United States · College BoardSyllabus
Biology syllabus, dot point by dot point
Every dot point in the United States Biologysyllabus, with a focused answer for each one. Click any dot point for a worked explainer, past exam questions, and links to related dot points. Written by Claude Opus 4.8, Anthropic's latest AI.
Unit 1: Chemistry of Life
Module overview →- Which elements make up living organisms, and why is carbon central to the molecules of life?Topic 1.2 Elements of Life: describe the composition of macromolecules required by living organisms and the role of carbon, hydrogen, oxygen, nitrogen, phosphorus and sulfur in forming them.9 min answer →
- How are macromolecules built from and broken into monomers, and what are the four classes?Topic 1.3 Introduction to Biological Macromolecules: describe the chemical reactions that build and break biological macromolecules and the structure and function of the four classes.9 min answer →
- How is the structure of DNA and RNA suited to storing and transmitting genetic information?Topic 1.6 Nucleic Acids: describe the structural similarities and differences between DNA and RNA and explain how the directionality and base pairing of nucleic acids support their function.9 min answer →
- What are the properties of carbohydrates, lipids and proteins, and how do their subunits and bonds determine them?Topic 1.4 Properties of Biological Macromolecules: describe the properties of carbohydrates, lipids and proteins, including the directionality of their structures and how their subunits and bonding give rise to their functions.10 min answer →
- How do changes to the subunits of a polymer change the structure and function of a macromolecule?Topic 1.5 Structure and Function of Biological Macromolecules: explain how a change in the subunit composition or sequence of a polymer may affect its structure and function.9 min answer →
- How do the structure of water and hydrogen bonding give rise to the properties that make life possible?Topic 1.1 Structure of Water and Hydrogen Bonding: explain how the properties of water that result from its polarity and hydrogen bonding affect its biological function.9 min answer →
Unit 2: Cell Structure and Function
Module overview →- How does internal compartmentalization improve the efficiency of eukaryotic cells?Topic 2.10 Cell Compartmentalization: explain how internal membranes and membrane-bound organelles contribute to the compartmentalization of eukaryotic cell functions.9 min answer →
- Why does the surface-area-to-volume ratio limit cell size and shape the efficiency of exchange?Topic 2.3 Cell Size: explain the effect of surface-area-to-volume ratios on the exchange of materials between cells or organisms and the environment.10 min answer →
- How does the structure of a cell and its organelles relate to the functions the cell performs?Topic 2.2 Cell Structure and Function: explain how subcellular structures and organelles provide essential functions and how structure relates to function in cells.9 min answer →
- What are the subcellular components of cells and how do their structures suit their functions?Topic 2.1 Cell Structure: Subcellular Components: describe the structures and functions of the subcellular components and organelles of prokaryotic and eukaryotic cells.10 min answer →
- How do channel and carrier proteins move polar molecules and ions across the membrane without energy?Topic 2.7 Facilitated Diffusion: explain how the structure of channel and carrier proteins allows the facilitated diffusion of polar molecules and ions across a membrane.9 min answer →
- How does active transport build and use electrochemical gradients, and how does bulk transport move large material?Topic 2.9 Mechanisms of Transport: explain how active transport and bulk transport move ions and large molecules across membranes and establish electrochemical gradients.9 min answer →
- How does the structure of the membrane determine which substances can cross it?Topic 2.5 Membrane Permeability: explain how the structure of biological membranes influences selective permeability.9 min answer →
- How do passive and active transport move substances across the membrane, and how do they differ in energy use?Topic 2.6 Membrane Transport: describe the mechanisms that organisms use to transport large and small molecules across the membrane and the energy requirements of passive and active transport.9 min answer →
- How did membrane-bound organelles such as mitochondria and chloroplasts arise?Topic 2.11 Origins of Cell Compartmentalization: describe the similarities and differences in compartmentalization between prokaryotic and eukaryotic cells, and the evidence for the endosymbiotic origin of mitochondria and chloroplasts.9 min answer →
- How does the fluid-mosaic structure of the plasma membrane suit its role at the cell boundary?Topic 2.4 Plasma Membranes: describe the roles of each of the components of the cell membrane in maintaining the internal environment of the cell.9 min answer →
- How does tonicity determine the movement of water, and how do organisms osmoregulate?Topic 2.8 Tonicity and Osmoregulation: explain how concentration gradients of water and solutes affect the movement of water into and out of cells, and how organisms regulate their water balance.10 min answer →
Unit 3: Cellular Energetics
