Gregor Mendel – the father of genetics Ch 11: Intro to Genetics Pgs Block 1

Gregor Mendel: Born in 1822 Was a priest Studied science and mathematics at the University of Vienna. Teacher Worked with pea plants.

Fertilization Def. – when the male and female reproductive cells combine to form a new embryo.

Self-Pollinating When the male reproductive cell of a plant joins with the female reproductive cell of the same plant.

True-breeding plants Def. – if these plants were allowed to self-pollinate then they would produce offspring identical to themselves.

True-breeding plants in Mendel’s experiments: Mendel wanted to cross two individuals that were different from each other to see what would happen. Example: tall and short

Mendel’s work: Mendel began with true-breeding stocks of pea plants (P generation). Removed all male parts from the flowers to prevent self fertilization. Then controlled which plants would be crossed with one another.

Cross Pollination Mendel took the pollen from one plant and applied it to another plant of his choosing.

Trait Def. – a characteristic used to describe an organism. Examples: brown hair, blue eyes

3 Generations of plants: P generation – parent generation. Members of this generation are homozygous or pure- bred. F1 generation – cross of P generation results in the F1 generation. Members of this cross are heterozygous or hybrids. F2 generation – cross of F1 generation results in the F2 generation.

Mendel’s Principles: Units called genes determine biological characteristics. For each gene, an organism receives one allele from each parent. If an organism receives two different alleles for the same trait, one is dominant over the other. Some genes segregate independently.

Gamete formation: During gamete formation different copies of a given allele are separated into different gametes. A plant that is heterozygous for height (Tt) will have some gametes with a T in it and the rest will have a t in it.

Gametes: Reproductive cells. Human – egg and sperm.