GENETICS PUNNETT SQUARES Gregor Mendel an Austrian monk

GENETICS & PUNNETT SQUARES

Gregor Mendel, an Austrian monk in the 1800 s, noticed the following while raising peas in his monastery's garden… • Pea plants of varying sizes • TALL plants • SHORT plants • Pod textures variances • SMOOTH pods • WRINKLED pods • Color variances • PODS of green and yellow • FLOWERS of white and purple

Mendel set out to understand how these traits were handed down to off-spring plants through controlling the pollination between plants… Doing so allowed for his discovery of many important GENETIC RULES • How something or someone looks does not always match what their genetic code might suggest! • Genotype – Actual genetic makeup • Phenotype – What they/it looks like • Traits that frequently show up – Dominant • Traits that show up less – Recessive • Combinations - Hybrids

Predictions using PUNNETT SQUARES • Each gene has two chances at a trait • Two Copies • Two Alleles • A HYBRID could carry an allele for a recessive trait even if you cannot see it EXAMPLE: A TALL plant, tall dominant parent, could have a recessive allele (short) This is the difference between GENOTYPE (Actual GENETIC MAKEUP) & PHENOTYPE (How It Appears)

PUNNETT SQUARES These are the 2 alleles of each parent plant crossed with one another and showing the 4 possible offspring. TT – Dominant Tall, tt – Recessive Short, Tt – Mixed Hybrid TT – Dominant Tall (Geno T, Pheno T) Tt – Mixed Hybrid (Geno H, Pheno T) tt – Recessive Short (Geno S, Pheno S) 1. 2. 3. 4. ____ ____ ____ ____

PUNNETT SQUARES These are the 2 alleles of each parent plant crossed with one another and showing the 4 possible offspring. TT – Dominant Tall, tt – Recessive Short, Tt – Mixed Hybrid TT – Dominant Tall (Geno T, Pheno T) Tt – Mixed Hybrid (Geno H, Pheno T) tt – Recessive Short (Geno S, Pheno S) 1. 2. 3. 4. ____ ____ ____ ____