Pain that occurs with a fever, nausea, and vomiting or loss of appetite may be a sign of inflammation or infection of the gallbladder (acute cholecystitis). Symptoms that may mean that a gallstone is blocking the common bile duct include: 1  Yellowing of the skin and the white part of the eyes (jaundice).  Dark urine.
Mendel concluded that biological inheritance is determined by factors that are passed from one generation to the next. Mendel also concluded that the principle of dominance states that some alleles are dominant and others are recessive.
Concept 9 Specialized chromosomes determine gender. People had long philosophized about the observed differences between males and females of a species. If one considers sex a trait, or set of traits, then it followed that sex is inherited. In 1905, closer study of meiosis revealed the chromosomal basis of gender. Scientists noticed an oddball pair among the homologous chromosomes lined up at the cell equator during reduction division.