Previous Theorists Pangenesis o All part of the body make seeds that are then collectd and transmitted to offspring o Spermists o Homunculus little man in sperm Father responsible for everything Ovists o Mom s egg entirely responsible for inheritance Sperm only stimulates egg to develop Blending Theory of Inheritance o Factors from both mom and dad Mendel o Father of genetics Physics taught him World is orderly place Hermaphrodite Plant animal that has reproductive organs normally associated with both male and female genders o Snails example of animal Mendel chose peas Peas have distinct characteristics Structure allowed for easy crosses where the parents could be controlled o Anther on end of pod contains the pollen grains plant sperm where the male gametes are produced o Ovary and ovule are contained within the pea of the plant Pollen o Contains two nuclei 2 sperm One sperm goes and fertilizes diploid cell diploid two sets of chromosomes haploid one set triploid three sets o Endo sperm nucleus provides food o Fertilized egg zygote Mendel Two types of crosses o Self fertilization Pollen and egg are derived from same plant o Cross fertilization Pollen and egg are derived from different plants Hybridization The mating or crossing between two individuals that contain DIFFERENT characteristics o Purple flowered plant X white flowered plant Hybrids o The offspring that result from hybridization Morphological characteristics of organisms Called characters or traits True breeder Variety that produces the same trait over several generations Traits Mendel studied Each of these had two possible outcomes of trait called variants o Height o Color of flower o Position axial v terminal o Color of seed o Seed shape o Pod color o Pod shape He first crossed only two at a time Called monohybridization Parents P TT x tt Offspring F1 Tt x Tt Next gen F2 TT x Tt x Tt x tt For all seven traits studied F1 only presented one trait o F2 showed a 3 1 ratio Every single time Data suggested a particulate theory of inheritance Alleles Different versions of same gene Homozygous Individual w two identical alleles of gene Heterozygous Individual w two different alleles of gene Genotype Specific allelic composition of individual Phenotype Outward appearance of individual