Transportation in Plants and Animals- Complete Guide For Class 7th Science Chapter 7

Welcome to iPrep, your Learning Super App. Our learning resources for the chapter, Transportation in Plants and Animals in Science for Class 7th are designed to ensure that you grasp this concept with clarity and perfection. Whether you’re studying for an upcoming exam or strengthening your concepts, our engaging animated videos, practice questions and notes offer you the best of integrated learning with interesting explanations and examples.

Today we’re diving into Chapter 7 of Class 7 Science: “Transportation in Plants and Animals.” We’ll explore how both plants and animals manage the movement of essential substances within their bodies to stay healthy and functional. Let’s break it down into easy-to-understand sections, complete with tables, flowcharts, and equations for better comprehension.

Understanding Transportation In Plants And Animals

Transportation in Plants and Animals refers to the movement of substances and gases from one part of a multicellular organism to another. This process is vital for maintaining life as it ensures that all cells receive the nutrients and oxygen they need while removing waste products.

Transportation in Humans

The Circulatory System

In the chapter Transportation in Plants and Animals, there is a detailed mention of transportation in humans. In humans, transportation is handled by the circulatory system, which includes:

Heart: The muscular pump that drives blood through the body.
Blood: The fluid medium that carries nutrients, gases, and waste products.
Blood Vessels: The tubes through which blood flows.
Lymph: An additional fluid medium involved in transportation.

A visual representation of the circulatory system which is a part of Class 7 math chapter 7 - Transportation in Plants And Animals

Components of the Circulatory System

Component	Function
Heart	Pumps blood throughout the body
Blood	Transports nutrients, gases, and waste products
Blood Vessels	Carry blood to and from all parts of the body
Lymph	Transports fats and drains excess fluid

Blood Composition

According to the chapter Transportation in Plants And Animals, Blood is composed of:

Red Blood Cells (RBCs): Carry oxygen from the lungs to the body and return carbon dioxide.
White Blood Cells (WBCs): Also known as leukocytes, part of the immune system, fighting infections.
Platelets: Aid in blood clotting to prevent bleeding.
Plasma: The liquid component that transports cells and nutrients.

A visual of the composition of blood from the chapter - Transportation in plants and animals

Table of Blood Components

Component	Function
Red Blood Cells	Transport oxygen and carbon dioxide
White Blood Cells	Fight infections
Platelets	Form blood clots
Plasma	Carries cells and nutrients

Blood Vessels

According to the chapter Transportation in Plants and Animals, Blood vessels are categorized into:

Arteries: Carry oxygenated blood away from the heart.
Veins: Carry deoxygenated blood back to the heart.
Capillaries: The smallest blood vessels where nutrient and gas exchange occurs.

A visual illustration of capillaries from class 7th science chapter 7 - Transportation in Plants And Animals

Comparison of Blood Vessels

Type	Function	Structure
Arteries	Carry oxygenated blood	Thick walls, no valves
Veins	Carry deoxygenated blood	Thin walls, with valves
Capillaries	Exchange of gases and nutrients	One cell thick walls

The Heart

The heart is a muscular organ with four chambers:

Right Atrium and Right Ventricle
Left Atrium and Left Ventricle
Valves between atria and ventricles.
The partition between the chambers helps to avoid mixing up blood rich in oxygen with blood rich in carbon dioxide
Helps in pumping blood to body parts

Diagram of the Human Heart

Heart Chambers in Various Animals:

Fish: Two chambers
Amphibians: Three chambers
Reptiles: Three chambers
Birds and Mammals: Four chambers

Heartbeat

The heartbeat is one complete contraction of the heart and continues throughout life. A stethoscope is used to listen to the heartbeat and consists of:

Chest Piece (with a sensitive diaphragm)
Two Ear Pieces
Connecting Tube

Lymph

Lymph is an extracellular colorless fluid which contains blood (large proteins and RBCs) that helps in:

Transportation of fats
Draining excess fluid back into the blood

Formation of Lymph

Leakage of small cells and proteins from blood

Circulation

Types of Circulation:

Single Circulation: Blood passes through the heart once (e.g., fish).
Double Circulation: Blood passes through the heart twice (e.g., humans).

Flowchart of Blood Circulation

[Body] -> [Heart (Right)] -> [Lungs] -> [Heart (Left)] -> [Body]

Excretion

The Process of Excretion

Excretion is the removal of metabolic wastes from the body:

Carbon Dioxide: Removed through the lungs.
Nitrogenous Wastes (Urea, Uric Acid): Removed through the urinary system.

The Human Excretory System

Filtration and Urine Formation

Filtration: Done by capillaries in the kidneys.
Reabsorption: Useful substances are reabsorbed back into the blood.
Urine Formation: Wastes dissolved in water are removed as urine.

A visual representation of nephron - The excretory unit from class 7th Science chapter 7- Transportation in Plats and Animals

Urine = Nitrogenous Wastes + Water

Filtration of wastes from the blood.
Selective reabsorption of certain substances like glucose, amino acids, salts and water back into the blood.
Urination is under the nervous control.

Flowchart of Urine Formation

[Blood] -> [Kidneys] -> [Urine Formation] -> [Ureters] -> [Bladder] -> [Urethra]

Daily Urine Output: Approximately 1-1.8 liters

Excretion in humans also takes place through sweating. On hot summer days, sweating takes place. Sweat contains water and salts.

Excretion in Other Animals

Fish: Excrete ammonia in gaseous form.
Reptiles, Birds: Excrete uric acid as a semi-solid compound.

Dialysis

In cases of kidney failure, dialysis is used to clean waste from the blood artificially.

Excretion in Plants

Transportation in Plants

Need for Transportation

Plants need to transport:

Water and Minerals: For food preparation and growth.
Food and Other Substances: To support various parts of the plant.

