Inheritance

Inheritance

1. Genes

   • alleles
     • alleles are different versions of a gene that produce a variation of the characteristic
     • heterozygous-different allele on both chromosomes
     • homozygous-same allele on both chromosomes
     • dominant or recessive, dominant masks the effect of a recessive
   • inside a cell there is a nucleus which contains chromosomes
     • there are 2 copies of chromosomes, each copy has the same genes
       • a gene is a short piece of DNA coded for a certain characteristic

2. Monohybrid Inheriance

   • when a characteristic is controlled by a single gene
   • a punnett square or family pedigreecan be used to understand how alleles are inherited

3. Genetic Disorders

   • the result of inheriting gene mutations (a change in a gene's DNA)
   • sickle cell disease-caused by having 2 copies of a recessive allele for the heomoglobin gene, causes red blood cells to become sickle cell shaped, feel weak and tired, sudden pains due to clumps blocking blood flow
   • cystic fibrosis-caused by having 2 copies of a recessive allele for a cell membrane protein, affects movement of fluid in and out of cells which forms mucus in the lungs, increases risk of lung infections, breathing difficulties as airways are blocked, weight loss as enzymes are blocked from reaching the digestive system
   • caused by a faulty allele