Module overview →- How do cells obtain, store and use energy, and what makes a reaction favorable?Topic 3.4 Cellular Energy: explain how cells use free energy, ATP and coupled reactions to drive endergonic processes, and how energy flows into and out of biological systems.9 min answer →
- How do cells release the chemical energy in glucose to make ATP?Topic 3.6 Cellular Respiration: explain how glycolysis, the Krebs cycle and oxidative phosphorylation release energy from glucose to make ATP, and how fermentation allows ATP production without oxygen.10 min answer →
- How do temperature and pH change the rate of an enzyme-catalyzed reaction?Topic 3.3 Environmental Impacts on Enzyme Function: explain how changes in temperature and pH affect enzyme structure and the rate of an enzyme-catalyzed reaction, including denaturation and optimum conditions.9 min answer →
- How do enzymes speed up reactions, and what controls the rate of an enzyme-catalyzed reaction?Topic 3.2 Enzyme Catalysis: explain how enzymes lower activation energy and how substrate concentration, enzyme concentration and inhibitors affect the rate of an enzyme-catalyzed reaction.10 min answer →
- How does the structure of an enzyme determine which reaction it catalyzes?Topic 3.1 Enzyme Structure: describe the structure of enzymes, the role of the active site, and how the structure of an enzyme determines its specificity for a substrate.9 min answer →
- How does photosynthesis capture light energy and store it as chemical energy in sugars?Topic 3.5 Photosynthesis: explain how the light-dependent reactions and the Calvin cycle capture light energy and use it to fix carbon dioxide into sugar.10 min answer →
Unit 4: Cell Communication and Cell Cycle
Module overview →- How do cells communicate with one another over short and long distances?Topic 4.1 Cell Communication: describe the ways cells communicate, including direct contact and chemical signalling over short and long distances.9 min answer →
- What are the phases of the cell cycle, and what happens in each?Topic 4.5 Cell Cycle: describe the phases of the cell cycle, including interphase and mitosis, and explain how the events of each phase produce two genetically identical cells.10 min answer →
- How do negative and positive feedback keep biological systems regulated?Topic 4.4 Feedback: explain how negative feedback maintains homeostasis and how positive feedback amplifies a response, using examples from cellular and organismal systems.10 min answer →
- How does a signal arriving at a cell get converted into a response inside the cell?Topic 4.2 Introduction to Signal Transduction: describe the reception, transduction and response stages of a signalling pathway, and the roles of receptors, ligands and second messengers.9 min answer →
- How is the cell cycle controlled, and what happens when that control fails?Topic 4.6 Regulation of the Cell Cycle: explain how checkpoints and regulatory molecules control progression through the cell cycle, and how loss of control leads to cancer.10 min answer →
- How do signal transduction pathways amplify a signal, and what happens when they are altered?Topic 4.3 Signal Transduction Pathways: explain how signalling pathways relay and amplify a signal to produce a response, and how mutations or chemicals that change the pathway affect the cell.10 min answer →
Unit 5: Heredity
Module overview →- How do chromosomes carry genes, and what happens when their inheritance goes wrong?Topic 5.6 Chromosomal Inheritance: explain the chromosomal basis of inheritance, including sex determination and the consequences of nondisjunction.10 min answer →
- How does the environment influence the expression of a genotype?Topic 5.5 Environmental Effects on Phenotype: explain how environmental factors can affect the phenotype produced by a given genotype.9 min answer →
- How does meiosis generate genetic variation among gametes?Topic 5.2 Meiosis and Genetic Diversity: explain how crossing over, independent assortment and random fertilization produce genetic variation.10 min answer →
- How does meiosis halve the chromosome number and produce gametes?Topic 5.1 Meiosis: explain how meiosis produces four haploid cells from one diploid cell, and how it differs from mitosis.10 min answer →
- How do Mendel's laws predict the inheritance of traits?Topic 5.3 Mendelian Genetics: apply the laws of segregation and independent assortment to predict genotype and phenotype ratios.11 min answer →
- How do inheritance patterns depart from simple Mendelian ratios?Topic 5.4 Non-Mendelian Genetics: explain inheritance patterns that depart from simple dominance, including incomplete dominance, codominance, sex linkage, polygenic traits and linkage.10 min answer →
Unit 6: Gene Expression and Regulation
Module overview →- How do biotechnology tools let us manipulate and analyze DNA?Topic 6.8 Biotechnology: describe the main biotechnology techniques (PCR, gel electrophoresis, restriction enzymes, sequencing) and explain how they are used.11 min answer →
- How is the structure of DNA and RNA suited to storing and carrying genetic information?Topic 6.1 DNA and RNA Structure: describe the structure of DNA and RNA and explain how it suits their role in storing and transmitting genetic information.10 min answer →
- How do cells with identical DNA become different cell types?Topic 6.6 Gene Expression and Cell Specialization: explain how differential gene expression produces specialized cell types from one genome.10 min answer →
