Iheritance/miosis

• Phenotype - what you can visibly see - freckles, hair color, dimples, etc.
• Genotypes are made up of alleles (versions of genes).  They are indicated by letters.

  • One dominant from mom, one dominant from dad = homozygous dominant (AA)
  • One dominant from one parent, one recessive from one parent = heterozygous (Aa)
  • One recessive from mom, one recessive from dad = homozygous recessive (aa)
• Inherit 2 alleles for each trait - one from mom and one from dad
• Dominant traits - mask a recessive trait if present
• Alleles - varying forms of a trait
• Preformation- people are preformed in gametes (sperm cells)
• Pangenesis - Darwin’s reproduction thought was that, body fluids combine and offspring are a result of blending traits between parents traits
• punnet squares are used to determine all the possible genotypes and phenotypes that offspring can inherit from their parents
• Being " pure " is having 2 dominant genes, or 2 recessive genes for a trait.
• Being " hybrid" is when you have a dominant and a recessive gene for a trait.
• P generation | Parental generation, the first two individuals that mate in a genetic cross
• F1 generation | The first generation of offspring obtained from a cross of two organisms.
• F2 generation | offspring of the F1 generation
• Law of Dominance | When an organism is heterozygous for a pair of contrasting traits, only the dominant trait can be seen in the organism.
• The Law of Segregation | Mendel's law that states that the pairs of homologous chromosomes separate in meiosis so that only one chromosome from each pair is present in each gamete
• Gamete


  Sex Cells (sperm/egg)
• Somatic Cell 


  Any cell of a living organism other than the reproductive cells.
• Haploid


  single set of chromosomes in an organism's cells

  
• Diploid


  TWO sets of chromosomes in an organism's cells (one form each parent)

  
• Chromosome

  Carry's genetic information in the form of genes

  
• Centromere


  The region of a chromosome to which the microtubules of the spindle attach

  
• Sister chromatids


  The identical copies (chromatids) formed by the DNA replication of a chromosome

  
• Homologous chromosomes


  chromosomes which contain the same genes in the same order along their chromosomal arms

  
• Locus (Loci)


  pecific, fixed position on a chromosome where a particular gene or genetic marker is located

  
• Genes


  the basic physical and functional unit of heredity. Made of DNA

  
• Alleles


  variations of genes, leading to diverse traits such as eye color.

  
• Autosomes


  one of the numbered chromosomes, not the sex chromosomes.

  
• Sex chromosomes


  chromosome involved in sex determination (X/Y)

  
• Crossing Over


  parts of the chromosome can be switched. The two chromosomes contain the same genes, but may have different forms of the genes.

  
• Spindle Fibers


  apparatus is the cytoskeletal structure of eukaryotic cells that forms during cell division to separate sister chromatids between daughter cells

  
• Centrosome


  organize the microtubules and provide a structure to the cell. makes the thing that pulls the chromatids apart during cell division.

  
• Cytokinesis


  the cytoplasmic division of a cell at the end of mitosis or meiosis, bringing about the separation into two daughter cells.

  
• Interphase (G1, S, G2)


  G1 phase (cell growth), followed by S phase (DNA synthesis), followed by G2 phase (cell growth)

  
• Meiosis I (PMAT-I)


  begins with one diploid parent cell and ends with two haploid daughter cells. This results in halving the number of chromosomes in each cell
• Meiosis II (PMAT-II)


  starts with two haploid parent cells and ends with four haploid daughter cells
• Nondisjunction


  the failure of one or more pairs of homologous chromosomes or sister chromatids to separate normally during nuclear division, usually resulting in an abnormal distribution of chromosomes in the daughter nuclei.