Ima

1. Vegetative organs

These help the plant grow and survive:

• Root → absorbs water and minerals

• Stem → supports and transports materials

• Leaf → makes food by photosynthesis

2. Reproductive organs

Plant tissues:

Plant tissues are groups of similar cells that work together to perform a specific function.

Main types of plant tissues

1. Meristematic tissue

   • Makes new cells and helps the plant grow.

   • Found at growing regions such as root and shoot tips.

The main plant organs are:

1. Root

   • Anchors the plant in the soil.

   • Absorbs water and minerals.

   • Stores food in some plants.

2. Stem

1. Vegetative organs (help the plant grow and survive)

2. Root – Anchors the plant, absorbs water and minerals, and stores food.

3. Stem – Supports the plant and transports water, minerals, and food.

4. Leaves – Carry out photosynthesis, gas exchange, and transpiration.

5. Reproductive organs (help the plant reproduce)

6. Flower – Produces seeds through sexual reproduction.

People have different skin colors mainly because of melanin, a natural pigment made by special skin cells called melanocytes.

There are 2 chemicals named Glycene and GABA

What is melanin?

Melanin is a pigment that gives color to your:

• Skin

• Hair

Sleep paralysis is a temporary condition where you are awake or just waking up, but you cannot move or speak for a short time. It can feel very frightening, but it is usually harmless.

What happens during sleep paralysis?

• You are aware of your surroundings.

• You cannot move your body or speak.

• It usually lasts from a few seconds to a couple of minutes.

• It ends on its own.

it is usually about non-native (invasive) species entering the Sonoran Desert ecosystem.

The Sonoran Desert is a large desert that stretches across parts of Arizona, California, Sonora (Mexico), and Baja California. It is home to unique plants and animals such as saguaro cacti, coyotes, roadrunners, and Gila monsters.

Who are the intruders?"Intruders" are usually invasive species—plants or animals that do not naturally belong in the Sonoran Desert but have been introduced there.

Examples include:

• Buffalo grass – an invasive grass that spreads quickly and increases the risk of wildfires.

• Red brome – another invasive grass that competes with native plants.

Nutrients are substances in food that our body needs to live, grow, stay healthy, and get energy.

There are 6 main nutrients:

1. Carbohydrates – The body's main source of energy.

   • Examples: Rice, bread, potatoes, pasta.

2. Proteins – Help build and repair muscles, skin, and other body tissues.

   • Examples: Eggs, fish, beans, meat, milk.

Definition:Breathing (or ventilation) is the process of taking air into the lungs (inhalation) and pushing air out of the lungs (exhalation).

Two stages of breathing

1. Inhalation (Breathing in)

• The diaphragm contracts and moves downward.

• The rib muscles contract, moving the ribs up and out.

5. Age of the Earth

Scientists estimate that Earth is about 4.54 billion years old.

They found this age by studying:

• Rocks

• Fossils

• Meteorites

Structure of the Earth

The Earth has 4 main layers:

1. Crust – Outer solid layer where we live.

2. Mantle – Thick layer of hot rock beneath the crust.

3. Outer Core – Liquid iron and nickel.

4. Inner Core – Solid iron and nickel.

Geological Time Scale

The geological time scale is a timeline of Earth's history.

Major divisions:

EonImportant EventPrecambrianFirst simple life appeared Paleozoic Fish and early land animals appearedMesozoicAge of dinosaurs Cenozoic Age of mammals and humans

Scientists use fossils and rocks to divide Earth's history into these periods.

Fossil Record

The fossil record is the collection of all fossils found on Earth.

It helps scientists:

• Study ancient organisms.

• Understand how life changed over time.

• Reconstruct Earth's history.

Fossils

Fossils are the preserved remains or traces of plants and animals that lived long ago.

Examples:

• Dinosaur bones

• Shells in rocks

• Footprints

A species is a group of living things that are very similar and can produce young (offspring) together.

Examples:

• All dogs belong to the same species.

• All cats belong to another species.

• Humans are one species called Homo sapiens.

For example:

Chocolate is not always bad. Eating a small amount can be okay. But eating too much chocolate can cause problems:

Lots of sugar – Too much sugar can lead to tooth cavities and weight gain.

Less healthy food – If you eat a lot of chocolate, you may not feel hungry for healthy foods like fruits and vegetables.

Too much caffeine – Some chocolates contain caffeine, which can make it harder to sleep.

Stomach problems – Eating a lot at once can sometimes cause a stomach ache.

Energy crashes – Sugar gives quick energy, but later you may feel tired.