Transport of Water and Minerals

Absorption: Water and minerals are absorbed by the roots, facilitated by root hairs.
Xylem Tissue: Made up of vessels and tracheids. These form a continuous water-conducting system from roots to leaves.

Flowchart of Water Movement in Plants

[Soil] -> [Roots] -> [Xylem] -> [Leaves]

Transpiration: Evaporation of water through the leaves, creating suction that pulls water up. It’s a process by which water that is absorbed by plants, usually through the roots, is evaporated into the atmosphere through the stomata present on the surface of the leaves.

Transport of Food (Translocation)

Phloem Tissue: Transports food from leaves to other parts.
Two-Way Flow: Due to osmotic pressure created by the movement of sucrose in the phloem.

A visual representation of Transport of Food and other substances (Translocation) from the chapter - Transportation in Plants And Animals

Flowchart of Food Transport

[Leaves] <-> [Phloem] <-> [Other Parts]

Conclusion

In conclusion, Chapter 7: Transportation in Plants and Animals in Class 7 Science is a fundamental topic that explores how living organisms, both plants and animals, efficiently manage the movement of essential substances to maintain life. Through the circulatory system in animals and the vascular system in plants, transportation plays a key role in ensuring proper nutrition, gas exchange, and waste removal. Understanding these processes from Class 7 Science Chapter 7: Transportation in Plants and Animals gives students a strong foundation in biology, highlighting the complexity and importance of internal systems in sustaining life.

With the resources offered by iPrep Learning Super App, you can deepen your understanding of Class 7 Science Chapter 7: Transportation in Plants and Animals through interactive videos, practice questions, and detailed notes. Don’t miss out on mastering this essential chapter – ensure you review all the key points discussed in Transportation in Plants and Animals for your upcoming exams and further learning!

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Respiration in Organisms- Complete Guide For Class 7th Science Chapter 6

Welcome to iPrep, your Learning Super App. Our learning resources for the chapter, Respiration in Organisms in Science for Class 7th are designed to ensure that you grasp this concept with clarity and perfection. Whether you’re studying for an upcoming exam or strengthening your concepts, our engaging animated videos, practice questions and notes offer you the best of integrated learning with interesting explanations and examples.

If we run fast, we breathe fast. This is because breathing is an integral part of respiration, a vital process for all living beings. Let’s explore how organisms respire and how this process supports life in our chapter on respiration in organisms.

Cellular Functions and Energy

Each cell in an organism performs essential functions such as nutrition, reproduction, transportation, and excretion. To carry out these functions, cells need energy, which is provided by respiration.

Let’s understand respiration in organisms in detail, including its steps and types.

What is Respiration in Organisms?

A visual illustration of Respiration in organisms from class 7 math chapter 6

Respiration is the process of oxidizing organic components to produce energy in the form of ATP molecules.

Steps of Respiration in Organisms

Oxidation of Glucose: The first step occurs in the cell cytoplasm where glucose is oxidized. This process is known as glycolysis, which breaks down glucose into two molecules of pyruvate, producing a small amount of ATP and NADH in the process.
Formation of Acetyl-CoA: Pyruvate, the product of glucose oxidation, is transported into the mitochondria. Here, it undergoes oxidative decarboxylation to form acetyl-CoA. This step generates carbon dioxide and NADH.
Krebs Cycle (Citric Acid Cycle): Acetyl-CoA enters the Krebs cycle, which occurs in the mitochondrial matrix. During this cycle, acetyl-CoA is further oxidized, producing ATP, NADH, FADH₂, and carbon dioxide as waste products.
Electron Transport Chain (ETC): NADH and FADH₂ produced in the previous steps donate electrons to the electron transport chain located in the inner mitochondrial membrane. The electrons move through a series of proteins and generate a proton gradient across the membrane.
Oxidative Phosphorylation: The proton gradient created by the electron transport chain drives the synthesis of ATP through ATP synthase in a process called chemiosmosis. Oxygen acts as the final electron acceptor, combining with electrons and protons to form water.
Fermentation (if no oxygen is present): In the absence of oxygen, pyruvate undergoes fermentation. In animals, this produces lactic acid, while in yeast and some bacteria, it results in ethanol and carbon dioxide. This process allows for ATP production without oxygen but is less efficient.

Types of Cellular Respiration

Aerobic Respiration

Definition: Oxidation of food in the presence of oxygen to release energy and carbon dioxide.
Location: Occurs in the mitochondria.

Anaerobic Respiration

Definition: Oxidation of food in the absence of oxygen.
Location: Occurs in the cytoplasm.
Types:
- Fermentation in Yeast: Oxidation of pyruvate to produce ethanol, carbon dioxide, and energy.

Lactic Acid Process: Oxidation of pyruvate by muscle cells to produce lactic acid and energy.

Let’s move to the concept of breathing and the mechanism involved in it.

Breathing

A visual representation of the human respiratory system from class 7 science chapter 6 - Respiration in organisms

Definition: Breathing is the physiological process by which oxygen is drawn into the body and carbon dioxide is expelled. This essential function supports cellular respiration and overall metabolic processes.

Mechanism

Inhalation: This is the process of drawing air into the lungs. During inhalation, the diaphragm contracts and moves downward, while the rib cage expands outward. This creates a negative pressure within the thoracic cavity, causing air to flow into the lungs through the airways.
Exhalation: This is the process of expelling air from the lungs. During exhalation, the diaphragm relaxes and moves upward, and the rib cage contracts. This reduces the volume of the thoracic cavity, increasing the pressure and forcing air out of the lungs.

