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NCERT Class 7 Science Chapter 7 is a gateway to the circulatory system of the human body. While understanding the circulatory system, we learn about blood and its components and the heart. When understanding these body parts, we explore the transportation of oxygen, nutrition, and waste products in human beings. In addition, this chapter also explains the transportation of water and nutrition in plants. All these elements have been craftfully explained in our CBSE Class 7 Science notes. Keep browsing through the notes to revise the chapter on Transportation in Animals and Plants.
Download NCERT Science Class 7 Science Chapter 7 Important Questions and Answers PDF
Explore all the Chapters of Class 7 Science:
| Chapter 1 | Chapter 2 | Chapter 3 | Chapter 4 | Chapter 5 | Chapter 6 |
| Chapter 7 | Chapter 8 | Chapter 9 | Chapter 10 | Chapter 11 | Chapter 12 |
| Chapter 13 |
Table of Contents
Circulatory System
In this introductory section of the NCERT Class 7 Science Chapter 7, we will learn about blood and its components, blood vessels, and the heart and its components. Let us begin!!
Blood
Blood is a red fluid in our body that carries oxygen from the lungs to our cells. Also, it transports digested food from small intestine to other body parts. In addition, it is also responsible for transporting wastes that need to be removed from the body.
Components of Blood
Here are the different components of blood:
- Plasma: It is a fluid in which several kinds of cells are present.
- Red Blood Cells (RBC): This cell type is suspended in plasma which contains “haemoglobin”. Haemoglobin is a red pigment that binds with oxygen (O2) to transport O2 to all the cells of the body. Also, blood appears red due to the presence of haemoglobin.
- White Blood Cells (WBC): These cells in the blood help us fight against germs and improve our immunity.
- Platelets: It is also a cell in our blood. The presence of platelets facilitates blood clots when we get hurt or experience a cut.
Blood Vessels
The human body has two types of blood vessels, which are:
- Arteries: Arteries transport oxygenated blood from the heart to every area of the body. Because the blood flow is fast and under significant pressure, arteries possess sturdy and flexible walls.
- Veins: Veins are responsible for transporting carbon dioxide-rich blood from various parts of the body back to the heart. Unlike arteries, veins have thinner walls. Valves are also found within veins. These valves ensure that blood flows in one direction, specifically toward the heart.
Capillaries
When arteries reach the tissues, they are classified into very thin tubes known as “capillaries”. These tubes join together to form veins that empty inside our hearts.
Heart
The heart is an essential organ in our body which is present in our chest cavity. This organ beats constantly to pump blood to each and every cell of our body.
Now, let us know about the different parts of the Human Heart:
- Atria and Ventricles: The human heart is divided into four chambers. The upper two chambers are the “Right Atrium” and “Left Atrium”. Whereas, the lower chambers are the “Right Ventricle” and “Left Ventricle”.
- A muscular partition: It is a horizontal partition that separates the right side of the heart from that of the left. This part of the heart prevents the mixing of oxygen-rich blood with carbon dioxide-rich blood.
- Pulmonary Artery: This tube-like structure is a road in your body that carries “used” blood from your heart to your lungs, so it can get fresh oxygen.
- Pulmonary Vein: It is another road that brings the “fresh” oxygenated blood from your lungs back to your heart.
- Aorta: The biggest tube in the heart that takes the fresh, oxygen-rich blood from your heart to your entire body.
- Vena Cava: This tube brings the “used” blood from your body back to your heart, so it can be refreshed.
Excretion in Animals
Furthermore, in this part of our NCERT Class 7 Science Chapter 7 notes on Transportation in Animals and Plants, we learn about excretion in animals and the human excretory system. To simplify learning, we have included some graphics and videos. Use them to make learning fun!!
Excretion and Excretory System
- Excretion: It refers to the process of waste removal from living organisms. The waste is produced in our body cells and carried through blood to our anus.
- Excretory System: The body parts engaged in the excretion of waste from living organisms are known as the excretory system.
