Biology
Evolution and ecology
Natural selection, phylogeny, trophic levels, cycles.
Basics
Natural selection
If variation is heritable and survival or reproduction differs, trait frequencies change. Adaptation is fitness in a given environment.
Phylogeny
A branching history from common ancestors. Homology (shared ancestry) is not analogy (convergence). Binomial names: genus + species.
Trophic levels
Producers → primary consumers → higher consumers. A rough 10% of energy often reaches the next level. Matter cycles; energy flows.
Formulas
Exponential growth
Unlimited population growth. Real populations meet a carrying capacity K.
Symbols
-
Npopulation size -
rintrinsic growth rate
Logistic growth
Growth stops as N approaches K. An S-shaped curve.
Symbols
-
Kcarrying capacity
Key table
| Three domains | Bacteria, Archaea, Eukarya |
|---|---|
| Carbon | Fixed by photosynthesis; returned as CO₂ by respiration and burning |
| Nitrogen | Nitrogen-fixing microbes convert N₂ to ammonium |
In this field
The cell
Prokaryotes vs eukaryotes, organelles, membranes.
Genetics and molecular biology
DNA, transcription/translation, Mendel, meiosis.
Metabolism
Photosynthesis, respiration, ATP, enzymes.
Human physiology basics
Homeostasis, circulation, nerves, immunity.
Plants and development
Plant tissues, hormones, developmental stages.
Immunity and microbes
Pathogens, innate and adaptive immunity, antibiotics and vaccines.
Nervous and endocrine systems
Neurons, synapses, hormones, and homeostasis — fast electrical and slower chemical signals.
Molecular lab sketch
Restriction enzymes, electrophoresis, PCR, and sequencing — a short principle sketch.
Population ecology
Exponential and logistic growth, carrying capacity, life history, predator–prey sketch.
Life’s diversity
Domains, a phylogeny sketch, homology versus analogy, and binomial names.
Biological macromolecules
Carbohydrates, lipids, proteins, and nucleic acids — structure and role sketches.