Subjects › Biology (High School)
High School Biology: Learn It by Talking It Through
This course covers the standard high school biology sequence: the chemistry of life, cell structure and function, genetics and molecular biology, evolution, ecology, classification, and an overview of human body systems. It starts from basic middle school science and builds up, so no prior biology or chemistry coursework is assumed.
Instead of reading through chapters, you talk through each idea with a tutor that asks questions rather than lectures. You explain what a cell membrane does, predict the outcome of a cross, or work out why a population levels off at carrying capacity, and the tutor follows up based on what you actually said, catching gaps before they turn into confusion later on.
Who it is for
- High school students taking biology for the first time, in class or independently
- Students preparing for a biology final or state end-of-course exam who want to check for gaps
- Homeschool students following a standard biology scope and sequence
- Parents who want a way to see what their student actually understands, not just what they've read
- Teachers looking for a review tool that makes students explain their reasoning, not just pick an answer
What you will be able to do
- Explain how cell structures, membrane transport, and enzymes support life at the cellular level
- Trace how DNA is copied, transcribed, and translated into proteins, and predict effects of mutations
- Use Punnett squares and pedigrees to predict inheritance patterns, including non-Mendelian cases
- Explain how natural selection and population genetics lead to adaptation and speciation
- Read a food web or energy pyramid and explain energy flow and nutrient cycling in an ecosystem
- Describe how major human organ systems maintain homeostasis through feedback loops
A taste of a lesson on Cell Membrane and Transport
The tutor asks, you answer, and it works from what you actually said. No videos to sit through.
The 29 topics in Biology (High School)
Each topic builds on the ones before it. The tutor checks what you already know and starts there.
Scientific Method and Biological Inquiry
Introduces the process of scientific inquiry: observation, hypothesis formation, experimental design (controls, variables, replication), data collection, and drawing conclusions. Covers what makes a claim testable and how biology uses evidence to build theories.
Characteristics of Life
Covers what distinguishes living things from non-living: organization (cells), metabolism, homeostasis, growth and development, reproduction, response to stimuli, and evolutionary adaptation. Establishes the unifying themes of biology.
Atoms, Bonds, and Water
Covers atomic structure basics, ionic and covalent bonds, and why water's polarity gives it properties (cohesion, adhesion, high specific heat, solvent ability) essential to life. Explains pH and acid/base basics as they relate to biological systems.
Biological Macromolecules
Covers the structure and function of carbohydrates, lipids, proteins, and nucleic acids. Explains monomers/polymers, dehydration synthesis and hydrolysis, and how each macromolecule's structure relates to its role in living organisms.
Builds on Atoms, Bonds, and Water
Enzymes and Metabolism
Covers how enzymes act as catalysts, the induced-fit model, activation energy, and factors affecting enzyme activity (temperature, pH, concentration, inhibitors). Connects enzyme function to cellular metabolism.
Builds on Biological Macromolecules
Cell Structure and Organelles
Covers prokaryotic vs eukaryotic cells, and the structure/function of major organelles (nucleus, mitochondria, ER, Golgi, ribosomes, lysosomes, chloroplasts, cytoskeleton). Compares plant and animal cells.
Builds on Biological Macromolecules
Cell Membrane and Transport
Covers the fluid mosaic model of the plasma membrane, and mechanisms of transport: diffusion, osmosis, facilitated diffusion, active transport, and endo/exocytosis. Explains tonicity and its effect on cells.
Builds on Cell Structure and Organelles
Energy in Cells: Overview
Introduces ATP as the energy currency of the cell and the concept of energy flow through photosynthesis and cellular respiration as complementary processes, setting up the two topics that follow in more depth.
Builds on Enzymes and Metabolism, Cell Structure and Organelles
Photosynthesis
Covers the light-dependent reactions and Calvin cycle at a conceptual level, the role of chlorophyll and chloroplasts, and the overall equation converting light energy, water, and CO2 into glucose and oxygen.