Excretory System in Humans
Now, let us explore different parts of the human excretory system. Also, we will simultaneously understand the process of excretion in humans:
- Kidneys: A human body has a “pair of kidneys” where excretion starts. As we know, the body needs to get rid of waste in the blood. Thus, it uses a filtering system. This job is done through Kidney blood capillaries. When blood reaches the Kidneys, it has useful substances and waste materials. The useful substances go back into the blood, and the waste in water becomes urine.
- Ureters: Thereafter, urine from the kidney is transported to the next part of the excretory system via two tubes known as “ureters”.
- Urinary Bladder: This part of the excretory system stores urine generated by the kidney. Urine from the kidney travels to the “urinary bladder” through the ureters.
- Urethra: Urine is held in the bladder and comes out through a muscular tube called the “urethra”, which has an opening for this purpose.
| Did You Know? A typical adult person usually releases around 1 to 1.8 litres of urine in a day. This urine is mostly water (about 95%), with about 2.5% being urea and another 2.5% being various other waste materials. |
| Dialysis In some cases, a person’s kidneys can stop working because of infection or injury. When this happens, waste products build up in their blood. These people cannot stay healthy unless their blood is cleaned regularly with the help of a machine called an artificial kidney, and this cleaning process is known as “dialysis”. |
Transport of Substances in Plants
This part of the NCERT Class 7 Science Chapter 7 is an extension to Class 7 Science Chapter 1. In Chapter 1 we learnt about photosynthesis. Now, in chapter 7 we will explore the transport of water and minerals in plants and transpiration. Let’s proceed!!
Transport of Water and Nutrients: Xylem
Plants take in water and minerals through their roots, which have tiny structures called root hairs. These root hairs help by expanding the surface area of the root, making it easier for the plant to soak up water and the nutrients dissolved in it. The root hairs come into contact with the water found between soil particles and absorb it. Water and nutrients absorbed through the roots are then transported to the parts of plants through the “xylem”.
What is Xylem?
Plants use pipe-like vessels made of special cells called the “xylem” to move water and nutrients from the soil. The xylem is a part of the plant’s vascular tissue, which is like a group of cells that have a specific job. The xylem creates a network of channels that link the roots to the leaves through the stem and branches, ensuring water is carried throughout the entire plant.
Transport of Food: Phloem
Leaves make food, and this food needs to go to all parts of the plant. This job is carried out by another part of the plant’s vascular tissue called the “phloem”.
Transpiration
The process of water loss in plants through leaves is known as “transpiration.”
Plants take in minerals and water from the soil, but they don’t use all the water they absorb. Some of it evaporates through tiny openings on leaf surfaces called stomata, a process known as transpiration. This evaporation creates a sort of suction, similar to when you suck liquid through a straw, which can help draw water up to great heights in tall trees. Transpiration also has the added benefit of cooling the plant.
Explore all the Chapters of Class 7 Science:
| Chapter 1 | Chapter 2 | Chapter 3 | Chapter 4 | Chapter 5 | Chapter 6 |
| Chapter 7 | Chapter 8 | Chapter 9 | Chapter 10 | Chapter 11 | Chapter 12 |
| Chapter 13 |
NCERT Solutions Class 7 Science Chapter 7: Transportation in Animals and Plants
Furthermore, let us view at answers to questions in the NCERT Class 7 Science Chapter 7 on Transportation in Animals and Plants.
Ques 1. Match structures given in Column I with functions given in Column II.
| Column I | Column II |
| (i) Stomata | a. Absorption of water |
| (ii) Xylem | b. Transpiration |
| (iii) Root hairs | c. Transport of food |
| (iv) Phloem | d. Transport of water |
| e. Synthesis of carbohydrates |
Ans:
| Column I | Column II |
| (i) Stomata | b. Transpiration |
| (ii) Xylem | d. Transport of water |
| (iii) Root hairs | a. Absorption of water |
| (iv) Phloem | c. Transport of food |
Ques 2. Fill in the blanks.
