Biology Final STUDY GUIDE

🔬 Introduction to Biology

Characteristics of Life: Order, reproduction, growth & development, metabolism, homeostasis, response to stimuli, evolutionary adaptation

Scientific Method:

Observation → Question → Hypothesis → Experiment → Data → Conclusion

Quantitative data = numbers; Qualitative data = descriptions

Hypothesis = testable explanation

Experimental group = receives treatment

Control group = no treatment (baseline)

Independent variable = changed

Dependent variable = measured

Constants = kept the same

🌍 Ecology

Biotic = living things | Abiotic = non-living factors (e.g., temperature, water)

Symbiosis:

Mutualism: both benefit (bee & flower)

Parasitism: one benefits, one harmed (tapeworm)

Commensalism: one benefits, other unaffected (barnacle on whale)

Competition = organisms fight for the same resources

Predation = predator eats prey

Herbivory = animal eats plants

Producers (autotrophs): make their own food (plants)

Consumers (heterotrophs): eat others for energy

Herbivore: eats plants

Carnivore: eats meat

Omnivore: eats both

Decomposers: break down dead matter (fungi, bacteria)

Food Web: interconnected food chains

Energy Flow: 10% of energy passes to next level

Matter Cycles: carbon, nitrogen, water cycles

Invasive species: non-native, disrupt ecosystems

Exponential vs. Logistic Growth:

Exponential = J curve (unlimited)

Logistic = S curve (limited by carrying capacity)

⚗ Biochemistry

Organic molecules = contain carbon

Monomer = building block | Polymer = chain of monomers

Carbohydrates:

Monosaccharides = sugars (glucose)

Polysaccharides = starch, cellulose

Lipids: fats & oils

Types: Triglycerides, phospholipids, steroids

Hydrophobic = repels water | Hydrophilic = attracts water

Proteins:

Amino acids = monomers

Polypeptide = chain of amino acids

Enzymes = speed up reactions

Active site binds substrate

Denaturation = loss of function (heat/pH)

Nucleic acids:

DNA & RNA

Monomer: nucleotide (sugar + phosphate + base)

🧫 Cells and Cell Transport

Prokaryotic = no nucleus (bacteria) | Eukaryotic = nucleus

Animal vs. Plant Cells:

Plant: cell wall, chloroplast, large vacuole

Animal: lysosome, small vacuoles

Organelles & Functions:

Nucleus: controls cell

Plasma membrane: regulates entry/exit

Cell wall: support (plants only)

Cytoplasm: jelly-like fluid

Ribosomes: make proteins

ER (rough): protein transport; (smooth): lipid production

Vacuoles: storage

Mitochondria: powerhouse (ATP production)

Chloroplast: photosynthesis (plants only)

Golgi apparatus: packages proteins

Lysosome: digests waste

Transport:

Passive = no energy (diffusion, osmosis)

Active = uses energy

Diffusion: particles move from high to low concentration

Osmosis: water diffusion

Equilibrium: balanced concentration

⚡ Cellular Respiration & Photosynthesis

Cellular Respiration:

Purpose: Make ATP from glucose

Occurs in: Mitochondria

Steps: Glycolysis, Krebs Cycle, ETC

Anaerobic (no O₂): fermentation (lactic acid/alcohol)

Aerobic: uses oxygen

Photosynthesis:

Equation: CO₂ + H₂O + sunlight → O₂ + glucose

Happens in chloroplast

Light reactions: use sunlight, make ATP

Calvin Cycle: uses CO₂ to make sugar

🔁 Cell Division

Asexual (1 parent, clone) vs. Sexual (2 parents, variation)

Mitosis: somatic cell division (growth, repair)

PMAT: Prophase, Metaphase, Anaphase, Telophase

Meiosis: makes gametes (sperm/egg)

Crossing over = variation

Ends in 4 unique haploid cells

Somatic cells = body cells | Gametes = sex cells

Chromosome: DNA + protein

Chromatin = loose DNA | Chromatids = copied chromosomes

Homologous chromosomes: same genes, different versions

Autosomes = non-sex chromosomes | Sex chromosomes = X, Y

Fertilization = sperm + egg → Zygote

Haploid = 1 set of chromosomes | Diploid = 2 sets

Cancer: uncontrolled cell division

🧬 Genetics

Genotype: genetic makeup | Phenotype: physical trait

Allele: gene variant

Dominant vs. Recessive

Homozygous = same alleles | Heterozygous = different alleles

Punnett Square: predicts traits

Incomplete dominance: blended (red + white = pink)

