The AP Biology exam has three main sections: molecules and cells, heredity and evolution, and organisms and populations. AP Biology is the most popular Advanced Placement course in the natural sciences. In 2016 over 238,000 students took the exam, and the mean score was 2.85. Most colleges and universities have a science and lab requirement, so a high score on the AP Biology exam will sometimes fulfill this requirement. The distribution of scores for the AP Biology exam is as follows (2016 data): 5 - 6.6%. 4 - 21.0%.
1. vitamin A2 - a viscous alcohol that is less active in mammals than is vitamin A1. dehydroretinol. antiophthalmic factor, axerophthol, vitamin A, A-any of several fat-soluble vitamins essential for normal vision; prevents night blindness or inflammation or dryness of the eyes.. (Biochemistry) a vitamin that occurs in the tissues of freshwater fish and has a function similar to that of vitamin A. Formula: C20H28O.
1 Hemoglobin A is a tetramer with two alpha chains and two beta chains (a 2 b 2). 2  Hemoglobin A2. 3  This is a minor component of the hemoglobin found in red cells after birth and consists of two alpha chains and two delta chains (a 2 d 2). 4  Hemoglobin A2 generally comprises less than 3% of the total red cell hemoglobin.