Builds on Energy in Cells: Overview
Cellular Respiration
Covers glycolysis, the Krebs cycle, and the electron transport chain at a conceptual level, aerobic vs anaerobic respiration and fermentation, and the overall equation converting glucose and oxygen into ATP, CO2, and water.
Builds on Energy in Cells: Overview
Cell Cycle and Mitosis
Covers the phases of the cell cycle (interphase, mitosis, cytokinesis), the purpose of mitosis in growth and repair, chromosome behavior during each phase, and regulation of the cell cycle including a basic look at what happens when regulation fails (cancer).
Builds on Cell Structure and Organelles
Meiosis and Sexual Reproduction
Covers the stages of meiosis I and II, how meiosis produces genetically diverse haploid gametes, crossing over and independent assortment, and comparison of mitosis vs meiosis.
Builds on Cell Cycle and Mitosis
Mendelian Genetics
Covers Gregor Mendel's pea plant experiments, dominant/recessive alleles, genotype vs phenotype, the law of segregation and independent assortment, and using Punnett squares to predict monohybrid and dihybrid cross outcomes.
Builds on Meiosis and Sexual Reproduction
Complex Patterns of Inheritance
Covers inheritance patterns beyond simple dominance: incomplete dominance, codominance, multiple alleles (e.g. blood type), polygenic traits, sex-linked inheritance, and pedigree analysis.
Builds on Mendelian Genetics
DNA Structure and Replication
Covers the discovery and double-helix structure of DNA (Watson, Crick, Franklin), base pairing rules, and the process of semi-conservative DNA replication including key enzymes (helicase, DNA polymerase).
Builds on Biological Macromolecules
Transcription and Translation
Covers the central dogma of molecular biology, how transcription creates mRNA from DNA, how translation uses mRNA and tRNA at ribosomes to build proteins via the genetic code, and the role of codons.
Builds on DNA Structure and Replication
Mutations and Gene Regulation
Covers types of mutations (point, insertion, deletion, frameshift) and their effects on proteins, plus a conceptual introduction to gene regulation (why not all genes are expressed at once) and basic concepts of biotechnology such as genetic engineering and CRISPR.
Builds on Transcription and Translation
Genetics Meets Inheritance Patterns
Connects Mendelian and molecular genetics to population-level variation, setting up how heritable variation is the raw material for evolution. Reviews how mutations and recombination create the genetic diversity evolution acts upon.
Builds on Complex Patterns of Inheritance, Mutations and Gene Regulation
Evidence for Evolution
Covers the multiple lines of evidence for evolution: fossil record, comparative anatomy (homologous/analogous structures), embryology, biogeography, and molecular/DNA evidence.
Builds on Genetics Meets Inheritance Patterns
Natural Selection and Adaptation
Covers Darwin and Wallace's theory of natural selection, the conditions required for it (variation, heritability, differential reproduction), types of selection (directional, stabilizing, disruptive), and examples such as peppered moths and antibiotic resistance.
Builds on Evidence for Evolution
Population Genetics and Speciation
Covers allele frequencies in populations, the Hardy-Weinberg principle as a null model, genetic drift, gene flow, and how reproductive isolation leads to speciation (allopatric and sympatric).
Builds on Natural Selection and Adaptation
Classification and Taxonomy
Covers the history and purpose of taxonomic classification, the hierarchy from domain to species, binomial nomenclature, and how phylogenetic trees/cladograms represent evolutionary relationships built from shared derived traits.
Builds on Evidence for Evolution
Survey of Life: Domains and Kingdoms
Covers the three domains (Bacteria, Archaea, Eukarya) and major eukaryotic kingdoms (Protista, Fungi, Plantae, Animalia), highlighting defining characteristics and evolutionary relationships among them.