Codominance: both show (AB blood)

Multiple alleles: more than two options (A, B, O)

Sex-linked: traits on X chromosome

Pedigree: family trait chart

🧬 DNA & Protein Synthesis

DNA: double helix, made of nucleotides (A-T, C-G)

Replication:

Helicase: unzips DNA

DNA polymerase: adds new bases

Ligase: seals fragments

Transcription: DNA → mRNA (in nucleus)

Translation: mRNA → protein (in ribosome)

tRNA carries amino acids

Codon = 3-base mRNA code for 1 amino acid

Peptide bond = joins amino acids

Mutation: change in DNA

🌱 Evolution

Darwin: natural selection

Fitness = survival + reproduction

Evidence:

Homologous structures = same structure, different function

Fossil record

Genetic & embryo similarities

Speciation = formation of new species

Adaptations = traits that help survival

🧍‍♂ Human Body Systems

Homeostasis: maintaining balance

Digestive:

Mouth → stomach → small intestine → large intestine

Chemical digestion (enzymes) vs. Mechanical digestion (chewing)

Cardiovascular:

Heart, arteries (away), veins (to heart), capillaries

Pulmonary = lungs; Systemic = rest of body

Respiratory:

Lungs, bronchi, bronchioles, alveoli

Gas exchange via diffusion

Reproductive:

Male: testes, sperm

Female: ovaries, egg, uterus

Fertilization → implantation in uterus

Processes

🔬 INTRODUCTION TO BIOLOGY

Characteristics of Life:

Order: Organized structure (cells > tissues > organs > systems)

Reproduction: Asexual or sexual reproduction to pass on genes

Growth & Development: Controlled by DNA instructions

Metabolism: All chemical reactions for energy conversion

Homeostasis: Maintaining internal balance (e.g., temperature)

Response to Stimuli: Reacting to environment (e.g., pulling hand from hot stove)

Evolutionary Adaptation: Traits that help organisms survive over generations

Scientific Method:

Ask a Question

Form a Hypothesis

Conduct an Experiment

Collect Data (Qualitative = descriptive; Quantitative = numerical)

Analyze Results

Draw a Conclusion

Repeat/Revise

Experimental Design Terms:

Control group: No change, baseline

Experimental group: Receives treatment

Independent variable: What is changed

Dependent variable: What is measured

Constants: Variables kept the same

🌍 ECOLOGY

Biotic vs. Abiotic:

Biotic: Living factors (plants, animals, bacteria)

Abiotic: Non-living (water, light, temperature)

Symbiosis Types:

Mutualism: Both benefit (bee and flower)

Parasitism: One benefits, one harmed (tapeworm)

Commensalism: One benefits, other unaffected (barnacle on whale)

Other Interactions:

Competition: Limited resources

Predation: One organism eats another

Herbivory: Animal eats plants

Trophic Roles:

Producers (Autotrophs): Use photosynthesis to make food

Consumers (Heterotrophs): Eat others for energy

Herbivores eat plants

Carnivores eat animals

Omnivores eat both

Decomposers: Break down dead matter

Energy Flow:

Energy decreases ~90% per level (heat loss)

Arrows in food webs point in the direction of energy flow

Matter Cycling:

Water Cycle: Evaporation → Condensation → Precipitation → Runoff/Infiltration

Carbon Cycle: Photosynthesis ↔ Respiration, combustion adds CO2

Nitrogen Cycle: Nitrogen fixation → Assimilation → Ammonification → Nitrification → Denitrification

Growth Patterns:

Exponential Growth: J-curve, unlimited resources

Logistic Growth: S-curve, limited by carrying capacity

Invasive Species:

Non-native, disrupt ecosystem balance

⚛ BIOCHEMISTRY

Organic Molecules: Contain carbon

Monomer: Small unit

Polymer: Chain of monomers

Carbohydrates:

Monomer: Monosaccharides (glucose)

Polymer: Polysaccharides (starch, cellulose)

Function: Quick energy

Lipids:

Types: Triglycerides, Phospholipids, Steroids

Function: Long-term energy, cell membranes

Hydrophobic (repel water)

Proteins:

Monomer: Amino acids

Polymer: Polypeptides

Function: Structure, enzymes

Enzymes:

