Mendelian Genetics I Flashcards
Father of Genetics
Gregor Johann Mendel (1866)
Major postulates of transmission genetics.
Mendelian Genetics
garden pea (Pisum sativum)
Mendelian Genetics
Discrete units of inheritance (gene) exist and predicted their behavior during the formation of gametes (elementen).
Mendelian Genetics
units of inheritance.
Gene
Exist and predicted their behavior during the formation of gametes.
Elementen
Mendel’s postulates were accepted as the basis for the study of what is known as?
transmission of genetics
easy to grow and hybridize artificially.
Garden pea
self-fertilizing in nature.
Garden pea
Seven visible features (unit characters), each represented by two contrasting forms, or traits
Garden pea
Character: stem height: traits:tall and dwarf.
Garden pea
He selected six other visibly contrasting pairs of traits involving seed shape and color, pod shape and color, and pod and flower arrangement.
Garden pea
The genetic constitution of an individual (PP, Pp, pp)
Genotype
The outward appearance of an individual (purple, white).
Phenotype
The phenotype seen when two alternative alleles are present together (Pp: purple).
Dominant phenotype
The form of the gene that is expressed when two alternative alleles are present together.
Dominant allele
The phenotype that is only seen when two identical alleles are found together (pp: white)
Recessive phenotype
The form of the gene that is not expressed when two alternative alleles are present together.
Recessive allele
Having two identical alleles (PPor pp)
Homozygous
Having two different alleles (Pp)
Heterozygous
Mendel’s first three postulates. [3]
- Unit factor in pairs
- Dominance/ Recessiveness
- Segregation
Genetic Characters are controlled by unit factors that exist in pairs in individual organisms.
Unit factors in pairs
Because the factors occur in pairs, three combinations are possible: two factors fortall, two factors for dwarf,or one factor for each trait.
Unit factors in pairs
When two unlike unit factors responsible for a single character are present in a single individual, one unit factor is dominant to the other, which is said to be recessive.
Dominance/Recessiveness