Rules to be alive - StudyBuddy

1 Living vs. Non-Living: The 7 Life Processes

A colorful split illustration showing a playful puppy running (living) on the left and a shiny toy robot (non-living) on the right, with icons representing the 7 life processes floating between them.

How do you know if your pet rock is actually alive? 🪨 vs 🐕. It is not just about moving! Scientists use a special checklist called MRS GREN to decide.

🌿 The 7 Rules of Life (MRS GREN)

Movement 🏃 Changing position
Respiration 🫁 Releasing energy from food
Sensitivity 👀 Noticing changes around you
Growth 🌱 Getting bigger or changing shape

Reproduction 🐣 Making new offspring
Excretion 🚽 Getting rid of waste
Nutrition 🍎 Taking in food/fuel

Compare: Robot vs. Human

Action	Human (Living) 🧍	Robot (Non-Living) 🤖
Fuel	Eats food for nutrition	Uses electricity/batteries
Growth	Grows from baby to adult	Stays the same size forever
Senses	Feels pain, heat, cold	Sensors detect data, but no 'feeling'

💡 Think about it: Fire moves, consumes oxygen, and grows. Is it alive?
No! It cannot reproduce biologically and is not made of cells.

Key Facts

✅ All living things must do ALL 7 processes, not just a few!

🌻 Plants are alive too! They move towards light and eat sunlight.

⚡ Respiration is not just breathing; it is making energy inside cells.

2 Fueling Up: Nutrition and Respiration

A split illustration showing a sunflower absorbing sunlight on the left, and a child eating an apple on the right, with arrows pointing to a battery icon representing energy.

Imagine your body is a high-tech car. To keep running, it needs two things: fuel (food) and oxygen to burn that fuel. Let's look at how living things power up!

🌱 Nutrition: Getting the Fuel

Nutrition is how organisms take in materials from their environment to grow and repair themselves. There are two main strategies:

Autotrophs (Self-feeders): Like plants! They use sunlight to cook up their own food through photosynthesis.
Heterotrophs (Other-feeders): Like humans and dogs! We must eat plants or other animals to get energy.

💨 Respiration: Burning the Fuel

Respiration is NOT just breathing! It is a chemical process happening inside your cells right now.

Food (Glucose) + Oxygen = ENERGY ⚡

When you breathe in oxygen, it travels to your cells to unlock the energy stored in your food. The waste product is Carbon Dioxide (CO2), which you breathe out!

Comparison: Plants vs. Animals

Action	Plants 🌻	Animals 🐯
How they get food	Make it using sunlight (Photosynthesis)	Hunt, gather, or buy it (Ingestion)
Gas needed	Mostly Carbon Dioxide (CO2)	Oxygen (O2)
Energy Goal	To grow leaves, roots, and flowers	To move, think, and keep warm

Key Facts

🍽️ Autotrophs make their own food; Heterotrophs must eat others.

⚡ Cellular respiration turns sugar and oxygen into energy.

🍃 Plants 'breathe' too! They exchange gases just like animals.

3 Action and Reaction: Movement and Sensitivity

A split illustration showing an animal reaction on one side (a cat jumping away from a surprise) and a plant reaction on the other (a plant bending towards a light bulb).

Have you ever pulled your hand away from something hot without thinking? 🖐️🔥 Or watched a sunflower turn its head to follow the sun? 🌻 That is Sensitivity and Movement in action!

👀 Sensitivity: The Super Sense

All living things are like detectives. They detect changes in their environment called Stimuli and react to them with a Response.

Stimulus: A loud noise 📢
Response: Covering your ears 🙉

We use our five senses to detect these changes. Even tiny bacteria can sense food nearby!

🏃 Movement: Not Just Running

When we think of movement, we usually think of locomotion (moving from place to place). But did you know plants move too?

Animals: Can walk, fly, or swim to find food or escape danger. 🐆
Plants: Move by growing. Roots grow down towards water, and stems grow up towards light. 🌱

🆚 Comparison: How do they react?

Feature	Animals 🐶	Plants 🌿
Reaction Speed	Usually fast (running away)	Usually slow (growing towards light)
Movement Type	Locomotion (whole body moves)	Growth movement (parts move)
Purpose	Find food, shelter, mates	Absorb maximum sunlight and water

💡 Did You Know? The Venus Flytrap is a plant that breaks the rules! It can snap its leaves shut in less than a second to catch insects. That is fast plant movement! 🪰🌱

Key Facts

⚡ Sensitivity is the ability to detect and respond to changes in the environment.

🏃 Not all living things can move from place to place (locomotion), but all living things move parts of themselves.

🌱 Plants usually move slowly by growing towards what they need, like light or water.

4 The Cycle of Life: Growth, Reproduction, and Excretion

A three-part educational diagram showing: 1. A seedling growing into a tree (Growth), 2. A mother duck with ducklings (Reproduction), and 3. A human jogging and sweating (Excretion).

🔄 The Journey of Being Alive!

Being alive isn't just about eating and moving. It is a continuous cycle! Living things start small, get bigger, make copies of themselves, and must keep their bodies clean on the inside.

🌱 Growth

Have you noticed your pants getting shorter? That's growth! It doesn't just mean getting bigger like a balloon; it means your body is making more cells.

🐣 Start: A single cell.
💪 Process: Cells divide and specialize.
🌳 Result: A complex organism (like you!).

