(1 WHEN ONE BODY HAS TWO SETS OF DNA

2. MAIN IDEA

• Chimerism means one person or animal has two different DNAs inside the same body.

• It is like a body made from two tiny babies that mixed together very early.

  
  

3. HOW DOES IT HAPPEN?

1. HOW NUTRIENTS HELP YOU BREATHE ENERGY

2. MAIN IDEA

• Nutrients are the food pieces your body eats.

• Respiration is the breathing-energy process inside your cells.

• When nutrients enter your cells, respiration burns them gently to make energy.

  
  

A cell is the smallest living unit of a living thing, able to work, grow, and reproduce on its own.

FUNCTION

• A cell is the smallest living unit that keeps life going.

• It takes in food and oxygen, and turns them into energy to stay alive.

• It builds new molecules, like proteins, to grow and repair itself.

• It removes waste so toxic things don’t build up inside.

DIGESTION — WHAT IS REALLY HAPPENING?

Digestion is your body breaking giant food molecules into tiny molecules using acid, enzymes, muscles, electric signals, and special organs.

Food is made of giant chains :

• proteins

• starch

• fats

🌱 WHAT A CELL REALLY IS

A cell is a tiny bubble of life.Inside this bubble, billions of molecules keep moving, pushing, pulling, and reacting—like a tiny city that never sleeps.

This city is made mostly of water, but inside the water there are proteins that act like machines, lipids that act like walls, and sugars that act like fuel.

🐾 ANIMAL CELL

Animal cells are soft because their outer skin (membrane) is made of tiny fat molecules that wiggle.This softness helps animals bend, stretch, move, and grow.

Inside:

🌱 what is a kingdom?

a kingdom is a big group scientists made to sort all living things.every plant, animal, fungus, and tiny germ belongs to one of these five kingdoms.they are grouped by how they eat, grow, and build their body.

🦠 1. Monera – the first life

these are tiny single-celled beings — the oldest life on Earth.they have no nucleus (so their DNA just floats around).they live everywhere — in soil, hot springs, even inside you.

examples: bacteria, cyanobacteria (blue-green algae).

they:

🐸 Amphibians

Amphibians are animals that live two kinds of lives — one in water and one on land.The word “amphibian” means “double life.”

🧬 how they grow

When they are born, they start life in water as larvae (like tadpoles).They breathe with gills like fish and swim using a tail.Then, as they grow up, they go through a change called metamorphosis —their gills turn into lungs, their tails shrink, and they grow legs for land.

💧 why they need water

Even when they live on land, their skin must stay wet.Their skin helps them breathe oxygen directly from air or water.If their skin dries, they can suffocate.That’s why you’ll see frogs, salamanders, and newts in damp places.

🫀 Circulation means blood movement in the body.

It’s how oxygen, food, and waste move around using the heart and blood vessels.

But not all animals have the same kind of circulation —some have single circulation, others have double circulation.

🐟 Single Circulation (in fish)

Fish have a two-chambered heart — one atrium and one ventricle.Blood goes like this:

Heart → Gills → Body → Back to Heart

Inside every living cell, there is a kind of instruction book that controls everything the organism does — how it looks, grows, and functions.That instruction book is made of DNA, arranged into genes, and packed into chromosomes.

🧬 DNA (Deoxyribonucleic Acid)

DNA is the molecule of life.It’s a long, spiral-shaped molecule that looks like a twisted ladder, called a double helix.Each “rung” of the ladder is made from base pairs — adenine (A), thymine (T), cytosine (C), and guanine (G).The order of these bases forms a code, just like letters in a language.

That code tells the cell how to build proteins — and proteins are what make up your muscles, skin, hair, and even enzymes that run your body’s chemistry.

So, DNA is basically a chemical code that stores genetic information.

🧩 Gene

 Means grouping animals based on how they are built, how they live, and how they are related. Scientists do this to understand the huge variety of animals on Earth and their connections through evolution.

All animals are placed under the Kingdom Animalia, and from there, they are divided step by step into smaller groups: Phylum, Class, Order, Family, Genus, and Species. Each step shows how closely animals are related.

The first big division inside the animal kingdom is between invertebrates and vertebrates.

Invertebrates are animals without a backbone. They are the oldest and most common kind, making up about 95% of all animal species. They include insects, worms, jellyfish, snails, corals, and spiders. Many of them have soft bodies, and some are protected by shells or hard coverings like exoskeletons.

Vertebrates are animals with a backbone. They include fish, amphibians, reptiles, birds, and mammals. They have an internal skeleton made of bone or…

The difference between warm-blooded and cold-blooded animals.

All living creatures must keep their body temperature suitable for their cells to work. But not all do it the same way.

🔥 Warm-blooded animals

Animals like mammals and birds are called warm-blooded, or homeothermic.These creatures have a special ability — they can control their own body temperature from the inside.

Even if it’s freezing cold or extremely hot outside, their internal temperature stays almost the same.Humans, for example, maintain about 37°C constantly.

This happens because their cells burn food molecules, releasing energy as heat.That heat keeps their organs warm and their enzymes working at full speed.