Genetics
Maddie Fetsko & Austin Futrell
What's genetic?
Branch of bioiogy that studies heredity (passing of characteristics from parents to offsprings).
Who discovered genetics?
Gregor Mendel, an Austrian scientist known as the father of genetics. He studied pea plants for genetic trait discovery. He was the first to succeed in predicting how traits would be transferred from one generation to the next.
Genetic Terms
Dominant and Recessive
-A dominance is observed as the trait of an organism that masks the the recessive gene. -Recessive is the trait of an organism that can be masked by the dominant trait.
Heterozygous and Homozygous
-Heterozygous is the pairing of two different alleles for one trait (Tt). -Homozygous is the pairing of two identical alleles for one trait (TT, tt).
Genotype and Phenotype
Genotype is the gene combination of an organism, heterozygous and homozygous traits. -Phenotype is the outwards appearance of an organism regardless of its genotype.
Punnett Squares
In the punnett square to the right, P represents the dominant gene of a purple flower and p represents the recessive gene of a white flower. When two heterozygous (Pp) cross the genotypical results of their offsprings are 25% PP, 50% Pp, ad 25% pp. The phenotypical results of their offsprings are 75% purple and 25% white.
Complex Patterns of Inheritance
Incomplete Dominance
-Phenotype of heterozygous individuals is intermediate between those of two homozygous. -Ex: A red and a white flower making an offspring that's pink.
Codominance
-Phenotypes of both homozygotes produced in heterozygous individuals (both alleles are expressed equally). -Ex: A red and a white flower making an offspring with a mixture of red and white pedals.
Multiple Alleles
-An inheritance pattern in which traits are controlled by more than two alleles. -Ex: Blood type.
Sex-Linked Traits
-Characteristics determined by genes on sex chromosomes. -Ex: Red/green colorblindness, hemophilia, male pattern baldness, and placement of sweat glands.