AP Biology Exam Review Notes

Unit 1: Chemistry and Properties of Water

  • Water is a polar molecule due to unequal sharing of electrons, leading to partial charges (negative for oxygen, positive for hydrogen).

  • Hydrogen bonding is crucial for water's properties and interactions with biomolecules.

  • Key properties resulting from hydrogen bonds include:

    • Cohesion: Water molecules stick together, causing surface tension.

    • Adhesion: Water molecules cling to surfaces, aiding in transpiration in plants.

    • High specific heat: Water can absorb a lot of heat before changing temperature.

  • pH and Acids/Bases:

    • Acidic solutions have more hydrogen ions (pH < 7); basic solutions have more hydroxide ions (pH > 7).

Unit 1: Elements of Life

  • Important elements include: Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur (CHNOPS).

  • Monomers and Polymers: Key biomolecules and their building blocks:

    • Proteins (amino acids)

    • Carbohydrates (monosaccharides)

    • Nucleic acids (nucleotides)

  • Dehydration Synthesis: Building macromolecules by removing water; Hydrolysis: Breaking down macromolecules by adding water.

Unit 1: Macromolecules Overview

  • Carbohydrates: Include monosaccharides like glucose, disaccharides like lactose, and polysaccharides like starch, glycogen, cellulose.

  • Lipids: Non-polar molecules including fats (energy storage), phospholipids (cell membranes), and steroids (hormones).

  • Proteins: Made from 20 different amino acids; structure levels: primary, secondary (alpha helices/pleated sheets), tertiary, quaternary.

  • Nucleic Acids: DNA (genetic material) and RNA (protein synthesis).

Unit 2: Cell Structure and Function

  • Cells are the basic unit of life; organized into prokaryotic (simple, lack a nucleus) and eukaryotic (complex, have a nucleus) cells.

  • Cell Membrane: Selectively permeable, composed of the phospholipid bilayer.

  • Transport Mechanisms:

    • Passive transport: Does not require energy (diffusion, facilitated diffusion).

    • Active transport: Requires energy to move substances against gradients.

  • Cellular Processes: Mitosis and Meiosis (cell division); apoptosis (programmed cell death).

Unit 3: Genetics

  • Mendelian Genetics: Key principles include segregation and independent assortment of alleles during gamete formation.

  • Phenotype vs. Genotype: Phenotype is observable traits; genotype is the genetic makeup.

  • Non-Mendelian Inheritance: Incomplete dominance, codominance, polygenic traits, sex-linked traits.

  • Chromosomal Inheritance: Study of chromosome behavior in meiosis and mitosis; non-disjunction leads to disorders (e.g., Down syndrome).

  • Molecular Genetics: Details on DNA and RNA structure, functions, and replication processes.

Unit 4: Evolution and Diversity

  • Natural Selection: Mechanism driving evolution; variations provide competitive advantages.

  • Speciation: Allopatric (geographic barriers) vs. sympatric (without barriers); adaptive radiation results in diverse adaptations.

  • Phylogenetics: Study of evolutionary relationships; use of molecular evidence and characteristics like homologous structures to build phylogenetic trees.

  • Biodiversity: Importance of genetic, species, and ecosystem diversity; effects of extinction and conservation efforts.

Unit 5: Ecology

  • Population Dynamics: Factors affecting population size include births, deaths, immigration, and emigration.

  • Community Interactions: Symbiosis (mutualism, commensalism, and parasitism), competition, and coevolution.

  • Ecosystem Services: Basic services provided by ecosystems (photosynthesis, decomposition) essential for human life.

  • Succession: Primary vs. secondary succession after disturbances; ecosystems recover and change over time.

Study Tips

  • Focus on conceptual understanding and application of principles.

  • Use visuals like charts and diagrams to aid memory retention.

  • Practice with sample exams and review guides available through APBiosuccess.com and Learn Biology.

  • Form study groups to discuss complex topics and quiz each other.

Unit 6: Human Physiology

  • Human Body Systems:

    • Circulatory System: Transports nutrients, gases, hormones, and waste; consists of the heart, blood vessels, and blood.

    • Respiratory System: Facilitates gas exchange; involves the lungs and airways.

    • Digestive System: Responsible for nutrient breakdown and absorption; includes organs such as the stomach and intestines.

    • Nervous System: Controls body functions and responses; consists of the brain, spinal cord, and nerves.

Unit 7: Plant Physiology

  • Photosynthesis: The Process by which plants convert sunlight into chemical energy; occurs in chloroplasts.

    • Light Reactions: Capture sunlight and produce ATP and NADPH.

    • Calvin Cycle: Uses ATP and NADPH to synthesize glucose from carbon dioxide.

  • Plant Hormones: Control growth, development, and responses to stimuli; examples include auxins, gibberellins, and abscisic acid.

Unit 8: Biotechnology

  • Biotechnology Techniques:

    • DNA Cloning: Creating copies of DNA fragments for study or use.

    • CRISPR: A gene-editing tool that allows for precise modifications in DNA.

    • Gel Electrophoresis: A Technique for separating DNA or protein molecules based on size.

  • Applications: Genetic engineering, gene therapy, agricultural improvements, and medical advancements.