Mitosis and Meiosis

Meiosis has two rounds of genetic separation and cellular division while mitosis only has one of each. In meiosis homologous chromosomes separate leading to daughter cells that are not genetically identical. In mitosis the daughter cells are identical to the parent as well as to each other.

Nondisjunction

The failure of one or more pairs of homologous chromosomes or sister chromatids to separate normally during nuclear division

Recessive Genes

A gene that is phenotypically expressed in the homozygous state but has its expression masked in the presence of a dominant gene.

Dominant Genes

A gene that is expressed phenotypically in heterozygous or homozygous individuals

Somatic Cell

Cells of a living organism other than the reproductive cells.

Germ Cell

A cell containing half the number of chromosomes of a somatic cell and able to unite with one from the opposite sex to form a new individual

Karyotypes

The number and visual appearance of the chromosomes in the cell nuclei of an organism or species.

how the genotype can change the phenotype?

Genotype is found can affect the expression of that genotype, and the environment can affect the phenotype. Genes can also be pleitropic when they affect more than one trait. The single base pair mutation that lead to sickle cell anemia is a classic example.

Kleinfetter's syndrome

Kleinefelters syndrome is a genetic condition in which a male is born with an extra copy of the X chromosomes. It's also called XXY syndrome. This syndrome isn't inherited, but rather occurs only as a result of a random genetic error after conception. Males born with Kleinfelters syndrome may have low testosterone and reduced muscle mass, facial hair, and body hair. Most males with this condition produce little or no sperm. Treatment may include testosterone replacement and fertility treatment. Inheritance Someone can obtain this genetic disorder by inheriting an extra X chromosome. It is a chromosomal disorder that affects only males. This disorder is neither dominant or recessive. It is the result of a trisomy; it is usually the cause of non- disjunction of sex chromosomes during meiosis.

Down Syndrome

Down syndrome is a genetic disorder caused when abnormal cell division results in extra genetic material from chromosome 21. Down syndrome causes a distinct facial appearance, intellectual disability, developmental delays, and may be associated with thyroid or heart disease. Down syndrome is neither a dominant or recessive trait because it is just an error in the "translation" process of the 21st chromosome.

Colorblindness

A reduced ability to distinguish between certain colors. The condition is often inherited. Other causes include certain eye diseases and medications. More men than women are affected. Color blindness usually involves the inability to distinguish between shades of red and green. There is no treatment for inherited color blindness. If color blindness is caused by another condition, treating the underlying cause can help. The essence you should know is, that red-green color blindness is a sex linked recessive trait and blue-yellow color blindness is a autosomal dominant trait. sex linked: encoded on the sex chromosome X; men only have one of them (XY) compared to women (XX).

Turner's disease

A chromosomal disorder in which a female is born with only one X chromosome. Turner syndrome results from a missing or incomplete sex chromosome. Symptoms include short stature, delayed puberty, infertility, heart defects, and certain learning disabilities. Treatment involves hormone therapy. Fertility treatment may be necessary for women who want to become pregnant. Turner Syndrome is neither dominant nor recessive. This is because the chromosomal pair would be XO instead of XX like it should be. This would cause the disease to be chromosomal, not genetic.