The Full Guide
FITE Notes: Biology
Everything you need to pass high-school biology and stay eligible.
From Coach Fite
Listen. You don't have to love biology. You have to pass it. No grades, no eligibility, no field. I went hungry for the chance to play, so don't give yours away over a class you could've passed with twenty minutes a night. Read these notes, lock in the key terms, and go get your grade like you go get a first down.
Lesson 1: The Characteristics of Life and the Scientific Method
Biology is the study of living things. Before you can study life, you have to be able to tell what is alive. Scientists agree on a short list of traits that every living thing shares.
- ●Made of one or more cells
- ●Uses energy and has a metabolism
- ●Grows and develops
- ●Reproduces (makes more of its kind)
- ●Responds to its environment (stimuli)
- ●Maintains homeostasis (a stable inside)
- ●Has DNA and can evolve as a group over time
KEY TERM
Homeostasis is how an organism keeps its inside conditions steady, like your body holding a temperature near 98.6 degrees Fahrenheit even when it is hot out.
The Scientific Method
This is the step-by-step way scientists answer questions. Learn the order.
- 1Observe and ask a question
- 2Form a hypothesis (a testable, if-then prediction)
- 3Design and run an experiment
- 4Collect and analyze data
- 5Draw a conclusion and share results
ON THE TEST
In an experiment, the independent variable is what you change, the dependent variable is what you measure, and the control group is the untreated group you compare against. Change only one variable at a time.
Lesson 2: Cells, Organelles, and the Cell Membrane
The cell is the basic unit of life. Cell theory says all living things are made of cells, the cell is the smallest unit of life, and all cells come from other cells.
Prokaryotic vs Eukaryotic
- ●Prokaryotic: small, simple, no nucleus, DNA floats free. Bacteria are prokaryotes.
- ●Eukaryotic: bigger, has a nucleus and membrane-bound organelles. Plants, animals, fungi, and protists are eukaryotes.
Main Organelles and Their Jobs
- ●Nucleus: control center, holds the DNA
- ●Mitochondria: powerhouse, makes energy (ATP) through cellular respiration
- ●Ribosomes: build proteins
- ●Endoplasmic reticulum: transport system that moves materials
- ●Golgi apparatus: packages and ships proteins
- ●Chloroplasts: do photosynthesis (plant cells only)
- ●Vacuole: storage, large in plant cells
- ●Cell wall: stiff outer layer for support (plants, fungi, bacteria, not animals)
KEY TERM
The cell membrane is a flexible barrier around every cell. It is selectively permeable, meaning it controls what enters and leaves. This keeps the right things in and the wrong things out.
Lesson 3: Cellular Energy, Photosynthesis and Respiration
Living things run on energy. Plants capture energy from the sun, and almost all living things release that stored energy to power their cells. The energy currency of the cell is called ATP.
Photosynthesis
Photosynthesis happens in the chloroplasts of plants. It takes in light energy and turns it into stored sugar.
REMEMBER
Photosynthesis: carbon dioxide plus water plus light energy gives glucose (sugar) plus oxygen.
Cellular Respiration
Cellular respiration happens in the mitochondria of nearly all cells. It breaks down sugar to release usable energy.
REMEMBER
Cellular respiration: glucose plus oxygen gives carbon dioxide plus water plus energy (ATP).
Notice that these two are opposites. The products of one are the reactants of the other. That cycle keeps oxygen and carbon dioxide balanced on Earth.
Coach Fite
That mitochondria is the engine room, the power plant. No fuel, no motor running, no fourth quarter. Feed your body right and your engine keeps firing when the other guy is gassed.
Lesson 4: DNA, RNA, and Protein Synthesis
DNA is the instruction manual for building and running an organism. It is passed from parents to offspring.
Structure of DNA
- ●DNA is shaped like a twisted ladder called a double helix
- ●The rungs are made of paired bases: A, T, C, and G
- ●Base pairing rule: A pairs with T, and C pairs with G
- ●A gene is a section of DNA that codes for one protein
KEY TERM
RNA is a single-strand helper molecule that carries DNA instructions out of the nucleus to the ribosome. In RNA, the base uracil (U) takes the place of thymine (T).