Lower activation energy

Active Site binds substrate

Denaturation: Loses shape due to pH/temp

Nucleic Acids:

Monomer: Nucleotide (sugar + phosphate + base)

Types: DNA & RNA

🧰 CELLS AND TRANSPORT

Cell Types:

Prokaryotes: No nucleus (bacteria)

Eukaryotes: Have nucleus (plants/animals)

Organelles:

Nucleus: Stores DNA

Cell Wall: Support (plants)

Plasma Membrane: Regulates entry/exit

Cytoplasm: Fluid inside cell

Ribosomes: Make proteins

ER (Rough): Has ribosomes, protein processing

ER (Smooth): Makes lipids

Vacuole: Storage

Chloroplast: Photosynthesis

Mitochondria: Cell respiration

Golgi Apparatus: Packages materials

Lysosomes: Digestion

Transport:

Passive Transport (no energy):

Diffusion: High → Low

Osmosis: Water diffusion

Facilitated diffusion: Uses protein channels

Active Transport (uses energy): Low → High

Equilibrium: Balanced concentration

⚡️ CELLULAR RESPIRATION & PHOTOSYNTHESIS

Cellular Respiration (in mitochondria):

Purpose: Make ATP from glucose

Equation: C6H12O6 + O2 → CO2 + H2O + ATP

Steps:

Glycolysis: Glucose → Pyruvate (in cytoplasm)

Krebs Cycle: Pyruvate → CO2 + NADH + FADH2

ETC: Uses NADH/FADH2 → ATP + H2O

Anaerobic: No O2 → Lactic acid or alcohol fermentation

Photosynthesis (in chloroplast):

Equation: CO2 + H2O + light → C6H12O6 + O2

Light Reactions: Use light, produce ATP/NADPH

Calvin Cycle: Use CO2 to make glucose

📆 CELL DIVISION

Mitosis (Body Cells):

Purpose: Growth, repair, replace

Stages (PMAT):

Prophase: Chromosomes condense

Metaphase: Line up at middle

Anaphase: Sister chromatids pulled apart

Telophase: Nuclear membranes form

Cytokinesis: Cell splits

Meiosis (Sex Cells):

Purpose: Make gametes

2 divisions → 4 unique haploid cells

Crossing Over: In Prophase I, adds variation

Fertilization: Egg + sperm → Zygote

Diploid (2n): Full set | Haploid (n): Half set

🦉 GENETICS

Key Terms:

Gene: DNA segment for a trait

Allele: Version of gene

Genotype: Genetic makeup

Phenotype: Physical trait

Dominant/Recessive: Dominant shows if present

Homozygous: Same alleles | Heterozygous: Different

Patterns of Inheritance:

Incomplete Dominance: Blending (red + white = pink)

Codominance: Both alleles show (AB blood)

Multiple Alleles: More than 2 options (A, B, O)

Sex-linked Traits: On X chromosome

Pedigrees: Family trees to track traits

🔎 DNA & PROTEIN SYNTHESIS

DNA Structure:

Double helix; A-T, C-G pairing

Nucleotide: Sugar + phosphate + base

DNA Replication:

Helicase: Unzips

DNA Polymerase: Adds bases

Ligase: Seals fragments

Protein Synthesis:

Transcription (Nucleus):

DNA → mRNA

Enzyme: RNA Polymerase

Translation (Ribosome):

mRNA → Protein

tRNA matches codon to amino acid

Codon: 3-letter mRNA sequence = 1 amino acid

Linked by peptide bonds

Mutations:

Change in DNA; may affect protein

🧬 HUMAN BODY SYSTEMS

Homeostasis:

Regulates internal conditions (e.g., temp, pH)

Digestive System:

Mouth: Mechanical + chemical (amylase)

Stomach: Acid and enzymes (pepsin)

Small Intestine: Nutrient absorption

Large Intestine: Water absorption

Cardiovascular System:

Heart: Pumps blood

Veins: To heart

Arteries: Away from heart

Capillaries: Gas exchange

Pulmonary Circuit: Heart ↔ lungs

Systemic Circuit: Heart ↔ body

Respiratory System:

Lungs, bronchi, bronchioles, alveoli

Gas exchange: O2 in, CO2 out via diffusion

Reproductive System:

Male: Testes (sperm)

Female: Ovaries (eggs), uterus

Fertilization: Egg + sperm

Implantation: In uterine lining