Law of Segregation

Alleles separate such that each gamete has only one allele after Meiosis

Phenotype

Physical display of genes

Law of Independent Assortment

Inheritance of a gene is not dependent on another if the genes are on separate chromosomes.

Complete or Simple Dominance

When a recessive allele is masked by a dominate in the heterozygote

Incomplete Dominace

When heterozygotes have an intermediate phenotype between the two homozygotes

Codominance

When both alleles are equally expressed in the heterozygote

Epistasis

When one gene change the phenotype of another gene from a different chromosome

Polygenic Inheritance

When two or more genes work together to affect a trait

Recessive Genetic Disorders

Cystic Fibrosis, Tay Sachs Disease, Sickle Cell anemia

Dominant Genetic Disorders

Huntington's Disease, Achondroplasia

Sex-linked Genes

Genes carried on the "X" Chromosome

Human sex linked traits

Hemophilia, Colorblindness, Duschenna Muscular Dystrophy

Linked Genes

Genes carried on the same chromosome which are inherited together

Nondisjunction

When chromosomes don't separate during Anaphase I and Anaphase II

Barr Body

Structure that forms after one "X" chromosome is inactivated in a somatic cell

Gametes

Sex cells of an organism

Somatic Cells

Every cell other than the Gametes.

Locus

A gene's specific location along the length of a chromosome

Diploid Cell

Has two sets of chromosomal pairs (2n)

Haploid Cell

Has one set of chromosomes (n)

Zygote

Diploid cell that is an egg that is fertilized by sperm

Meiosis I

First step in which sexually reproducing organisms divide making half the number of chromosome sets as the original cell

Prophase I (Meiosis I)

Crossing over occurs, centrosome movement, spindle formation, nuclear envelope breakdown, Microtubules attach to the kinetochores

Metaphase I (Meiosis I)

Homologous pairs are arranged in the middle of the cell, Each pair has a kinetochore microtubule attached to it

Anaphase I (Meiosis I)

Breakdown of proteins between sister chromatids allowing the homologs to separate, homologs move towards opposite poles

Telophase I and Cytokinesis (Meiosis I)

Each half of the cell has a complete haploid set of chromosomes, cytokinesis

Meiosis II

Second step in which sexually reproducing organisms divide making half the number of chromosome sets from Meiosis I

Prophase II (Meiosis II)

Chromosomes once again move to the Metaphase plate

Metaphase II (Meiosis II)

Chromosomes are lined up at the Metaphase plate, microtubules extend from opposite poles

Anaphase II (Meiosis II)