NOTES ON GENETICS GREGOR MENDEL WAS A MONK THAT WORKED WITH PEA PLANTS. MENDEL�S WORK WITH PEA PLANTS HELP SCIENTIST ANSWER MANY QUESTIONS ABOUT HEREDITY. MENDLES GENETICS ALL ORGANISMS HAVE TRAITS. THESE TRAITS ARE CONTROLED BY GENES. EACH ORGANISM INHERITS 2 GENES FOR EVERY TRAIT . ONE OF THE GENES THAT THE ORGANISM RECIEVES COMES FROM THE MOTHER AND THE OTHER COMES FROM THE FATHER. THERE ARE 2 FORMS OF GENES FOR EVERY TRAIT, ONE DOMINANT GENE AND ONE RECESSIVE GENE. DOMINANT GENE-SOMETIMES CALLED A STRONG GENE .IF PRESENT WHAT EVER                                THE LETTER REPRESENTS WILL BE EXPRESSED IN THE OFFSPRING                                 ONLY ONE OF THE GENES NEED TO BE PRESENT TO HAVE THE TRAIT                                  APPEAR. RECESSIVE GENE- WEAK GENE, IF PRESENT WILL NOT BE EXPRESSED. IN                                 ORDER FOR THIS GENE TO BE EXPRESSED BOTH GENES                                 HAVE TO BE PRESENT. SYMBOLS IN GENETICS LETTERS ARE USED TO IDENTIFY GENES IN GENETICS A CAPITAL LETTER IS USED TO DESCRIBE A DOMINANT GENE A LOWERCASE LETTER IS USED TO DESCRIBE A RECESSIVE GENE GENOTYPE- THE GENE COMBINATION OF THE ORGANISM HOMOZYGOUS BOTH GENES ARE THE SAME  EXAMPLE-  TT OR tt HETEROZYGOUS- BOTH GENES ARE DIFFERENT BUT OF THE SAME LETTERS                               EXAMPLE - Tt   or   Rr GENE EXPRESSION WHAT TRAITS SHOW IN AN ORGANISM IS THE ORGANISMS PHENOTYPE IF THE ORGANISM HAS A GENOTYPE OF Tt- THE PHENOTYPE IS WHAT EVER THE BIG T REPRESENTS. THE BIG T- IS A DOMINANT GENE IF WE APPLY THE RULES CORRECTLY. IF THE ORGANISM HAS THE GENOTYPE tt THEN THE ORGANISM HAS A PHENOTYPE OF WHATERVER THE SMALL t REPRESENTS. EXAMPLES T- TALL                       R- RED FLOWER t- SHORT                      r- WHITE FLOWER TT-- TALL                      RR---RED FLOWER Tt-- TALL                        Rr ---RED FLOWER tt-- SHORT                       rr--- WHITE FLOWER