| Feature | Prokaryote | Eukaryote |
|---|---|---|
| Nucleus | ❌ None | ✅ Yes |
| Size | Smaller | Larger |
| DNA | Circular (nucleoid) | Linear in nucleus |
| Examples | Bacteria | Plants, Animals |
| Age | Older | Newer |
| Feature | Plant | Animal |
|---|---|---|
| Cell Wall | ✅ | ❌ |
| Chloroplasts | ✅ | ❌ |
| Large Vacuole | ✅ | ❌ |
| Centrioles | ❌ | ✅ |
| Organelle | Function |
|---|---|
| Nucleus | Contains DNA — control center |
| Nucleolus | Makes ribosomes |
| Ribosome | Makes proteins |
| Mitochondria | Makes ATP — powerhouse |
| Rough ER | Assembles & transports proteins |
| Smooth ER | Makes enzymes, calcium |
| Golgi | Packages & ships proteins |
| Lysosome | Digests old cell parts |
| Vacuole | Stores water & nutrients |
| Cell Membrane | Controls entry/exit |
| Centrioles | Help with cell division (animals only) |
Movement of molecules from HIGH to LOW concentration — down the gradient. Requires NO energy (ATP) — passive transport.
| Type | How | Energy? |
|---|---|---|
| Simple | Small molecules cross directly | None |
| Facilitated | Uses protein channels for large molecules | None |
Diffusion of WATER ONLY through a selectively permeable membrane. Water moves toward more solute. No ATP needed.
| Solution | Water Moves | Animal Cell | Plant Cell |
|---|---|---|---|
| Hypotonic | INTO cell | Swells/bursts | Turgid ✅ |
| Hypertonic | OUT of cell | Shrinks | Plasmolysis |
| Isotonic | Both ways equally | Normal | Normal |
The ability to maintain a stable internal environment despite external changes. Body constantly adjusts temperature, blood sugar, pH, and water balance.
| Phase | What Happens |
|---|---|
| G1 | Cell grows, normal functions |
| S Phase | DNA replicated (copied) |
| G2 | Grows more, prepares to divide |
| M Phase | Mitosis + Cytokinesis |
| Phase | Key Events | Hook |
|---|---|---|
| Prophase | Chromosomes condense, spindle forms, nuclear envelope breaks down | Prepare |
| Metaphase | Chromosomes line up at the MIDDLE equator | Middle |
| Anaphase | Sister chromatids pulled APART to poles | Apart |
| Telophase | Nuclear envelopes reform, chromosomes decondense | Two nuclei |
| Cytokinesis | Cytoplasm splits → 2 identical daughter cells | Done! |
| Feature | Mitosis | Meiosis |
|---|---|---|
| Purpose | Growth & repair | Sex cells |
| Cells produced | 2 identical diploid | 4 unique haploid |
| Crossing over? | No | Yes |
| Checkpoint | What It Checks | When |
|---|---|---|
| G1 Checkpoint | Is DNA damaged? Is the cell big enough? | Before S phase |
| G2 Checkpoint | Was DNA replicated properly? | Before mitosis |
| M (Spindle Assembly) Checkpoint | Are all chromosomes aligned at equator? | During metaphase |
| Phase | Key Events | Hook |
|---|---|---|
| Prophase | Chromosomes condense. Spindle fibers form. Nuclear envelope breaks down. Spindle fibers ATTACH to chromatids. | Prepare |
| Metaphase | All chromosomes LINE UP at the cell's equator (metaphase plate) | Middle |
| Anaphase | Sister chromatids PULLED to opposite poles. Chromosomes are at opposite poles. | Apart |
| Telophase | Spindle fibers disappear. Nuclear envelopes reform. Chromosomes decondense. New nucleus forms. | Two nuclei |
| Cytokinesis | Cytoplasm divides. Completes cell division. Two daughter cells formed. | Cut |
| Feature | Asexual | Sexual |
|---|---|---|
| Parents needed | ONE | TWO |
| Offspring genetics | Identical (clones) | Unique (genetically different) |
| Speed | Faster | Slower |
| Adaptation | Poor (no diversity) | Good (diversity helps adapt) |
| Who uses it | Most single-celled organisms | Most multicellular organisms |
| Involves | Mitosis | Meiosis — union of sex cells (egg & sperm) |
| Example | Budding, binary fission | Humans, most animals |
| Factor | Effect on Rate |
|---|---|
| Greater distance to travel | SLOWER diffusion rate |
| Dense solvents | DECREASE the rate |
| Molecule size (small nonpolar) | Pass through membrane EASIER |
| Higher concentration | INCREASE diffusion rate |
| Higher temperature | FASTER diffusion |
| Energy requirement | Does NOT require energy (passive) |
Remember: compare solute concentration OUTSIDE vs INSIDE the cell.
