Human Genetics

Human genetics are studied using PEDIGREES, which diagram how a trait is inherited in a family. A pedigree helps us determine genotypes of the family members

A pedigree for the recessive allele that cause albinism. Albinos are humans that have no pigment, their skin is very pale and all their hair is white, including eyebrows and eyelashes.

This pedigree shows how albinism can be inherited over 2 generations.

Other animals can also be albinos, like this deer.

Human genetics can also be studied by looking at IDENTICAL TWINS, which help establish whether NATURE or NURTURE influences are traits.

Human Genetic Diseases

Albinism - inability to produce pigment, white hair and skin, autosomal recessive
Huntingtons - symptoms of mental illness appear late in life, autosomal dominant
Sickle Cell Disease - blood cells shaped abnormally, autosomal recessive
Tay Sachs - fat builds up in the brain of infants causes degeneration and early death, autosomal recessive
Hemophilia - bleeder's disease, inability of the blood to clot, sex linked recessive
Cystic Fibrosis - mucus builds up in lungs causing respiratory problems, autosomal recessive