🐣 Reproduction

Living things don't live forever, so they must produce offspring (babies or seeds) to keep their species from disappearing. This is called reproduction.

Examples: A cat having kittens, an apple tree dropping seeds, or bacteria splitting in two.

🚮 Excretion

Your body is like a factory. It takes in materials, but it also creates trash! Excretion is how we get rid of waste so it doesn't poison us.

Not just the bathroom! Sweating and breathing out CO₂ are also excretion.

🗑️ How Do We Get Rid of Waste?

Type of Waste	Example	How it leaves the body
Gas 💨	Carbon Dioxide (CO₂)	Lungs (Breathing out)
Liquid 💧	Urine & Sweat	Kidneys & Skin
Solid 💩	Undigested Food	Digestive System

Key Facts

📈 Growth happens because your cells divide to make more cells, not just because they stretch.

⚠️ Excretion is essential because waste products can be toxic (poisonous) if they stay inside us.

🦁 Reproduction ensures the survival of the species, even if individual organisms pass away.

5 Cells: The Building Blocks of Life

A split illustration showing a puppy growing into a dog on the left (living) and a toy robot staying the same on the right (non-living), with a magnifying glass showing cells on the dog.

🤔 The Big Question: Is it Alive?

Imagine a cloud moving across the sky. It moves, it grows, and it changes shape. Is it alive? No! To be officially 'alive' in science, an organism must follow specific rules. Let's look at the checklist of life!

The 5 Golden Rules of Life 🌱

🧱 1. Made of Cells: Just like a LEGO® castle is made of bricks, every living thing is made of at least one cell.
⚡ 2. Use Energy: You eat pizza 🍕; plants use sunlight ☀️. Living things need fuel to survive.
📈 3. Grow and Develop: A tiny acorn becomes a giant oak tree. Living things get bigger and change over time.
🐣 4. Reproduce: Living things make copies of themselves (babies, seeds, or dividing cells).
👀 5. Respond to Change: If you step on a sharp rock, you jump! Living things react to their surroundings.

Robot vs. Hamster 🐹

Why isn't a smart robot alive?

Feature	🤖 Robot	🐹 Hamster
Moves?	✅ Yes	✅ Yes
Uses Energy?	✅ Yes (Battery)	✅ Yes (Food)
Made of Cells?	❌ No (Metal)	✅ Yes!
Grows?	❌ No	✅ Yes!

Even though robots are smart, they don't grow or have cells!

Key Facts

🦠 All living things are made of one or more cells.

⚖️ Living things maintain a stable internal environment (Homeostasis).

🪨 Biotic means living; Abiotic means non-living (like water or rocks).

6 Key Vocabulary

Master these important terms for your exam:

Term	Definition
Organism Organismo	Any individual living thing that demonstrates all the characteristics of life. Cualquier ser vivo individual que demuestra todas las características de la vida.
Cell Célula	The smallest basic unit of structure and function in living things. La unidad básica más pequeña de estructura y función en los seres vivos.
Unicellular Unicelular	An organism made of only one single cell (like bacteria). Un organismo formado por una sola célula (como las bacterias).
Multicellular Pluricelular	An organism composed of many cells specialized to perform different functions. Un organismo compuesto por muchas células especializadas para realizar diferentes funciones.
Homeostasis Homeostasis	The ability to maintain a stable internal environment despite changes outside. La capacidad de mantener un ambiente interno estable a pesar de los cambios externos.
Metabolism Metabolismo	The total of all chemical reactions an organism uses to build up or break down materials for energy. El total de todas las reacciones químicas que un organismo utiliza para construir o descomponer materiales para obtener energía.
Stimulus Estímulo	A change in an organism's surroundings that causes the organism to react. Un cambio en el entorno de un organismo que hace que este reaccione.
Response Respuesta	An action or change in behavior that occurs as a result of a stimulus. Una acción o cambio de comportamiento que ocurre como resultado de un estímulo.
Reproduction Reproducción	The process by which living things produce new individuals of the same type. El proceso mediante el cual los seres vivos producen nuevos individuos del mismo tipo.
Asexual Reproduction Reproducción asexual	Reproduction involving only one parent, producing offspring identical to the parent. Reproducción que involucra a un solo progenitor, produciendo descendencia idéntica al progenitor.
Sexual Reproduction Reproducción sexual	Reproduction involving two parents combining genetic material to create unique offspring. Reproducción que involucra a dos progenitores que combinan material genético para crear descendencia única.
DNA ADN	The genetic material that carries information about an organism and is passed from parent to offspring. El material genético que transporta información sobre un organismo y se transmite de padres a hijos.
Growth Crecimiento	The process of becoming larger in size. El proceso de aumentar de tamaño.
Development Desarrollo	The process of change that occurs during an organism's life to produce a more complex organism. El proceso de cambio que ocurre durante la vida de un organismo para producir un organismo más complejo.
Autotroph Autótrofo	An organism that makes its own food, usually through photosynthesis (also called a producer). Un organismo que fabrica su propio alimento, generalmente a través de la fotosíntesis (también llamado productor).
Heterotroph Heterótrofo	An organism that cannot make its own food and must feed on other organisms (also called a consumer). Un organismo que no puede fabricar su propio alimento y debe alimentarse de otros organismos (también llamado consumidor).

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