| Solution Type | Solute Outside vs Inside | Water Moves | Cell Result |
|---|---|---|---|
| Hypertonic | MORE solute outside | OUT of cell | Cell shrinks/crenates |
| Hypotonic | LESS solute outside | INTO cell | Cell swells/bursts |
| Isotonic | EQUAL solute both sides | Both ways equally | No change |
| Increases Temp 🔺 | Decreases Temp 🔻 |
|---|---|
| Shivering (muscle contractions → heat) | Sweating |
| Exercising | Standing in a pool |
| Raising air temperature | Lowering air temperature |
| Adding clothing | Removing clothing |
| Checkpoint | What It Checks | When |
|---|---|---|
| G1 Checkpoint | Is DNA damaged? Is the cell big enough? | Before DNA replication |
| G2 Checkpoint | Was DNA replicated properly? | Before mitosis begins |
| M Checkpoint (Spindle Assembly) | Are all chromosomes aligned at equator? | During metaphase |
| Factor | Effect on Diffusion Rate |
|---|---|
| Greater distance | SLOWER — more ground to cover |
| Dense solvent | DECREASES rate — harder to move through |
| Molecule size | Small NONPOLAR molecules cross easiest |
| Higher concentration | INCREASES rate — steeper gradient |
| Higher temperature | FASTER — more kinetic energy |
| Energy needed? | NO — diffusion is passive |
| Scenario | Solution Type | Water Moves |
|---|---|---|
| Cell: 40% water 60% solute | Solution: 60% water 40% solute | HYPOTONIC (less solute outside) | INTO cell — cell swells |
| Cell: 60% water 40% solute | Solution: 60% water 40% solute | ISOTONIC (equal solutes) | Both ways equally |
| Cell: 60% water 40% solute | Solution: 40% water 60% solute | HYPERTONIC (more solute outside) | OUT of cell — cell shrinks |
| Phase | Key Events | Tip |
|---|---|---|
| Prophase | Chromosomes condense, nuclear envelope breaks down, spindle fibers attach to chromatids | Prepare |
| Metaphase | ALL chromosomes line up at the cell's equator | Middle — easiest to count chromosomes! |
| Anaphase | Sister chromatids pulled to OPPOSITE POLES | Apart |
| Telophase | Chromosomes at opposite poles, spindle fibers disappear, nuclear envelopes reform | Two nuclei forming |
| Cytokinesis | Cytoplasm splits into two daughter cells, completes division | Done! |
| Feature | Asexual | Sexual |
|---|---|---|
| Parents needed | 1 | 2 |
| Offspring | Genetically IDENTICAL | Genetically DIFFERENT |
| Speed | Faster | Slower |
| Adaptation? | No — no genetic diversity | Yes — genetic variation helps adaptation |
| Who does it? | Most single-celled organisms | Most multicellular organisms |
| Example | Budding, binary fission | Union of egg & sperm |
| Term | Definition | Tip |
|---|---|---|
| Radius (r) | Distance from center to edge | Half the diameter |
| Diameter (d) | Distance all the way across | d = 2r |
| Pi (π) | ≈ 3.14 (or 22/7) | Never-ending number |
| Circumference | Distance around the circle | Like the perimeter |
| Area | Space inside the circle | Measured in units² |
A circle has a diameter of 10 cm. Find the circumference.