Role of the Diaphragm and Rib Cage In Breathing

Diaphragm: The diaphragm is a dome-shaped muscle located at the base of the thoracic cavity. Its contraction and relaxation are crucial for altering the volume of the chest cavity, facilitating the flow of air in and out of the lungs.
Rib Cage: The rib cage provides structural support and protection for the lungs and heart. During breathing, the intercostal muscles (located between the ribs) work to expand and contract the rib cage, assisting in the process of inhalation and exhalation.

Together, these components ensure efficient gas exchange and maintain proper oxygen and carbon dioxide levels in the blood.

Mechanism of Breathing

a visual representation of the mechanism of breathing from class 7 science chapter 6 - respiration in organisms

Action	Ribs Movement	Diaphragm Movement
Inhalation	Ribs move up and outwards	Diaphragm moves down
Exhalation	Ribs move down and inwards	Diaphragm moves up

Smoking

Smoking involves inhaling smoke from burned substances, most commonly tobacco.
Smoking is harmful and can cause lung cancer.

Breathing in Animals

Similarities: Animals like cows, tigers, and dogs have lungs similar to humans.
Differences: Insects, earthworms, and other smaller animals have different respiratory systems.

Insects

Respiratory System: A complex network of tubes called trachea.
Air Intake: Through spiracles, valve-like openings on their bodies.
Gas Exchange: Air passes through spiracles into tracheal tubes, diffuses into body tissues, and reaches every cell. Carbon dioxide follows the reverse path.

Earthworms

Respiratory Organ: Moist outer skin.
Process: Oxygen diffuses across the skin into blood capillaries, which transport it to body cells. Carbon dioxide is transported back to the skin and diffuses out.

Frogs

Frogs have lungs and can also breathe through their skin.

Breathing Underwater

Aquatic Animals: Need to obtain oxygen from water.
Whales and Dolphins: Come to the surface to breathe.
Fish: Use gills, which are well supplied with blood vessels, to extract oxygen from water.

Breathing in Plants

Gas Exchange: Takes place through stomata by simple diffusion.
Respiration Process:
- Plants use oxygen from the air and stored sugars to produce carbon dioxide and water.
- Roots also need oxygen, which they take up from air spaces between soil particles.

Plant Respiration Formula

C6H12O6 + 6O2 –> 6CO2 + 6H2O + Energy

This comprehensive overview of respiration in organisms provides a clear understanding of how living beings obtain and utilize energy to sustain life.

In conclusion, Class 7 Science Chapter 6 – Respiration in Organisms offers an insightful exploration into the essential process of respiration across various organisms. Through understanding Respiration in Organisms, we learn how energy is crucial for cellular functions and how different organisms adapt their respiratory mechanisms to survive. From the intricate steps of cellular respiration to the comparative study of breathing across species, this chapter equips you with a profound comprehension of life’s vital processes.

As you delve into Respiration in Organisms, you’ll uncover the fascinating ways in which different creatures, from insects to aquatic animals, execute respiration and maintain their life processes. The chapter also sheds light on the impact of human activities, such as smoking, on respiratory health. By integrating the knowledge of Respiration in Organisms with practical examples and engaging resources, you can better appreciate the complexity and importance of respiration in sustaining life.

Remember, mastering Respiration in Organisms is not just about memorizing facts but understanding how these processes contribute to the energy dynamics of all living beings. Keep exploring and applying these concepts to enhance your learning experience and grasp the fundamental principles of life science.

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Acids Bases and Salts- Complete Guide For Class 7 Science Chapter 4

Welcome to iPrep, your Learning Super App. Our learning resources for the chapter, Acids Bases and Salts in Science for Class 7th Chapter 4 are designed to ensure that you grasp this concept with clarity and perfection. Whether you’re studying for an upcoming exam or strengthening your concepts, our engaging animated videos, practice questions and notes offer you the best of integrated learning with interesting explanations and examples.

A visual illustration of acids bases and salts from class 7 science chapter 4 - Acids, Bases, and Salts

Understanding the acids bases and salts of Class 7 Chapter 4 is fundamental to comprehending basic chemistry. This chapter provides insights into the tastes and properties of various substances and their classifications as acids or bases. It also explores natural indicators and the phenomenon of neutralization in everyday life.

Tastes of Edible Substances

While understanding the concepts of acids bases and salts, let’s recall the tastes of some edible substances:

Substances	Taste
Curd	Sour
Mango	Sour
Tamarind	Sour
Amla	Sour
Vinegar	Sour
Orange juice	Sweet and Sour
Grapes	Sweet and Sour
Baking soda	Bitter
Salt	Salty

What is an Acid?

Within the chapter Acids bases and salts, we first start with understanding what is an Acid. What do lemon, tamarind (imli), curd, and vinegar have in common? They all taste sour because they contain acids. The term “acid” comes from the Latin word “acere,” meaning sour. Naturally occurring acids in these substances are called neutral acids.

Now, Let’s take a look at some common acids present in substances around us.

Common Acids in Substances

Name of Acid	Found In
Acetic acid	Vinegar
Formic acid	Ant’s sting
Citric acid	Citrus fruits
Lactic acid	Curd
Oxalic acid	Spinach
Ascorbic acid	Amla, citrus fruits
Tartaric acid	Tamarind

What is a Base?

Within the chapter Acids bases and salts, we’ll further discuss what is a base. Have you ever tasted baking soda, the one used in cakes? If you have, you know it’s bitter. Substances like detergent, which are bitter and feel soapy to touch, are known as bases. These substances are said to have a basic nature.

Now, since we already know about acids and bases. Let’s explore the different indicators used to test them.

Indicators

Within the chapter Acids bases and salts, we’ll further discuss indicators. Indicators are substances used to identify whether a substance is an acid or a base. Solutions of these substances show different colors in acidic, basic, and neutral solutions. Examples include litmus paper, turmeric, and China rose.

There are various natural indicators present around us. Come, let’s explore them only one by one.

