Nondisjunction is a chromosomal mutation that produces an offspring with an incorrect number of chromosomes. This can result in disorders like downs syndrome.
A recessive trait is a trait that is unlikely to appear in a person. If a dad has brown hair, and the mom has blonde then the child will more than likely have brown hair because it is a dominant trait.
A dominant trait is one that will be more likely to appear in a person.
Somatic cells are body cells which don't get passed on. These cells can be changed through the environment, like using a tanning bed gives you radiation so they could change.
Germ cells are cells that have half the number of chromosomes than in a somatic cells. These cells are passed on during meiosis, and are what give you different mutations like brown hair.
Karyotype and how the genotype can change the phenotype
A karyotype is number of chromosomes a organism has, if one chromosome is different then it changes the genotype which determines what you will look like. This changes the Phenotype which is what you look like to the naked eye.
Kleinfetter's syndrome is a mutation in the sex chromosome mostly in males. This mutation gives them an extra X chromosome which gives them less testosterone. It cannot be inherited instead is a random chance, it is also recessive
Downs syndrome is a mutation in the 23rd chromosome in which an extra chromosome is added to the homologous pair. Downs is neither dominant nor recessive.
Colorblindness is a changing in the genotype which causes mostly males to not be able to see certain colors. This a recessive trait.
The lack of a second sex chromosome leaving only a X, this causes the person with this mutation to be infertile. This is a neither dominant nor recessive trait.