(i) The blood from the heart is transported to all parts of the body by the______________.
(ii) Haemoglobin is present in_________________ cells.
(iii) Arteries and veins are joined by a network of____________________.
(iv) The rhythmic expansion and contraction of the heart is called____________________.
(v) The main excretory product in human beings is_________________.
(vi) Sweat contains water and___________________.
(vii) Kidneys eliminate the waste materials in the liquid form called_________________.
(viii) Water reaches great heights in the trees because of suction pull caused by___________.
Ans:
(i) Arteries
(ii) Red Blood Cells
(iii) Capillaries
(iv) Heartbeat
(v) Urea
(vi) Salt
(vii) Transpiration
Ques 3. Choose the correct option:
a. In plants, water is transported through
(i) xylem
(ii) phloem
(iii) stomata
(iv) root hair
Ans: Option (i) Xylem
b. Water absorption through roots can be increased by keeping the plants:
(i) in the shade
(ii) in dim light
(iii) under the fan
(iv) covered with a polythene bag
Ans: Option (iii) Under the fan
Ques 4. Why is the transport of materials necessary in a plant or in an animal? Explain.
Ans: The transport of materials, such as nutrients and oxygen, is vital for the survival of both plants and animals. Without this transportation system, these essential substances would not reach all parts of the body. Owing to this, the human body or plant would not be able to survive and function properly. It is like the delivery system that ensures everything the body or plant needs gets to where it is required.
Ques 5. What will happen if there are no platelets in the blood?
Ans: Lack of platelets in the blood will result in constant blood loss after injury because platelets are responsible for blood clots.
Ques 6. What are stomata? Give two functions of stomata.
Ans: Minute openings on the surface of leaves are known as stomata.
Here are two important functions of stomats:
- They enable the exchange of gases.
- Also, stomata helps in transpiration.
Ques 7. Does transpiration serve any useful function in the plants? Explain.
Ans: Here are some reasons why transpiration is useful for plants:
- It boosts the uptake of water and minerals by generating a suction force.
- It aids in eliminating surplus water.
- It assists in moving water and minerals to the leaves, where water is utilized for photosynthesis.
- It creates a cooling impact on the plant.
Ques 8. What are the components of blood?
Ans: Here are the various components of blood:
- Plasma
- Red Blood Cells
- White Blood Cells
- Platelets
Ques 9. Why is blood needed by all the parts of a body?
Ans: All parts of the body require blood because it carries digested food and oxygen. Blood delivers oxygen and nutrients to different body parts, thereby, providing the energy needed for various bodily functions.
Ques 10. What makes the blood look red?
Ans: The presence of haemoglobin in RBCs makes blood look red. Haemoglobin is a red pigment present in the plasma of the blood.
Ques 11. Describe the function of the heart.
Ans: The heart is a tirelessly beating organ that serves as a pump to move blood, carrying various substances. It comprises four chambers: two upper ones, called atria, and two lower ones, called ventricles. The divisions between these chambers prevent the mixing of oxygen-rich and carbon dioxide-rich blood. Blood travels from the heart to the lungs and back before the heart pumps it to the body’s other parts.
Ques 12. Why is it necessary to excrete waste products?
Ans: As waste products are primarily made of toxic materials like urea, it is essential to excrete them. Accumulation of waste products makes us unhealthy.
FAQs
Q 1. What is dialysis?
Ans: When a person’s kidneys stop working because of infection or injury waste products build up in their blood. These people cannot stay healthy unless their blood is cleaned regularly with the help of a machine called an artificial kidney, and this cleaning process is known as “dialysis”.
Q 2. What is blood?
Ans: Blood is a red fluid in our body that carries oxygen from the lungs to our cells. Also, it transports digested food from small intestine to other body parts. In addition, it is also responsible for transporting wastes that need to be removed from the body.
Q 3. What is transpiration?
Ans: The process of water loss in plants through leaves is known as “transpiration.”
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