- How do changes in DNA affect gene products and phenotypes?Topic 6.7 Mutations: explain the types of mutations and how they affect gene products, phenotype and the variation available to a population.10 min answer →
- How do cells control which genes are expressed and when?Topic 6.5 Regulation of Gene Expression: explain how gene expression is regulated in prokaryotes and eukaryotes, including operons and regulatory sequences.11 min answer →
- How is DNA copied accurately before cell division?Topic 6.2 Replication: explain how DNA is replicated semiconservatively, including the roles of the key enzymes and the leading and lagging strands.10 min answer →
- How is the information in a gene copied into messenger RNA?Topic 6.3 Transcription and RNA Processing: explain how RNA polymerase transcribes a gene into mRNA and how the primary transcript is processed in eukaryotes.10 min answer →
- How is the genetic code translated from mRNA into a protein?Topic 6.4 Translation: explain how the ribosome translates mRNA codons into a polypeptide, including the roles of tRNA and the genetic code.10 min answer →
Unit 7: Natural Selection
Module overview →- How does artificial selection compare with natural selection?Topic 7.3 Artificial Selection: explain how humans drive evolution through artificial selection and how it differs from natural selection.9 min answer →
- What features shared by all living things point to a common ancestor?Topic 7.7 Common Ancestry: describe the structural and molecular features shared by all organisms that indicate common ancestry.9 min answer →
- How do we know evolution is still happening today?Topic 7.8 Continuing Evolution: explain how ongoing examples such as antibiotic resistance and pesticide resistance show that evolution continues.10 min answer →
- What kinds of evidence support the theory of evolution?Topic 7.6 Evidence of Evolution: describe the lines of evidence (fossil, anatomical, molecular, biogeographical) that support evolution.10 min answer →
- What causes extinction, and how does it shape the diversity of life?Topic 7.11 Extinction: explain the causes of extinction, including mass extinctions, and its role in shaping biodiversity.9 min answer →
- How can we tell whether a population is evolving at a gene?Topic 7.5 Hardy-Weinberg Equilibrium: use the Hardy-Weinberg equations to calculate allele and genotype frequencies and test whether a population is evolving.11 min answer →
- What conditions are required for natural selection to occur?Topic 7.1 Introduction to Natural Selection: explain the conditions required for natural selection and how it leads to changes in a population.10 min answer →
- How do different modes of natural selection shape phenotype distributions?Topic 7.2 Natural Selection: explain how directional, stabilizing and disruptive selection change the distribution of phenotypes in a population.10 min answer →
- What scientific models explain how life could have originated on Earth?Topic 7.13 Origin of Life on Earth: describe the scientific models for the origin of life, including the RNA world and the evidence supporting them.10 min answer →
- How do phylogenetic trees represent evolutionary relationships?Topic 7.9 Phylogeny: interpret and construct phylogenetic trees and cladograms from shared characters and molecular data.10 min answer →
- What processes change allele frequencies in a population?Topic 7.4 Population Genetics: explain how natural selection, mutation, gene flow, genetic drift and non-random mating change allele frequencies.11 min answer →
- How do new species form from existing ones?Topic 7.10 Speciation: explain how reproductive isolation leads to speciation, including allopatric and sympatric speciation.10 min answer →
- Why is genetic variation within a population important for its survival?Topic 7.12 Variations in Populations: explain why genetic variation within a population is important for survival and the response to environmental change.9 min answer →
Unit 8: Ecology
Module overview →- Why is biodiversity important for the health and stability of ecosystems?Topic 8.6 Biodiversity: explain how biodiversity contributes to ecosystem stability and resilience.9 min answer →
- How do species interact within a community?Topic 8.5 Community Ecology: explain the types of interactions between species in a community and their effects on the species involved.10 min answer →
- How do natural and human disturbances disrupt ecosystems?Topic 8.7 Disruptions to Ecosystems: explain how natural and human-caused disruptions affect ecosystems and how ecosystems respond.10 min answer →
- How does population density affect the factors that limit growth?Topic 8.4 Effect of Density of Populations: distinguish density-dependent from density-independent factors and explain how each limits population size.9 min answer →
- How does energy flow through an ecosystem, and why is it lost between levels?Topic 8.2 Energy Flow Through Ecosystems: explain how energy flows through trophic levels and why energy is lost between levels.10 min answer →
- What determines how populations grow and how large they become?Topic 8.3 Population Ecology: explain exponential and logistic growth, carrying capacity, and the factors that regulate population size.11 min answer →
- How do organisms respond and behave in their environment?Topic 8.1 Responses to the Environment: explain how organisms respond to environmental cues through behavior and signalling, and how these responses affect survival and reproduction.9 min answer →