Mendelian Genetics Ch. 5 Sec.1 and 2

Gregor Mendel The basic laws of heredity were first formed during the mid-1800’s by an Austrian botanist monk named Gregor Mendel. Because his work laid the foundation to the study of heredity, Mendel is referred to as “The Father of Genetics.”

Heredity and Gregor Mendel Heredity: The passing of traits from parents to offspring. Mendel discovered the principles of heredity. Mendel studies pea plants. They were self-pollinating (have both male and female structures, so it can pollinate itself). Pea plants can also cross-pollinate (pollinate a different flower).

Mendel’ Pea Plants Mendel based his laws on his studies of garden pea plants. Mendel was able to observe differences in multiple traits over many generations because pea plants reproduce rapidly, and have many visible traits such as: Pod color Seed Color Plant Height Green Yellow Green Yellow Seed Shape Short Pod Shape Tall Wrinkled Round Smooth Pinched

Studying Pea Plants Mendel studied one characteristic at a time. A characteristic is a feature that has different forms in a population. The different forms of these characteristics are called traits.

Mendel’s Experiments Mendel saw some interesting traits appear when plants were crossed. The first generation offspring are called the F1 generation. The second generation offspring are called the F2 generation. Dominant traits are observed in the organism’s characteristics if present. Recessive traits are traits that are hidden if the dominate trait is present. Recessive traits can only be seen in the organisms if both alleles are recessive.

Mendel’s Observations

Traits and Inheritance Gene: One set of instructions for an inherited trait. Each parent gives their offspring one set of genes. The different forms of a gene are called alleles. Homozygous: When alleles from both parents are the same. HH or hh Called a purebred Heterozygous: When alleles from parents are different. Hh Called a hybrid

Genotype Vs. Phenotype Phenotype: An organism’s appearance (what you see: hair color, height, eye color etc.) Genotype: The genetic make-up of an organism– the alleles that are present for a trait. (Hh or AA)

Karyotype Photograph of an organism’s chromosomes.

Heredity Concept Map Heredity Use the following terms to complete the concept map below: Alleles parents Phenotype Genes Offspring genotype Characteristics dominant

Heredity Concept Map Heredity Parents genes Heredity Use the following terms to complete the concept map below: Alleles parents Phenotype Genes Offspring genotype Characteristics dominant Characteristics Parents genes offspring alleles dominant genotype phenotype