Nondisjunction: the failure of one or more homologous chromosomes to properly separate, causing an abnormal chromosome or chromosomes in the offspring.
Recessive genes: genes that aren't as strong or prominent as a dominant gene; for example, blue eyes
Dominant genes: Genes that are stronger and more prevalent within the pair
Somatic Cell: Skin cells
Germ Cell: the sexual reproductive cells
MITOSIS VS MEIOSIS
Chart representing the differences between mitosis and meiosis
Karyotype, Genotype, Phenotype, and how they affect each-other
Karyotype is your chromosomal patterns (your 21st chromosomes, and sex chromosomes for example). Genotypes are the way you are composed (what characteristics you'll have, what traits you get from your mom/dad). Both of these affect the Phenotype, which is your physical appearance. Karyotype deals with chromosomes, so if your 21'st chromosome is changed, then you will develop down syndrome, which has a specific effect on your phenotype. Your genotypes are the coding or your appearance, so if you have the specific mutation in your MC1R genotype located your 16th chromosome, you'll have red hair.
So what causes birth defects such as Kleinfetters, downs, turners, and colorblindness?
Birth defects are usually caused by 'mutations' or errors in your chromosomal codes. Kleinfetters syndrome is when a man has an extra X chromosome, instead of its usually X and Y. This usually happens when the genetic material in an sperm splits unevenly. This can cause more feminine characteristics in males, such as larger breasts, hips, less body hair than normal, etc. This would be caused by a germ cell
Down syndrome is caused by an error in cell division that causes an extra 21st chromosome. This cant be really tied to any direct source or cause. It mostly affects males. This would be a Germ cell.
Turner Syndrome is a genetic disorder than effects females. Female chromosomes usually look like XX, but for this syndrome part of one of the X's is missing. The most common symptoms are shortness and lack of ovarian function. This is also a germ cell.
Colorblindness is caused by an absence of function in one of the red blue or green light cones in a persons eyes that help see color. If you don't have one of these cones then you are colorblind. It is a genetic disorder that mostly affects males. This is a germ cell.