Natural Indicators Around Us

Litmus: Extracted from lichens, it is a commonly used indicator that turns red in acidic solutions and blue in basic solutions. It is available as a solution or in strips of red and blue paper.

Turmeric: Another natural indicator that changes color in the presence of a base but not in an acidic solution.

Soap Solution	Turmeric Paste + Basic Solution	Turmeric Paste + Acidic Solution
Rusted red color	No change	No change

China Rose: To prepare this indicator, collect some Chinese rose petals and place them in warm water until the water becomes colored.

Solution	Color Change with China Rose Indicator
Acidic Solution	Magenta
Basic Solution	Green

Let’s observe some experiments to learn more about indicators and their functions.

Experiments and Observations

Within the chapter Acids bases and salts, we’ll now have a look at some experiments and observations about acids bases and salts. Perform the following experiments and record your remarks:

Solution	Litmus Paper Change	Turmeric Powder Change	China Rose Solution Change
Shampoo solution	Red → Blue	Pale yellow → Red	Green
Lemon juice	Blue → Red	No change	Magenta
Soda water	Blue → Red	No change	Magenta
Vinegar	Blue → Red	No change	Magenta
Sodium bicarbonate	Red → Blue	Pale yellow → Red	Green
Sugar	No change	No change	No change
Common salt	No change	No change	No change

Now that we have a good understanding of acids, bases, and indicators in class 7 Science chapter 4, let’s move on to an important concept: acid rain.

Acid Rain

Acid rain contains excess acids formed from carbon dioxide, sulfur dioxide, and nitrogen dioxide in the air, which dissolve in raindrops to create carbonic acid, sulfuric acid, and nitric acid. Acid rain can damage historical monuments, buildings, plants, and animals.

Let’s learn about a very important reaction that takes place between an acid and a base.

Neutralization

When an acidic solution is mixed with a basic solution, they neutralize each other, forming salt and water and releasing heat. This reaction is called neutralization.

Reaction: Acid + Base → Salt + Water + Heat

Neutralization reactions can be seen in various day-to-day phenomena. Let’s understand a few practical examples of neutralization in our lives.

Neutralization in Everyday Life

Indigestion: Antacids like milk of magnesia relieve indigestion.
Ant Sting: Formic acid from ant stings can be neutralized by rubbing a moist baking soda solution on the affected area.
Bee Sting: Honey-bee stings, which inject acid, can be treated with baking soda.
Agriculture: Plants require a specific pH range for growth. Acidic soil is treated with quicklime, slaked lime, or calcium carbonate to lower its acidity.
Nettle Plant Sting: The methanoic acid injected by nettle plants can be neutralized with baking soda.
Factory Wastes: Factory wastes containing acids must be treated before disposal to prevent harm to aquatic life.

Understanding the properties and interactions of acids bases and salts is crucial for both scientific knowledge and practical applications in daily life.

In conclusion, the chapter Acids Bases and Salts for Class 7 Science provides a comprehensive understanding of the fundamental concepts related to acids, bases, and salts. By exploring the tastes of edible substances, identifying common acids and bases, and learning about various indicators, students gain essential insights into these chemical principles. The chapter’s focus on natural indicators, experiments, and real-life applications such as neutralization reactions enriches the learning experience.

Through engaging with the chapter Acids Bases and Salts, students not only prepare for their exams but also acquire knowledge that is applicable in everyday scenarios. From identifying acids and bases in household items to understanding the impact of acid rain and the importance of neutralization in various contexts, the chapter equips students with valuable skills and knowledge.

So, as you navigate through the chapter Acids Bases and Salts, remember that mastering these concepts lays the groundwork for more advanced studies in chemistry and helps in appreciating the chemistry present in our daily lives.

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Heat- Complete Guide For Class 7 Science Chapter 3

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Our learning resources for the chapter, Heat in Science for Class 7th Chapter 3 are designed to ensure that you grasp this concept with clarity and perfection. Whether you’re studying for an upcoming exam or strengthening your concepts, our engaging animated videos, practice questions and notes offer you the best of integrated learning with interesting explanations and examples.

Welcome to our exploration of Heat, a fundamental concept in class 7 science chapter 3. This chapter delves into the nature of heat, how we measure it, and how it transfers from one place to another.

Let’s break it down step-by-step.

Hot Objects vs. Cold Objects

Heat is a form of energy that can make objects hot or cold. But how do we decide if an object is hot or cold?

A visual representation of hot vs cold objects from class 7 science chapter 3 - Heat

How Do We Decide?

The answer is Sense of Touch. We often use our sense of touch to determine if something is hot or cold. However, this method does not provide exact information about the temperature.

Let’s explore more with a simple example:

A: Kept on a burner
B: At room temperature
C: Kept in the fridge

Water in container B is colder than water in A but hotter than water in C. Is the water in B hot or cold?

Answer: To get accurate information, we need to measure the temperature.

Now, let’s explore more about temperature.

Temperature

Temperature provides a precise measure of how hot or cold an object is. It is measured using a thermometer.

Measuring Temperature

Temperature can be measured through thermometers. Let’s learn how we can read a thermometer.

How to Read a Thermometer

Note the temperature difference between the two larger marks.
Count the small divisions between these marks. For example, if there are 5 small marks between two larger ones, one small division represents 0.2°C.

There are different types of thermometers. Let’s look at each one of them closely.

Types of Thermometers

Different thermometers are used for measuring temperature:

Type of Thermometer	Purpose	Range
Clinical Thermometer	Measures body temperature	35°C to 42°C
Laboratory Thermometer	Measures temperature of objects	-10°C to 110°C
Maximum-Minimum Thermometer	Measures max and min temperatures of the environment	Varies by design

Clinical Thermometer

Made up of a Long, narrow glass tube with a mercury thread.
Range: 35°C to 42°C

How to Measure Body Temperature:

Ensure mercury falls below 35°C.
Place the bulb under the tongue.
Wait for one minute.
Remove and read the temperature.

