Mendelian

• • Homologous pairs of chromosomes contain the same genes in the same locations.
  • Alleles are different versions of a gene.
  • Mendelian traits are controlled by a single gene and exhibit predictable patterns of inheritance.

  
• Mendelian Genetics - the study of inheritance of traits and the genes that control them

  • Mendelian Laws of Inheritance: Law of Dominance, Law of Segregation, Law of Independent Assortment
  • Mendelian Pattern of Inheritance: Autosomal Dominant, Autosomal Recessive, X-linked Dominant , X-linked Recessive
• Mendelian Laws of Inheritance

  • Dominant Allele - One allele (dominant) determines the phenotype in heterozygotes, expressed with a capital letter (e.g., R).
• Mendelian Laws of Inheritance

  • Recessive Allele - The allele that is not expressed in the presence of the dominant allele, expressed with a lowercase letter (e.g., r).
• Mendelian Laws of Inheritance

  • Law of Dominance - Offspring of the cross display only the dominant trait, masking the expression of the recessive trait

  
• Mendelian Laws of Inheritance

  • Law of Segregation -This law states that when an individual produces gametes (sex cells), the two copies of a gene separate so that each gamete receives only one of the two copies. The segregation of genes during gamete formation ensures that each offspring receives one copy of each gene from each parent.

  
• Mendelian Laws of Inheritance

  • Law of Independent Assortment - This law states that different pairs of genes segregate independently of each other during gamete formation. This means that the inheritance of one trait is not influenced by the inheritance of another trait.

  
• Autosomal dominant - is a pattern of inheritance for certain genetic traits or disorders that are caused by a dominant allele located on one of the autosomes.

  -Huntington's disease: A neurodegenerative disorder characterized by progressive motor dysfunction and cognitive decline.

  -Marfan syndrome: A connective tissue disorder affecting the skeletal, ocular, and cardiovascular systems caused by a mutation in FBN1.

  
• Autosomal recessive - two copies of the mutated gene (homozygous recessive) are necessary for the expression of the trait or disorder. Not typically seen in every generation

  -Cystic fibrosis: A disorder affecting the respiratory, digestive, and reproductive systems caused by a mutation in CFTR gene.

  -Tay-Sachs disease: A neurodegenerative disorder that primarily affects the nervous system caused by a mutation in HEXA gene in chromosome 15.

  -Sickle cell anemia: A blood disorder characterized by abnormally shaped red blood cells caused by a mutation in β-globin gene.

  
• X-linked dominant - a single copy of the mutated gene on one of the X chromosomes is sufficient to express the trait or disorder.

  
• X-linked recessive - is a pattern of genetic inheritance for traits or disorders caused by recessive alleles located on the X chromosome.

  -Hemophilia A and B: Blood clotting disorders.

  -Duchenne muscular dystrophy: A progressive muscle-wasting disorder.

  -Color blindness (most commonly red-green color blindness): A vision impairment affecting the perception of certain colors.