Making a Protein (Two Steps)
- 1Transcription: DNA is copied into messenger RNA inside the nucleus
- 2Translation: the ribosome reads the RNA in three-letter codons and links amino acids into a protein
ON THE TEST
Remember the flow of information: DNA to RNA to protein. Proteins do most of the work in your body, from building muscle to speeding up reactions.
Lesson 5: Genetics and Heredity
Heredity is how traits pass from parents to offspring. Gregor Mendel, a monk who bred pea plants, figured out the basic rules and is called the father of genetics.
The Vocabulary You Must Know
- ●Allele: a version of a gene (you get one from each parent)
- ●Dominant: an allele that shows up even if only one copy is present (written as a capital letter)
- ●Recessive: an allele that only shows when both copies are present (written as a lowercase letter)
- ●Genotype: the actual alleles you carry, like Bb
- ●Phenotype: the trait you can see, like brown eyes
- ●Homozygous: two matching alleles (BB or bb)
- ●Heterozygous: two different alleles (Bb)
Punnett Squares
A Punnett square is a box that predicts the chance of offspring traits. You put one parent's alleles across the top and the other parent's down the side, then fill in the combinations.
ON THE TEST
Crossing two heterozygous parents (Bb times Bb) gives a 3 to 1 ratio: three offspring show the dominant trait for every one that shows the recessive trait.
Lesson 6: Evolution and Natural Selection
Evolution is the change in the inherited traits of a population over many generations. Charles Darwin explained how it happens through natural selection.
How Natural Selection Works
- 1Variation: individuals in a population are slightly different
- 2Some traits help an individual survive and reproduce in its environment
- 3Those individuals pass their helpful traits to more offspring
- 4Over time, the helpful traits become more common in the population
KEY TERM
Survival of the fittest does not mean the strongest or biggest. Fitness means how well an organism survives and reproduces in its environment. The best-fit traits get passed on.
Evidence for Evolution
- ●Fossils that show how species changed over time
- ●Similar body structures in related species (homologous structures)
- ●Shared DNA and proteins between species
- ●Observed changes today, like bacteria becoming resistant to antibiotics
REMEMBER
Natural selection acts on whole populations over time, not on a single individual changing during its own life.
Lesson 7: Ecology and Earth's Cycles
Ecology is the study of how living things interact with each other and their environment. An ecosystem is all the living and nonliving things in an area working together.
Energy Flow
- ●Producers (plants) make their own food from sunlight
- ●Consumers eat other organisms (herbivores, carnivores, omnivores)
- ●Decomposers (bacteria and fungi) break down dead matter and recycle nutrients
- ●A food chain shows one path of energy; a food web shows many connected chains
KEY TERM
In an energy pyramid, only about 10 percent of the energy passes to the next level. That is why there are many plants, fewer plant-eaters, and even fewer top predators.
The Carbon and Water Cycles
- ●Carbon cycle: carbon moves through photosynthesis, respiration, decay, and the burning of fuels
- ●Water cycle: water moves by evaporation, condensation, precipitation, and collection
ON THE TEST
Energy flows one way through an ecosystem and is lost as heat. Matter like carbon and water is recycled again and again.
Lesson 8: Human Body Systems
Your body is made of organ systems that each do a job and work together to keep you alive. Here is the quick tour.
- ●Skeletal: bones that support the body and protect organs
- ●Muscular: muscles that move the body and pump the heart
- ●Circulatory: heart and blood vessels that carry oxygen and nutrients
- ●Respiratory: lungs that take in oxygen and remove carbon dioxide
- ●Digestive: breaks down food into nutrients your cells can use
- ●Nervous: brain, spinal cord, and nerves that send signals and control the body
- ●Endocrine: glands that release hormones to regulate the body
- ●Excretory: kidneys that filter waste out of the blood
- ●Immune: defends the body against germs and disease
- ●Reproductive: makes offspring
REMEMBER
No system works alone. For example, the respiratory system grabs oxygen and the circulatory system delivers it, so your muscles can keep working.
ON THE TEST
Be ready to match a system to its main job and to name one organ in it. That is the most common body-systems question.