Chameleons change color using special cells in their skin called chromatophores.

How it works

1. Chameleons have layers of special cells under their skin.

2. These cells contain different pigments and tiny crystals.

3. When the chameleon is excited, scared, angry, cold, or trying to communicate, the cells change.

4. Light reflects differently from the skin, making the chameleon appear different colors.

Spices are aromatic plant substances (seeds, bark, roots, fruits, or flowers) used to flavor, color, and preserve food.

Some common spices include:

• Black Pepper – pungent, widely used

• Cinnamon – sweet and warm

• Turmeric – earthy, bright yellow

• Cumin – nutty and savory

Great question, Ima!

FeatureRed Blood Cells (RBCs) White Blood Cells (WBCs) Main jobCarry oxygenFight germs and infections Colour Red (contains hemoglobin) Colorless /whiteNumberVery manyMuch fewerShapeUsually round and disc-shapedDifferent shapes depending on typeNucleusNo nucleus in humansHave a nucleusLife spanAbout 120 daysDays to years, depending on the type

Red Blood Cells

• Carry oxygen from the lungs to the body.

• Carry some carbon dioxide back to the lungs.

• Contain hemoglobin, which gives blood its red color.

1. Solid

• Has a fixed shape and fixed volume

• Particles are tightly packed and vibrate in place

• Strong intermolecular forces

Examples

• Ice

Organs” generally refers to specialized body structures made of different tissues that work together to perform specific functions in living organisms.

In humans and many animals, major organs include:

• Heart — pumps blood

• Lungs — exchange oxygen and carbon dioxide

• Brain — controls the nervous system

• Liver — processes nutrients and detoxifies substances

The brain is one of the most important organs in the human body.

What the Brain Does

• Helps you think

• Stores memories

• Controls movement

• Helps you learn

Material properties describe how a substance behaves under different conditions, including its mechanical strength, thermal stability, electrical conductivity, and chemical resistance. These properties determine how materials are selected and used in engineering, construction, electronics, and everyday products.

Categories of Material Properties

• Mechanical properties

  • Tensile strength, hardness, toughness, elasticity, ductility, fatigue resistance.

  • Example: Steel has high tensile strength, while rubber is highly elastic.

• Thermal properties

Cells:

• Cells are the basic structural and functional units of life.

• They carry out essential processes like energy production, protein synthesis, and waste removal.

• Examples: muscle cells, nerve cells, blood cells.

Tissues

• Tissues are groups of similar cells working together to perform a specific function.

Human nutrition is the science of how food sustains life, providing energy and essential nutrients for growth, repair, and overall health. It focuses on macronutrients (carbohydrates, proteins, fats) and micronutrients (vitamins, minerals, water), aiming to prevent malnutrition and reduce chronic disease risks.

Questions:

1.Why do they have to study it ?

ANS : Studying human nutrition is essential because it directly impacts health, disease prevention, productivity, and even social and economic development. Without understanding nutrition, societies face higher risks of malnutrition, obesity, chronic illnesses, and reduced quality of life.

2. What will happen to humans if people don't study human nutrition?

ANS: If people stopped studying human nutrition, the consequences would be serious and far-reaching. Nutrition science is the backbone of public health, disease prevention, and food policy. Without it, humans would face both immediate and long-term risks.

Cells are the building block of life. We are made of cells. Almost every bacteria and fungi are unicellular organisms. Unicellular organisms means one celled organisms. we are multicellular organisms. Multicellular organisms have more than one celled organisms. There are 2 types of cells animal cell and plant cell.

Question

Did unicellular organisms come first on Earth?

ANS: Yes unicellular organisms came first on earth.

The immune system is your body's defence system. It products your body from harmful bacteria and germs. Germs and bacteria is every were, so to fight with the bad germs and bad bacteria.

How it happens:

When a germ enters for the first time

then you get sick but if that same germ enters the body for the 2nd time and all you won't get sick because your immune system knows this.

Human nutrition is the study of how your body takes in food and what is healthy like vegetable so they study how is vegetable good for your body what all nutrients has like that they study also about water to maintain life, support growth, and maintain health it focuses on the essential nutrients that provide energy and structural materials for our tissues. The body requires seven major classes of nutrients, divided into macronutrients and micronutrients.

Macronutrients:

• Carbohydrates: The primary energy source for cellular respiration, found in grains and starchy vegetables.

• Proteins: Vital for growth and tissue repair, sourced from meat, eggs, and legumes.