Precautions:

Wash before and after use.
Ensure the mercury level is below 35°C before use.
Read at eye level.
Do not touch the bulb while reading.

Laboratory Thermometer

Made up of: Similar to a clinical thermometer but with a wider range.
Range: -10°C to 110°C

How to Measure Object Temperature:

Keep the bulb fully inside the object.
Hold vertically.
Wait until the mercury stabilizes.
Note the reading.

Precautions:

Wash before and after use.
Keep upright and avoid contact with container surfaces.

Now, moving on to different methods of heat transfer.

Transfer of Heat

Heat always flows from a hotter object to a colder one. This transfer can occur in three ways:

Conduction
Convection
Radiation

Conduction

Heat flows from the hotter end to the colder end in solids. For example, when you heat one end of a metal rod, the heat travels to the other end.

Conductors vs. Insulators

Type	Description	Examples
Conductors	Allow heat to pass through easily	Iron, Aluminum
Insulators	Poor conductors of heat	Plastic, Wood

Convection

Heat transfer in fluids (liquids and gases) due to the movement of molecules.

Example: Sea breeze and land breeze phenomena.

Sea Breeze:

During the day, land heats up faster than the sea.
Hot air over the land rises, and cooler air from the sea replaces it.

Land Breeze:

At night, the land cools faster than the sea.
Cool air from the land moves towards the sea.

Radiation

Heat transfer that does not require a medium.

Example: Heat from the sun reaching Earth.

Objects and Heat Radiation:

Hot objects emit heat.
Cold objects absorb heat.

When heat falls on an object	It may be…
Absorbed	The object gets warmer.
Reflected	The object remains at the same temperature.
Transmitted	Heat passes through the object.

A visual representation of how different objects radiate heat differently

Choosing the Right Clothes

For the summer season the clothes should be:

Light-colored clothes reflect most of the heat.

For the winter season the clothes should be:

Dark-colored clothes absorb more heat.
Woolen clothes trap air and are poor conductors of heat.

Understanding heat and how to measure and manage it is crucial in daily life. By knowing the different types of thermometers, how heat transfers, and how to dress for different seasons, we can better handle the temperature changes around us.

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Nutrition in Animals- Complete Guide For Class 7 Science Chapter 2

Welcome to iPrep, your Learning Super App. Our learning resources for the chapter, Nutrition on Animals in Science for Class 7th chapter 2 are designed to ensure that you grasp this concept with clarity and perfection. Whether you’re studying for an upcoming exam or strengthening your concepts, our engaging animated videos, practice questions and notes offer you the best of integrated learning with interesting explanations and examples.

While plants can create their food through photosynthesis, animals must consume other organisms to meet their nutritional needs. This process is essential for their growth, repair, and overall functioning. Let’s learn more about this in our chapter ‘Nutrition in Animals’.

Why Do Animals Need Food?

Nutrition in animals starts with understanding why animals need food. All organisms, including humans, require food for:

Growth
Repair
Functioning of the body

Components of Food

When it comes to nutrition in animals, there are various components involved. Those various essential components include :

Carbohydrates
Fats
Proteins
Vitamins
Minerals
Roughage

Digestion

Another significant part of nutrition in animals is Digestion. Digestion is the process of breaking down complex food substances into simpler forms so that they can be used by the body. This process is crucial because the food we eat is too complex to be utilized directly.

Different Ways of Taking Food

The chapter nutrition in animals discussed different ways of taking foods. Different organisms have unique ways of obtaining food:

Bees and Hummingbirds: Suck nectar from flowers.
Infants of Humans and Many Mammals: Breast-feed from their mothers.
Snakes (e.g., Python): Swallow whole prey.
Aquatic Animals (e.g., Octopus): Filter food from the surrounding water.

Examples of Feeding

Nutrition in animals also covers various examples of Feeding. These are:

Hummingbird: Sucking nectar from flowers.
Python: Swallowing prey whole.
Octopus: Grabbing floating food in water.
Starfish: Feeding on hard-shelled animals by eviscerating its stomach into the shell.

The Human Digestive System

When understanding nutrition in Animals, it is important to understand the human Digestive system. The human digestive system is a complex network designed to break down food and absorb nutrients.

Alimentary Canal

The alimentary canal is a tube running from the mouth to the anus and includes the following parts:

Buccal Cavity
Food Pipe (Oesophagus)
Stomach
Small Intestine
Large Intestine
Rectum
Anus

Mouth and Buccal Cavity

The chapter Nutrition in Animals further covers the Mouth and Buccal Cavity which involves.

Ingestion: The process of taking food into the mouth.
Teeth: Break down food into smaller particles. Types of teeth:
- Incisors: Biting and cutting.
- Canines: Gripping and tearing.
- Premolars: Chopping and grinding.
- Molars: Grinding and crushing.

A visual representation of the Mouth and Buccal Cavity Form class 7 Science Chapter 2- Nutrition In Animals

Salivary Glands: Secrete saliva that begins the digestion of carbohydrates.
Tongue: Helps mix, taste, and swallow food.

We can conclude that:

Food is taken into the body through the mouth.
The process of taking food into the body is called ingestion.
Teeth present in the mouth break down the food into smaller particles and help in mixing them mechanically.
Salivary glands secrete saliva which helps in converting complex sugar into simple sugar.
The tongue helps in mixing, tasting, and swallowing food.

Activity: Testing the Effect of Saliva

Let’s now do an activity to better understand the concept of nutrition in animals.

Test Tubes Preparation:
- Test Tube A: Boiled rice.
- Test Tube B: Boiled rice chewed for 3-5 minutes.
- Add iodine solution to both and observe.
Result: Test Tube A turns blue/purple; Test Tube B does not change color, indicating the breakdown of starch into sugars by saliva.

