round/Wrinkled
Seed colour: Yellow/Green
Pod shape, Pod colour, Flower position, Stem length.
4. Important Terms
Gene, Allele, Dominant, Recessive, Genotype, Phenotype, Homozygous, Heterozygous.
5. Law of Dominance
In Aa, only dominant allele expresses.
6. Law of Segregation
Alleles separate during gamete formation.
7. Monohybrid Cross