Builds on Classification and Taxonomy
Population Ecology
Covers population characteristics (density, dispersion, age structure), population growth models (exponential and logistic growth), carrying capacity, and limiting factors.
Builds on Characteristics of Life
Community Ecology
Covers species interactions (competition, predation, symbiosis including mutualism/commensalism/parasitism), niches, and community-level concepts like succession and keystone species.
Builds on Population Ecology
Ecosystems: Energy Flow and Nutrient Cycles
Covers trophic levels, food chains/webs, energy pyramids and the 10% rule, and biogeochemical cycles (carbon, nitrogen, water) that recycle matter through ecosystems.
Builds on Photosynthesis, Cellular Respiration, Community Ecology
Human Impact and Conservation
Covers how human activity affects ecosystems: habitat destruction, pollution, climate change, invasive species, biodiversity loss, and conservation strategies aimed at sustainability.
Builds on Ecosystems: Energy Flow and Nutrient Cycles
Levels of Organization and Homeostasis in the Body
Covers the hierarchy of cells, tissues, organs, and organ systems, and introduces homeostasis as the shared goal of body systems, including feedback loop concepts (negative and positive feedback).
Builds on Characteristics of Life, Cell Structure and Organelles
Survey of Human Body Systems
Covers the basic structure and function of the major human organ systems (nervous, endocrine, circulatory, respiratory, digestive, excretory, immune, musculoskeletal, reproductive) at an overview level, emphasizing how they interact to maintain homeostasis.
Builds on Levels of Organization and Homeostasis in the Body
Practice questions in Biology (High School)
A few of the kinds of questions you will work through, with answers.
In an experiment testing whether fertilizer affects plant growth, what is the independent variable?
See the answer
The amount or presence of fertilizer
The independent variable is the factor the experimenter deliberately changes; plant growth is the dependent variable being measured.
What type of reaction joins two amino acids together, and what small molecule is released?
See the answer
Dehydration synthesis; water is released
Monomers like amino acids bond together by removing a water molecule, forming a peptide bond.
Why does facilitated diffusion require transport proteins but still not require ATP?
See the answer
Because it moves substances down their concentration gradient, just through a protein channel instead of directly through the lipid bilayer
Movement down a gradient is passive and energetically favorable, so no ATP is needed even though a protein assists it.
In pea plants, purple flower color (P) is dominant over white (p). What proportion of offspring from a Pp x Pp cross are expected to have white flowers?
See the answer
1/4
A Punnett square of Pp x Pp gives genotype ratio 1 PP : 2 Pp : 1 pp, and only pp (1 of 4) is white since p is recessive.
A population of beetles has mostly dark-colored individuals after a change in habitat makes dark bark more common. Which type of selection does this best illustrate?
See the answer
Directional selection
Directional selection shifts a trait distribution toward one extreme when that phenotype has a survival advantage in the changed environment.
If a producer level has 10,000 kilocalories of energy, roughly how much energy is available to the primary consumer level?
See the answer
About 1,000 kilocalories
On average only about 10 percent of energy transfers to the next trophic level, with the rest lost mostly as heat.
Questions about this subject
Do I need to have taken chemistry before this course?
No. The course introduces the chemistry concepts it needs, like atomic bonding and pH, in the Atoms, Bonds, and Water topic before building on them.
Does this cover AP Biology level material?
No. This follows a standard high school biology scope: conceptual understanding of biochemistry, cycles, and lab reasoning, not the quantitative depth or lab techniques expected in AP Biology.
How are genetics problems like Punnett squares handled in a conversation?
The tutor walks through setting up the cross with you step by step, asking you to identify alleles and fill in outcomes, rather than just showing you a worked example.
Can this be used alongside a classroom biology course?
Yes. Topics are organized in the same general order most biology courses follow, so you can use it to review a unit before a test or go back over something that did not make sense in class.
Ready to learn Biology (High School)?
Free to start. The tutor meets you where you are.
Start learning Biology (High School)