A visual representation of the TESTING THE EFFECT OF SALIVA Form class 7 Science Chapter 2- Nutrition In Animals

Position of taste buds on the tongue

A visual representation of the positions of taste buds on tongue Form class 7 Science Chapter 2- Nutrition In Animals

Different taste buds detect different tastes of food.

Activity to check the taste buds

1. Prepare samples for each of:

i) Sugar solution

ii) Common salt solution

iii) Lemon juice

iv) Juice of crushed neem leaf or something bitter like bitter gourd.

2. Blindfold one of your class friends and ask him/her to take out the tongue and keep it in a flat position.

3. Take fresh toothpicks to put the different samples on his/her tongue. Use a new toothpick for each sample.

4. Observation: Ask the friend to point out which area is tasting which taste on the tongue as shown in the figure above.

Digestion in the Alimentary Canal

Oesophagus: Transports food to the stomach via peristalsis (wave-like muscle contractions).

The swallowed food moves through the esophagus by peristalsis. This runs along the neck and chest.
Food is pushed down by movement of the wall of the food pipe. Such movements by the wall of the alimentary canal to push the food in the forward direction, are called peristalsis.
Sometimes the food is not accepted by the walls of the alimentary canal and is vomited out.
HCl from the stomach kills many bacteria coming along with the food. It also provides the acidic medium to the stomach required for the chemical reactions.
The digestive juices break down the proteins into simpler components.
The mucous protects the lining of the wall of the stomach.

Stomach

Thick-walled muscular bag.
Secretes HCl, mucous, and digestive juices.
Begins the breakdown of proteins.

Small Intestine

Length: About 7.5 meters.
Functions:
- Receives bile from the liver and pancreatic juice from the pancreas.
- Completes digestion of carbohydrates, proteins, and fats.
Absorption: Nutrients are absorbed through villi into the bloodstream.
Liver: a reddish brown gland situated in the upper part of the abdomen on the right side. It secretes bile juice, which helps in the breakdown of fats. Bile is stored in a sac-like structure called the gallbladder.
Pancreas: a large creamy-coloured gland located just below the stomach. It secretes pancreatic juice, which acts on carbohydrates and proteins to convert in simpler forms.
The partly digested food reaches the lower part of the small intestine, where the intestinal juice completes the digestion of all digestible components.

A visual representation of complete digestion of food by the action of different juices Form class 7 Science Chapter 2- Nutrition In Animals

A visual representation of the Human intestine System Form class 7 Science Chapter 2- Nutrition In Animals

Absorption of Digested Food

Absorption occurs in the small intestine with the help of villi, which increases the surface area for absorption.
The absorbed nutrients are transported via blood vessels to different body organs, where assimilation occurs.

Large Intestine

Length: About 1.5 meters.
Functions:
- Absorbs water and salts.
- The waste in the form of semi-solid remains in the rectum. This waste in the form of feces is removed through the anus.
- This process of removal is called egestion.

The entire digestion process looks like this:

Mouth (Ingestion) –> Oesophagus (Peristalsis) –> Stomach (HCl and digestive juices) –> Small Intestine (Pancreatic and bile juices) –> Absorption in Villi –> Large Intestine (Water absorption) –> Rectum (Waste storage) –> Anus (Egestion)

Summary Table of Digestive Juices and Their Actions

Digestive Juice	Source	Action
Saliva	Salivary glands	Converts complex sugars into simple sugars
Bile	Liver	Breaks down fats into smaller fat globules
Pancreatic juice	Pancreas	Acts on carbohydrates and proteins
Intestinal juice	Small intestine	Completes the digestion of all digestible components

Unique Digestion in Grass-Eating Animals

Rumination in Ruminants

The chapter nutrition in animals also covers Rumination. Ruminants like cows and buffaloes have a rumen, where partially digested food (cud) is stored and later chewed.

They have a sac-like structure between the small and large intestines for digesting cellulose with the help of microbes. Therefore, to summarize-

Rumen: A special stomach chamber where the grass is partially digested.
Cud: The regurgitated and re-chewed food.
Process: Cud returns to the mouth for further chewing.
In this sac, the cellulose of the food is digested by the action of microbes present in cattle. Such microbes or bacteria are not found in human beings. This is why humans are not able to digest the cellulose of the food.

Amoeba

Nutrition in animals also covers, nutrition in Amoeba.

Amoeba is a microscopic unicellular organism found in pond water.
Its single-celled body is covered by a cell membrane.
Inside the cytoplasm, there is a round nucleus and many bubble-like sacs called vacuoles.
It can change its body shape by forming pseudopodia, which are a kind of false foot in the form of finger-like projections. These pseudopodia help the amoeba in taking up food and changing its position.

Feeding in Amoeba

Amoeba is a single-celled organism with unique feeding methods:

Amoeba feeds on microscopic bits of food from its surroundings.
Whenever it senses the food, it stretches out its pseudopodia around the food, like a cup.
Food is engulfed in a food vacuole.
Once the food is in a food vacuole, the digestive juices are secreted. These juices break down the complex molecules into simpler ones.
The broken and simplified food in the body of the amoeba is absorbed.
The absorbed food in the cytoplasm is utilized for growth, maintenance, and multiplication.
The absorbed food on oxidation in the cytoplasm releases energy for the movement of the body and other activities.
The vacuole also helps in expelling out the undigested food.

A Visual representation of feeding in Amoeba rom class 7 science chapter 2 - Nutrition In Animals

In conclusion, Class 7 Science Chapter 2 – Nutrition in Animals provides a comprehensive understanding of how animals, including humans, obtain, process, and utilize food for their survival. From the breakdown of complex food substances in the digestive system to the unique feeding habits of different organisms like amoeba and ruminants, this chapter covers essential concepts that highlight the diversity of nutritional strategies in the animal kingdom.

