Non-Mendelian Patterns

• In humans, females have two X chromosomes while males have one X and one Y chromosome.
• The sex-linked inheritance pattern is determined by the presence or absence of certain genes on the X chromosome.
• Color blindness is another example of a sex-linked trait that can be caused by mutations in specific genes located on the X chromosome.
• Hemophilia A is an example of a recessive sex-linked trait that affects blood clotting ability.
• Gregor Johann Mendel is known as the Father of Genetics as he serves as the foundation of the modern principles in genetics.
• Genotype refers to genetic makeup of an individual.
• Phenotype refers to the observable appearance of an organism as a result of its genotype.
• Before the creation of modern genetics, pre-genetic beliefs were that organisms originate from inanimate objects.
• Reginald Crundall Punnett created the Punnett square to depict the number and variety of genetic combinations.
• Further experiments in modern genetics resulted in inquiries that cannot be answered by Mendel's laws alone.
• Incomplete dominance is when neither trait of the parents is expressed in the offspring.
• Codominance is when both alleles are equally expressed in the phenotype.
• Multiple alleles is when a certain trait contains more than two alleles; however, an individual can only possess two.
• Polygenic inheritance is when a trait is controlled by multiple genes.
• Males are more affected by x-linked traits compared to females
• examples of polygenic traits are height, eye-color, and hair-color
• Incomplete dominance results in a third phenotype which is a blend between the two dominant phenotypes.