• Fats : Provide long-term energy storage and insulation.

• Water: Critical for chemical reactions and transporting nutrients to cells.

1. Wagging tail

   Wagging tail means the dog is emotionally aroused .

Question

What is meant by emotionally aroused?

Ans: Emotionally aroused means your body and mind are on high alert.

For example: A dog is excited , scared or angry.

In the air there is harmful and deadly microorganisms like fungi, bacteria and virus that can harm you so your body developed a mechanism called the immune system to protect your body. An immune system is not only one part but a combination of tissues, organs ,and cells some of which is lymphatic nodes , limp vessels , lymphocytes , white blood cells , bone marrow, skin ...

That join to protect you and keep you alive . White blood cells, also called leukocytes . Which play an important roll , in the immune system by continuously Scanning tissues and organs for any suspicious signs . as soon as a foreign substance called antigenes cut your first layer of defence which is the skin , and enters our body . It quickly begins to use your vital resources and starts to double up in number with in a few minutes…

DNA short form for deoxyribonuclic acid is a molecules a group of atoms stuck together in the shape of dobble helix. Its the genitic code that Determines all the characterstics that forms living organisms. we are made of 3 billion cell that we can't see, and each cell has a spcefic job. some banch of cells make up our bone some make our brain some make our skin and all together makes our body. DNA tells every cell what to do. DNA is like a blueprint for our body.

What is amino acid?

The amino acid is an needed chemical inside our body and its often referred to basic bulding block of life. they come in 20 different shapes an kinds of chemicals it stays coiled up inside the nucles which is inside cytoplasm and which is inside the cell.

When blinking hapence you are actully mosturing your eye, eye ball , there is also a layer to protect you from dust so this too. So when you don't blink your eye dust mostureise so your eye , eye ball and the layer will get try. Also when you blink it blocks dust too so when you don't blink dust can pass through which cause eye itches. Also when your eye vanes will break after few hours so when it hapence you eye will start getting red in colour and start burring and itching then if you still hold it like that for some more time then that layer of your eye will break and also if you still keep it for days your brain will forget how to blink so it is better to blink when needed

Elephants belong to the elephantipae family and to the probosicided order. That includes sea cows, elephant and Hyrxes. Elephants can grow up to 13 feet tall and can weigh up to 13,000 pounds. early elephants were very different in there sizes apperance back then compared to what we see of them today. It started with a species known as ''moeitherium'' and were heavily about 3 feet tall . They didn't have trunks like mordern day elephants. Had abroud , flexible upper lip like a tapits for grasping aquatic vegetations. Then came the byatheriume the most important feature that was changed from would be the small tusks That were on the upper and lower jaw. This was changed because the need to be able to have the shearing action to crop plants. Then about 26 millone years ago came the ''numidotherium'' with much slender body shape and not much changed un…

What are microorganisms?

Microorganisms are tiny living things you can’t see with your eyes. Examples include:

• Bacteria

• Fungi (like yeast)

• Some algae

How microorganisms HELP us in food

Definition

Whales are large marine mammals that live in oceans, breathe air through blowholes, and give birth to live young.

Main Points

• Live in oceans 

• Breathe air using a blowhole 

• Are warm-blooded mammals

Definition

The Blue whale is the largest animal on Earth, a sea-living mammal that eats tiny krill using baleen plates.

Main Points

• Lives in oceans around the world 

• Breathes air through a blowhole 

• Eats krill using baleen plates 

Definition

The blue whale is the largest animal on Earth, a marine mammal that lives in oceans and feeds on tiny krill using baleen plates.

Main Points

• Lives in oceans all over the world 

• Breathes air using a blowhole 

• Eats krill using baleen plates 

Blue Whale

• Size: Can grow up to 30 meters long (about the length of 3 buses!)

• Weight: Around 150–200 tons (as heavy as 30 elephants!)

Where do they live?

Blue whales live in all the world’s oceans, from cold polar waters to warmer seas.

What do they eat?

• The play bow is a universal gesture among dogs indicating their desire to play and that their actions are friendly.

• Dogs use the play bow to communicate with humans and other animals, often preceding playful behavior.

• Owners can mimic a play bow to engage their dogs in play, effectively "speaking" their language.

If you've been around even just a few dogs in your life, you've probably witnessed the play bow. It's a posture that dogs of all ages, breeds, and sizes take when they want to have fun.

A play bow is a form of dog body language. It’s a way in which dogs communicate with people and other animals. Essentially, it's your dog's way of saying, "Let's play!"