The study of Nutrition in Animals not only deepens our understanding of biological processes but also underscores the vital role of nutrition in maintaining life. By mastering the content of Class 7 Science Chapter 2 – Nutrition in Animals, students are well-equipped to appreciate the intricacies of animal biology and apply this knowledge in their academic journey. Remember, Nutrition in Animals is a key concept that lays the foundation for future studies in biology, making this chapter crucial for building a strong scientific understanding.

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Nutrition In Plants – Complete Guide For Class 7 Science Chapter 1

Welcome to iPrep, your Learning Super App. Our learning resources for the chapter, Nutrition on Plants in Science for Class 7th are designed to ensure that you grasp this concept with clarity and perfection. Whether you’re studying for an upcoming exam or strengthening your concepts, our engaging animated videos, practice questions and notes offer you the best of integrated learning with interesting explanations and examples.

The chapter Nutrition in Plants of class 7 Science is a fundamental topic in understanding how plants grow, develop, and contribute to our environment. This chapter covers the essential nutrients that plants need, how they obtain these nutrients, and various modes of nutrition.

Let’s start with understanding What are nutrients?

Nutrients

In the chapter Nutrition in Plants, there is a significant mention of the concept Of Nutrients. Nutrients are crucial for providing energy, building and maintaining body organs, and supporting various metabolic processes in organisms. For plants, the essential nutrients include:

Carbohydrates
Proteins
Fats
Vitamins

Essential Plant Nutrients

When it comes to Nutrition in Plants, they require specific nutrients to complete their life cycle. Not all nutrients are essential, but they can still benefit from some non-essential nutrients like Sodium (Na) and Silicon (Si).

Nutrition

Nutrition is the process by which organisms obtain and use nutrients for maintaining life. When it comes to Nutrition in plants, there are two primary types of nutrition:

Autotrophic Nutrition
Heterotrophic Nutrition

Autotrophic Nutrition

Autotrophic nutrition involves the formation of food by using simple inorganic substances. Organisms that perform autotrophic nutrition are known as autotrophs, with green plants being prime examples. They carry out this process through photosynthesis.

Autotrophs

Green Plants: These organisms create their food through photosynthesis.

Heterotrophic Nutrition

Heterotrophic nutrition relies on other organisms or dead organic matter for food. Organisms that cannot produce their own food are called heterotrophs. Examples include animals and protozoa like amoeba and paramecium.

Heterotrophs

Animals
Protozoa: e.g., Amoeba, Paramecium

Modes of Nutrition

Different organisms have distinct ways of obtaining and utilizing nutrients:

Mode of Nutrition	Description	Examples
Parasitic	Relies on host plants for nutrients	Cuscuta (Dodder)
Insectivorous	Consumes insects for nutrients	Pitcher Plant
Saprotrophic	Obtains nutrients from dead and decaying matter	Fungi, Bacteria
Symbiotic	Mutualistic relationship with another organism	Lichens

Cells

According to the chapter Nutrition In Plants, all living organisms are made up of cells. Cells are tiny structures that can only be seen under a microscope.

The cell is a small structure that is surrounded by a thin boundary cell membrane. The nucleus is the most conspicuous organelle found in the center of the cell. It houses the cell’s chromosomes and is the place where almost all the processes for the transfer of genetic information occur. The nucleus is surrounded by cytoplasm which is a gelatinous fluid that fills most cells. A nucleus is kept separate from the cytoplasm by a double membrane layer – nuclear membrane.

a visual representation of cells, from class 7 science chapter 1 - Nutrition in Plants

Types of Cells

Unicellular: Single-celled organisms (e.g., Amoeba, Paramecium)
Multicellular: Organisms with multiple cells (e.g., Plants, Animals)

Photosynthesis

The chapter Nutrition in Plants very significant covers the concept of Photosynthesis. Photosynthesis is the process by which plants make their own food using sunlight, carbon dioxide, and water. Basically it is the process that creates the source of nutrition in plants.

Carbon dioxide from the air is taken through the tiny pores present on the surface of the leaves.
These pores are surrounded by guard cells which regulate the exchange of carbon dioxide.
These pores are called stomata.

a visual representation of parts of plants responsible for photosynthesis from class 7 science chapter 1 - Nutrition in Plants

Photosynthesis Equation

The image given below clearly showcases the equation of photosynthesis, a crucial part of Nutrition in Plants.

Transportation of Minerals

Another form of Nutrition in plants is called transportation of Minerals. Minerals and water are absorbed by plant roots and transported to the leaves via vessels. These vessels create a continuous pathway for nutrient movement.

Pigments

Chlorophyll: The green pigment in plants that captures light energy for photosynthesis. Found in chloroplasts.

Other Pigments: Red, brown, and other pigments can mask chlorophyll but still participate in photosynthesis.

Synthesis of Different Foods

Plants synthesize carbohydrates, fats, and proteins. Nitrogen, essential for protein synthesis, is converted into a soluble form by soil bacteria through nitrogen fixation.

Nitrogen Fixation

Bacteria in the soil convert atmospheric nitrogen into a form that plants can absorb and use.

a visual representation of Synthesis of Different Foods, from class 7 science chapter 1 - Nutrition in Plants

Different Modes of Nutrition in Plants

Parasitic Plants: Obtain nutrients from host plants. Example: Cuscuta
Insectivorous Plants: Capture and digest insects for nutrients. Example: Pitcher Plant
Saprotrophs: Decompose dead organic matter. Examples: Fungi, Bacteria
Symbiosis: Mutual benefit between two organisms. Example: Lichens

Parasitic Plants

Heterotrophic Nutrition

Some plants depend on other plants for their food sources- The organism Heterotrophs.
They cannot make their own food because they do not have chlorophyll.
Ingest and oxidize carbohydrates, fats, and proteins synthesized by autotrophs.

