Genetics and Gregor Mendel

Genetics- the study of heredity I. Gregor Mendel & Pea Plants A. Austrian monk who began studying garden pea plants in 1860’s. B.Known as the “Father of Genetics” C. Used his background in math, biology, and physics to disprove the Blending Hypothesis.

D. Why did he use garden pea plants? 1.can be cross pollinated 2.produce large numbers of offspring 3.breed quickly 4.Easy to care for

II.Mendel’s Laws A.Law of segregation- each pair of alleles separates during meiosis (gamete formation) B.Law of Dominance- when 2 alleles are different, one allele can control the trait (dominant allele) and the other allele can be hidden (recessive allele) C.Law of Independent Assortment- gene pairs segregate into gametes randomly and independently of one another

III. Language of Genetics A. allele- different versions of genes for the same trait. B. Genotype- actual genetic makeup, occurs in pairs using capital letter for dominant trait and lowercase for recessive trait. (T=tall, t= short)

C. Phenotype – the observable trait (short, tall) D. homozygous (pure bred)- organism that have the same alleles for a trait.(TT, tt, BB, bb) E. heterozygous (hybrid)- orgamism that have different alleles for a trait. (Tt, Bb)

IV.Genetic Crosses A.Punnett Square- used to predict genetic crosses. B. Monohybrid cross- one factor cross  1.write a key for the trait  2.write the parents being crossed  3.do Punnett Square  4.write the genotype  5.write the phenotype

Mendel’s F 1 Crosses on Pea Plants

Mendel’s Seven F 1 Crosses on Pea Plants Mendel’s F 1 Crosses on Pea Plants