Biology

• Genetics


  The study of heredity
• Tetrads


  Homologous pairs
• Crossing-Over


  Exchange of DNA between chromosomes during prophase I
• Meiosis I


  Separation of tetrads
• Meiosis


  Process of forming gametes
• Law of Independent Assortment

  Two or more pairs of alleles segregate independently of one another during gamete formations
• Law of Segregation


  Members of each pair of alleles separate when gametes are formed
• Phenotype


  Expressed traits of an organism
• Genotype


  Genetic makeup of an organism
• Heterozygous


  Has two different alleles (example: Bb)
• Homozygous Recessive


  Allele that is not expressed when dominant is present (bb)
• Homozygous Dominant


  Allele that is expressed
• Alleles


  Different forms of a gene
• Genes


  Segments of DNA that code for proteins
• Trait


  Different forms of a character
• Character


  Heritable feature that varies among individuals
• Gamete


  Sperm and egg cells (haploid)
• Cytokinesis

  Division of the cytoplasm at the end of mitosis or meiosis
• Haploid

  Meiosis ends with haploid cells
• Diploid

  Meiosis starts with a diploid cell
• Chromatin


  A mixture of DNA and proteins (histones) that makes up the chromosomes
• Chromosomes


  Structure that carries genetic information in the form of genes