Autotrophic Nutrition

Parasitic Plants

They lack chlorophyll
Rely on the host plant for water and all nutrients.
The parasite gains nutrition and in this process, it harms the host plant. Example: Cuscuta (Amerbel)
Cuscuta is a yellow tubular plant twining around the stem and branches of a tree.
It does not have chlorophyll. It takes ready-made food from the host plant on which it is climbing.

Insectivorous Plants

Just like many animal species, some plant species are carnivorous—that is, they consume insects and other small animals as a primary source of nutrients and minerals for growth.
Instead of actually eating insects, carnivorous plants trap them by various means, depending on the kind of plant.
These grow in nutrient-poor habitats.
The ability of carnivorous plants to capture and digest insects, is supplemented by their capacity to make energy stores by photosynthesis as other green plants do. Example – Pitcher plant.
In this plant, the pitcher-like structure is the modified part of the leaf.
The apex of the leaf forms a lid that can open and close the mouth of the pitcher.
Inside the pitcher, there are hair which are directed downwards. When an insect lands in the pitcher, the lid closes and the trapped insect gets entangled into the hair.
The insect is digested by the digestive juices secreted in the pitcher.

Saprotrophs

An organism that obtains its nutrients from non-living organic matter, usually dead and decaying plant or animal matter, by absorbing soluble organic compounds. Example: fungi, bacteria.
They secrete digestive juices on the dead and decaying matter and convert it into a solution. Then they absorb nutrients from it. This is called saprotrophic nutrition.
Saprotrophs
As decomposers, they allow essential materials (e.g. C, N) to be recycled in the ecosystem.

Fungi also grow on pickles, leather, clothes and other articles that are left in hot and humid weather for a long time. During the rainy season, they spoil many things.

Symbiotic Relationships

The intimate association between two distantly, related species that are mutually benefiting from this association. For example – certain fungi live in the roots of the trees.
Fungi enhance mineral transport to plants, especially phosphorous.
The tree provides nutrients to the fungus.
Plants with fungi are more drought-resistant.
Plants with fungi are more resistant to plant pathogens.

Lichens: A partnership between fungi and algae. Fungi provide shelter and minerals, while algae provide food through photosynthesis.

Let’s summarize the mode of nutrition in a flow chart:

Mode of Nutrition	Description	Examples
Parasitic	Relies on host plants for nutrients	Cuscuta (Dodder)
Insectivorous	Consumes insects for nutrients	Pitcher Plant
Saprotrophic	Obtains nutrients from dead and decaying matter	Fungi, Bacteria
Symbiotic	Mutualistic relationship with another organism	Lichens

Replenishment of Nutrients in Soil

To maintain soil fertility, nutrients must be replenished through fertilizers, manures, and biological means like nitrogen fixation.

Rhizobium in Legume Plants

Rhizobium bacteria form a symbiotic relationship with legume plants to convert atmospheric nitrogen into a form usable by plants. In return, the plants provide food and shelter for the bacteria.

This blog provides a comprehensive overview of Nutrition in Plants, helping students grasp fundamental concepts and appreciate the complexity of plant life.

In conclusion, Class 7 Science Chapter 1 – Nutrition in Plants is essential for understanding how plants sustain themselves and contribute to the environment. By exploring the different modes of nutrition such as autotrophic, heterotrophic, and symbiotic relationships, this chapter provides a solid foundation for students to grasp the intricacies of plant biology. The concept of Nutrition in Plants not only highlights the importance of nutrients for plant growth but also underscores the interconnectedness of various life forms in an ecosystem. Through this chapter, students will gain valuable insights into the vital processes that support life on Earth, making Nutrition in Plants a cornerstone of their scientific education.

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Transportation in Plants and Animals- Complete Guide For Class 7th Science Chapter 7

Understanding Transportation In Plants And Animals

Transportation in Humans

The Circulatory System

Components of the Circulatory System

Blood Composition

Table of Blood Components

Blood Vessels

Comparison of Blood Vessels

The Heart

Diagram of the Human Heart

Heart Chambers in Various Animals:

Heartbeat

Lymph

Formation of Lymph

Circulation

Flowchart of Blood Circulation

Excretion

The Process of Excretion

The Human Excretory System

Filtration and Urine Formation

Flowchart of Urine Formation

[Blood] -> [Kidneys] -> [Urine Formation] -> [Ureters] -> [Bladder] -> [Urethra]

Excretion in Other Animals

Dialysis

Excretion in Plants

Transportation in Plants

Need for Transportation

Transport of Water and Minerals

Flowchart of Water Movement in Plants

Transport of Food (Translocation)

Flowchart of Food Transport

[Leaves] <-> [Phloem] <-> [Other Parts]

Conclusion

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Respiration in Organisms- Complete Guide For Class 7th Science Chapter 6

Cellular Functions and Energy

What is Respiration in Organisms?

Steps of Respiration in Organisms

Types of Cellular Respiration

Aerobic Respiration

Anaerobic Respiration

Breathing

Mechanism

Role of the Diaphragm and Rib Cage In Breathing

Mechanism of Breathing

Smoking

Breathing in Animals

Insects

Earthworms

Frogs

Breathing Underwater

Breathing in Plants

Plant Respiration Formula

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Chapter 6 - Respiration In Organisms

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Acids Bases and Salts- Complete Guide For Class 7 Science Chapter 4

Tastes of Edible Substances

What is an Acid?

Common Acids in Substances

What is a Base?

Indicators

Natural Indicators Around Us

Experiments and Observations

Acid Rain

Neutralization

Neutralization in Everyday Life

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