Education: studied botany + mathematics

Mendel's Pea Garden:

Pure breeding: achieved through self-fertilisation for many generations

Pea good: self-fertilising with stamens (male) & carpels (female)

7 famous pea traits: compare any two traits only at once to observe + maths

seed shape

seed colour

seed coat colour

pod shape

pod colour

flower position

stem length

Observations:

seed colour: P --> F1 hybrids: yellow, no green --> F2: Y:G(green) 3:1 ratio, green reappears

Dihybrid cross: two heterozygous traits are produced --> F1 hybrid: 2 heterozygous traits --> self-pollinate --> prediction using Punnett Square

Findings:

Dominance of yellow seeds over recessive green seeds --> Principle of Dominance (a type of heredity)

At least 2 traits present in F1 generation: since F2 contains both G & Y, even though only Y seeds are phenotypical in F1

3:1 ratio in F2: can be explained by combinations of the two traits to give 4 possible combinations

Probabilities: equal probabilities of passing alleles

Law of Segragation: Parental genes separate --> gametes --> random combinations --> possible combinations probabilities

Punnett Square: all gametes of parents --> all combinations for genetypes

F1 generation: heterozygous --> F2: same

Law of Indepedent Assortment: different traits are passed on independent of each other (proved wrong, due to co-existence of alleles on the same carrier gene --> depedent generation)

2 Heterozygous traits --> Punnett Square --> combinations 2^4=16 --> 9:3:3:1 for Dihybrid crosses based on assumption of independent assortment

Genetics:

Gene: a distinct unit of hereditary material

Allele: one form of a gene --> trait

Homozygote: all alleles are the same

Heterozygote: not all alleles are same --> different alleles

Genotype: genetic make-up of genes, alleles

Phenotype: physical trait expressed or presented in appearance

Gamete: half of all alleles of parent cell