Animal communication systems

involve the transfer of information from one individual (the sender) to another (the receiver), often resulting in a change in the receiver's behaviour. These systems are essential for survival, helping animals find food, attract mates, defend territory, and warn others of predators.

Primary Modes of Communication

Animals use various sensory channels to transmit signals:

Acoustic (Sound): Rapid and wide-reaching. Includes vocalizations like bird songs and wolf howls, or non-vocal sounds like a beaver slapping its tail on water.

Visual: Involves gestures, body postures, facial expressions, and coloration. Examples include a peacock fanning its tail or a dog baring its teeth.

The Human skeletal system is the framework of bones inside our body. It gives our body shape, support, and protection.

1. Number of bones

An adult human has 206 bones in the skeletal system.

2. Main functions

The skeletal system has several important jobs:

• Support: It holds the body up and gives it shape.

Human Organ Systems

A human organ system is a group of organs that work together to perform a specific function in the body. The human body has many organ systems, and each system helps the body stay alive and function properly.

1. Skeletal System

The skeletal system is made up of bones, cartilage, and joints. An adult human has 206 bones. This system gives shape and support to the body, protects internal organs, and helps in movement by working with muscles. For example, the skull protects the brain and the rib cage protects the heart and lungs

2. Muscular System

The muscular system is made up of muscles that help the body move. Muscles work together with bones to allow movement such as walking, running, and lifting objects. Muscles also help maintain posture and produce heat in the body.

Plant Organs

Plant organs are specialized parts of a plant that perform specific functions. The main plant organs are roots, stems, leaves, flowers, fruits, and seeds. These organs work together to help the plant survive, grow, and reproduce.

Roots

Roots are usually found underground and form the plant’s anchoring system. They absorb water and minerals from the soil and transport them to the stem. Some roots also store food for the plant.

Types of roots:

• Tap root – one thick main root with smaller branches (example: carrot)

1. The ozone layer is formed naturally in the Stratosphere.

2. It forms when ultraviolet (UV) rays from the Sun react with oxygen molecules.

3. Ozone is a gas made of three oxygen atoms (O₃).

4. The ozone layer helps absorb a large amount of harmful UV radiation.

5. Some UV rays still pass through the ozone layer and reach Earth.

6. When UV rays reach our skin, they can affect skin cells.

Adaptation 

means special features or behaviors that help animals survive in their habitat.

Habitat = the place where an animal lives.

Animals adapt to:

• Get food

• Protect themselves

Reproduction 

is the process by which living things produce new living things of the same kind.

It is important because it helps living organisms continue their species.

Types of Reproduction

There are two main types:

Asexual Reproduction

What does “endangered” mean?

It means very few of them are left on Earth, so they might become extinct.

Why do species become endangered?

• Loss of habitat (cutting forests, building cities)

• Hunting and poaching

What is variation?

Variation means differences between living things of the same kind.

Example:

All humans are the same species, but we have different:

• height

• skin colour

Variation in Species

Variation means differences.So, variation in species means differences among living things of the same species.

What is a Species?

A species is a group of living things that are similar and can have babies together.Example: All humans are one species.

Examples of Variation

Even in the same species, no two are exactly the same!

What is a Species?

A species is a group of living things that are similar and can have babies together.Example: All humans are one species.

Examples of Variation

Even in the same species, no two are exactly the same!

In humans

A species is a basic group in living things used by scientists.

Living things of the same species:

Look almost the same

Have the same body parts

Live in similar ways

Can reproduce and have babies together

Energy Resources

Definition:

Energy resources are things from nature that give us energy to do work like lighting, heating, cooking, moving vehicles, and making electricity.

Main Types of Energy Resources

1. Renewable Energy Resources

These do not finish and can be used again and again.

Simple meaning:

Conservation is taking care of nature and resources so they are available for the future.

Examples:

• Conserving forests – not cutting too many trees, planting new ones

• Conserving water – turning off taps, not wasting water

• Conserving electricity – switching off lights and fans when not needed

Ozone Depletion

Ozone depletion means the thinning of the ozone layer in the Earth’s atmosphere.

What is the ozone layer?

• It is a protective layer of gas high up in the sky.

• It protects us from harmful UV (ultraviolet) rays from the Sun.

What causes ozone depletion?

Pollution:

Definition:

Pollution is when harmful things make air, water, or land dirty and unsafe for living beings.

Types of Pollution

1. Air pollution – Smoke from vehicles and factories makes the air dirty.

2. Water pollution – Waste and chemicals pollute rivers, lakes, and seas.