Science
Living Things, Human Body Systems, Earth & Space, Matter & Energy
Table of Contents
1. Living Things
Characteristics of Living Things
Remember: MRS GREN
M
Movement
R
Respiration
S
Sensitivity
G
Growth
R
Reproduction
E
Excretion
N
Nutrition
Plant Parts and Functions
| Part | Function |
|---|---|
| Roots | Absorb water and nutrients, anchor plant |
| Stem | Transport water and nutrients, support |
| Leaves | Photosynthesis (make food), gas exchange |
| Flower | Reproduction |
| Fruit | Protect seeds, help dispersal |
Photosynthesis
Carbon Dioxide + Water + Sunlight → Glucose + Oxygen
CO₂ + H₂O + Light Energy → C₆H₁₂O₆ + O₂
Takes place in chloroplasts (contains chlorophyll - green pigment)
Animal Classification
Vertebrates (with backbone)
- • Fish - gills, scales, cold-blooded
- • Amphibians - moist skin, cold-blooded
- • Reptiles - dry scales, cold-blooded
- • Birds - feathers, warm-blooded
- • Mammals - hair/fur, warm-blooded, milk
Invertebrates (no backbone)
- • Insects - 6 legs, 3 body parts
- • Arachnids - 8 legs (spiders)
- • Mollusks - soft body (snails, octopus)
- • Worms - segmented body
- • Jellyfish - no bones at all
2. Human Body Systems
Circulatory System
Function: Transport blood, nutrients, and oxygen
- • Heart - pumps blood (4 chambers)
- • Arteries - carry blood AWAY from heart (oxygenated)
- • Veins - carry blood TO heart (deoxygenated)
- • Capillaries - tiny vessels for exchange
Respiratory System
Function: Breathing - take in oxygen, release carbon dioxide
- • Nose/Mouth - air entry
- • Trachea (windpipe) - air passage
- • Bronchi - branches to lungs
- • Lungs - gas exchange in alveoli
- • Diaphragm - muscle for breathing
Digestive System
Function: Break down food, absorb nutrients
Mouth → Esophagus → Stomach → Small Intestine → Large Intestine → Rectum
- • Mouth - mechanical digestion (teeth), chemical (saliva)
- • Stomach - acid breaks down food
- • Small intestine - nutrient absorption
- • Large intestine - water absorption
Nervous System
Function: Control and coordinate body activities
- • Brain - control center (thinking, memory)
- • Spinal cord - message highway
- • Nerves - carry signals throughout body
Skeletal & Muscular Systems
Skeletal (206 bones)
- • Support and shape
- • Protect organs
- • Produce blood cells
Muscular (600+ muscles)
- • Movement
- • Maintain posture
- • Generate heat
3. Earth's Structure
Layers of the Earth
Crust
Outermost layer, 5-70 km thick. We live here!
Mantle
Thick layer of hot rock, ~2,900 km. Convection currents move plates.
Outer Core
Liquid iron and nickel, ~2,200 km. Creates magnetic field.
Inner Core
Solid iron and nickel, ~1,200 km. Hottest part (~5,500°C).
Types of Rocks
Igneous
From cooled magma/lava
Examples: granite, basalt
Sedimentary
From compressed sediments
Examples: limestone, sandstone
Metamorphic
Changed by heat/pressure
Examples: marble, slate
Natural Disasters
Earthquake
Sudden shaking from movement of tectonic plates. Measured by Richter scale.
Volcanic Eruption
Release of magma, ash, and gases from volcano.
Typhoon
Tropical cyclone with strong winds and rain. Forms over warm ocean water.
Flood
Overflow of water onto normally dry land. Often caused by heavy rain.
4. Solar System
Remember the Planets
"My Very Eager Mother Just Served Us Nachos"
The 8 Planets (from Sun)
| Planet | Type | Key Facts |
|---|---|---|
| Mercury | Rocky | Smallest, closest to Sun |
| Venus | Rocky | Hottest planet, spins backward |
| Earth | Rocky | Only planet with life, has water |
| Mars | Rocky | Red planet, has 2 moons |
| Jupiter | Gas Giant | Largest planet, Great Red Spot |
| Saturn | Gas Giant | Famous for its rings |
| Uranus | Ice Giant | Tilted on its side |
| Neptune | Ice Giant | Farthest, strongest winds |
Earth's Movements
Rotation
Earth spinning on its axis
Takes: 24 hours (1 day)
Causes: Day and Night
Revolution
Earth orbiting around the Sun
Takes: 365.25 days (1 year)
Causes: Seasons
Phases of the Moon
Full cycle takes about 29.5 days
5. Matter and Its Properties
What is Matter?
Anything that has mass and takes up space (volume).
States of Matter
Solid
- • Fixed shape
- • Fixed volume
- • Particles packed tight
- • Example: Ice, wood
Liquid
- • No fixed shape
- • Fixed volume
- • Particles loosely packed
- • Example: Water, juice
Gas
- • No fixed shape
- • No fixed volume
- • Particles spread out
- • Example: Air, steam
Changes of State
Melting
Solid → Liquid
Freezing
Liquid → Solid
Evaporation
Liquid → Gas
Condensation
Gas → Liquid
Sublimation
Solid → Gas
Deposition
Gas → Solid
Properties of Matter
Physical Properties
Can be observed without changing the substance
Color, size, shape, texture, mass, volume
Chemical Properties
How matter reacts with other substances
Flammability, rusting, ability to react
6. Energy and Force
What is Energy?
The ability to do work or cause change. Energy cannot be created or destroyed, only transformed.
Forms of Energy
Light Energy
From the sun, bulbs, fire
Heat Energy
From fire, sun, friction
Sound Energy
From vibrations
Electrical Energy
From batteries, outlets
Mechanical Energy
From movement
Chemical Energy
Stored in food, fuel
Simple Machines
| Machine | Example | How It Helps |
|---|---|---|
| Lever | Seesaw, scissors | Lift heavy objects |
| Pulley | Flag pole, well | Lift by pulling down |
| Wheel & Axle | Car, doorknob | Move objects easily |
| Inclined Plane | Ramp, slide | Move things up easier |
| Wedge | Knife, axe | Split things apart |
| Screw | Jar lid, bolt | Hold things together |
Types of Forces
Friction
Force that opposes motion between surfaces. Rough surfaces = more friction.
Gravity
Force that pulls objects toward Earth. Makes things fall down.
Magnetism
Force between magnets. Opposite poles attract, same poles repel.
Push/Pull
Applied forces that make objects move or stop.
Key Takeaways
- ✓MRS GREN: Characteristics of living things
- ✓Photosynthesis: CO₂ + H₂O + Light → Glucose + O₂
- ✓Earth layers: Crust → Mantle → Outer Core → Inner Core
- ✓Rotation (24 hrs) = Day/Night; Revolution (365 days) = Seasons
- ✓Arteries carry blood AWAY from heart
- ✓3 states of matter: Solid, Liquid, Gas
- ✓6 simple machines: Lever, Pulley, Wheel & Axle, Inclined Plane, Wedge, Screw
- ✓Friction opposes motion; Gravity pulls down