A circle has a radius of 5 cm. Find the area.
If you're given the diameter but need radius: divide by 2
In this future society, everyone is considered "ugly" until they turn 16. At 16, everyone gets a surgery to become "pretty" — perfectly beautiful by society's standards. The story follows Tally Youngblood as she questions whether beauty and conformity are worth the cost.
| Part | What Happens |
|---|---|
| Beginning | Tally is an Ugly, 3 months from surgery. Her friend Peris already turned Pretty. She sneaks into New Pretty Town. |
| Rising Action | Tally meets Shay, who doesn't want the surgery. Shay runs away to "the Smoke" — a hidden rebel settlement. |
| Conflict | Dr. Cable blackmails Tally — find the Smoke or never become Pretty. Tally agrees and follows Shay's coded directions. |
| Climax | Tally arrives at the Smoke, discovers the surgery also brain-damages people. She accidentally triggers a tracker. |
| Resolution | Special Circumstances raids the Smoke. To save David's parents, Tally turns herself in to get the surgery. |
| Device | Definition | Example from Uglies |
|---|---|---|
| Dystopia | A seemingly perfect society with dark underlying control | Everyone becomes "pretty" but loses free thought |
| Symbolism | Objects/ideas representing something deeper | Surgery = conformity and loss of identity |
| Foreshadowing | Hints at future events | Shay's resistance hints at the rebellion to come |
| Irony | Opposite of what's expected | "Pretty" surgery makes people ugly on the inside |
| Conflict | Internal and external struggle | Tally torn between fitting in and doing what's right |
The Cold War was a period of political tension between the United States and the Soviet Union (USSR) from roughly 1947 to 1991. It was called "cold" because the two superpowers never directly fought each other — instead they competed through proxy wars, arms races, and propaganda.
| Cause | Explanation |
|---|---|
| Ideological Differences | USA (democracy/capitalism) vs USSR (communism) — totally opposite systems |
| Post-WWII Power Vacuum | After WW2, USA and USSR emerged as the two superpowers |
| Soviet Expansion | USSR took control of Eastern European countries after WW2 |
| Atomic Bomb | USA had nuclear weapons first — USSR feared this and raced to catch up |
| Year | Event | Why It Matters |
|---|---|---|
| 1947 | Truman Doctrine | USA pledges to stop the spread of communism |
| 1949 | USSR gets atomic bomb | Now both sides have nukes — arms race begins |
| 1950–53 | Korean War | USA vs communist North Korea — first proxy war |
| 1957 | Sputnik launched | USSR first in space — space race begins |
| 1961 | Berlin Wall built | Divides communist East and democratic West Berlin |
| 1962 | Cuban Missile Crisis | Closest the world came to nuclear war |
| 1969 | Moon Landing | USA wins the space race |
| 1989 | Berlin Wall falls | Symbol of Cold War ending |
| 1991 | USSR dissolves | Cold War officially ends — USA wins |
| Term | Definition |
|---|---|
| Containment | US policy to stop communism from spreading to new countries |
| Arms Race | USA & USSR competing to build more/better nuclear weapons |
| Proxy War | Two superpowers support opposite sides in another country's war |
| Iron Curtain | Imaginary line dividing communist Eastern Europe from the West |
| MAD | Mutually Assured Destruction — both sides would be destroyed in nuclear war |
| Space Race | USA vs USSR competing to achieve space milestones first |
| NATO | US-led military alliance of Western democratic nations |
| Warsaw Pact | Soviet-led military alliance of communist nations |
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