Mendel's Laws of Heredity

Mendel's Laws of Heredity

Unit 4 Notes

Conclusions

Mendel concluded that biological inheritance is determined by factors that are passed from one genetation to the next. These factors that determine traits are called genes.

Alleles - different forms of genes, such as genes for height can either produce genes for tall plants or genes for short plants.

1st Law

Law of Segregation - every organism has two alleles of each gene and when gametes are produced the alleles separate.

Phenotype - the way an organism looks and behaves (tall or short)

Genotype - the allele combination of an organism (TT, tt, Tt)

1st Law

An organism is homozygous for a trait if the two alleles for the trait are the same.

(TT - homozygous dominant; tt - homozygous recessive)

An organism is heterozygous for a trait if its two for the trait are different (Tt).

2nd Law

Law of Independent Assortment - genes for different traits are inherited independently of eachother.

*In a dihybrid cross (two traits) you can see both of Mendel's Laws at work.