Class 7 – Science- Chapter 11-Transportation in Animals and Plants question answer (Long Question Answer)

Chapter 11- Transportation in Animals and Plants -Long Questions and Answers (Solved Worksheet)

Question 1- How does the composition of blood contribute to its various functions such as transportation of oxygen, nutrients, and protection from diseases?

Answer- The blood is a vital fluid flowing through the blood vessels, ensuring that every part of the body functions efficiently. The main components of blood are plasma, Red Blood Cells (RBCs), White Blood Cells (WBCs), and platelets. Each of these plays a unique role in supporting bodily functions.

• RBCs contain haemoglobin, a red pigment that is specialised in binding and transporting oxygen from the lungs to various parts of the body. Haemoglobin is the reason behind the red appearance of the blood and is essential for ensuring that all body cells receive adequate oxygen for metabolic processes.
• WBCs are the body’s defence warriors. They play a crucial role in immunological functions as they fight against germs and foreign substances that enter the body, ensuring that the body remains healthy and protected from infections.
• Platelets are essential for clotting. Whenever there’s an injury or a cut, platelets help form a clot at the wound site, preventing excessive bleeding and facilitating the healing process by preventing the entry of foreign particles and bacteria.

Also Check- NCERT Exemplar Solutions- Class 7 Science Chapter – 11-Transportation in Animals and Plants

Question 2- What is the role of haemoglobin in the circulatory system, and why is it vital for the red blood cells?

Answer- Haemoglobin is a red protein responsible for transporting oxygen in the blood. It is located within the Red Blood Cells (RBCs) and has a high affinity for oxygen. The primary role of haemoglobin is to pick up oxygen from the lungs and deliver it to the different body cells, ensuring that cellular metabolic activities can proceed efficiently.

Haemoglobin is essential for the RBCs because it fundamentally defines their role in the circulatory system. RBCs, filled with haemoglobin, specialise in oxygen transportation, ensuring that every part of the body receives a sufficient oxygen supply for optimal functioning. Haemoglobin also assists in collecting carbon dioxide, a waste product from cell metabolism, transporting it back to the lungs for removal from the body. Without haemoglobin, RBCs wouldn’t be equipped to perform these essential transportation functions effectively.

Also Check – Rapid Revision – Class 7 Science- Chapter 11- Transportation in Animals and Plants

Question 3- Describe the Structure and Function of Arteries in the Human Circulatory System.

Answer-

Structure of Arteries-

• Robust and Elastic- Arteries are well-structured, robust, and elastic vessels. This unique construction allows them to handle the high pressure of blood pumped directly from the heart.
• Muscular and Thick Walls- The walls of arteries are muscular and thick, attributes necessary for maintaining the high-speed and forceful flow of oxygen-rich blood.

Function of Arteries-

• Circulation- Arteries act as the main conduits of the circulatory system. Originating from the heart, they transport oxygen-saturated blood to various parts of the body.
• Branching and Extensive Reach- As arteries diverge further from the heart, they branch into smaller vessels, extending the reach of oxygenated blood to nourish every cell, fostering optimal body functionality and health.

Question 4- What Makes the Pulmonary Artery and Vein Exceptional Compared to Other Blood Vessels?

Answer-

Pulmonary Artery-

• Unique Role– Contrary to typical arteries, the pulmonary artery carries blood rich in carbon dioxide and low in oxygen. Originating from the heart, it transports this blood to the lungs for oxygenation.
• Reason for Classification- It is classified as an artery not because of the type of blood it carries, but due to its origin from the heart.

Pulmonary Vein-

• Exceptional Function- Unlike other veins, the pulmonary vein transports oxygen-rich blood. It channels this oxygen-saturated blood from the lungs back to the heart, sustaining the oxygen supply essential for body tissues and overall physiological equilibrium.

Question 5- Explain the Significance of Capillaries in the Exchange of Substances within the Body.

Answer-

Formation and Structure-

• Thin-Walled Vessels- Capillaries stand as the thinnest and smallest vessels in the circulatory system. With walls just one cell thick, they facilitate a proficient exchange of substances.

Role in Substance Exchange-

• Embedded in Tissues- Capillaries pervade body tissues, permitting a close and effective exchange of oxygen, nutrients, and waste materials between the blood and body cells.
• Extensive Network- Through their widespread network, capillaries maximise the exchange surface area. This strategic design ensures that each cell obtains the essential nutrients and oxygen while efficiently expelling waste, promoting overall cellular health and body functionality.

Question 6- Describe the process of blood circulation, emphasising the role of the heart, arteries, veins, and capillaries.

Answer-

The process of blood circulation is vital for the sustenance and functioning of the human body. It primarily involves the following stages-

• Oxygen Transport- The heart plays a pivotal role as it pumps freshly oxygenated blood into the arteries. These arteries, being robust and extensive, then branch out to deliver oxygen to every cell in the body.
• Carbon Dioxide and Waste Removal- After the oxygen delivery, the blood becomes deoxygenated and rich in waste products. The veins collect this blood and channel it back to the heart. Subsequently, the heart pumps this blood to the lungs for purification and removal of carbon dioxide.
• Capillary Exchange- Capillaries are the tiny blood vessels that facilitate the exchange of materials. Through the thin walls of the capillaries, oxygen and nutrients pass from the blood to the body’s cells. Simultaneously, waste products move from the cells into the blood, ready to be expelled from the body.
• Cycle Continuation- This entire process is perpetual. It ensures a constant delivery of essential nutrients and oxygen to the cells and simultaneously ensures the removal of waste products. This keeps the body alive and functioning optimally.

The heart is central to this process. Positioned in the chest cavity and slightly towards the left, it functions as a powerful pump. It has four distinct chambers- the atria (upper) and the ventricles (lower). The atria receive blood returning to the heart, while the ventricles pump blood out of the heart. The heart’s meticulous organisation ensures a unidirectional flow of blood, maintaining a clear distinction between oxygen-rich and carbon dioxide-rich blood.

Question 7-  Explain the significance and characteristics of the pulse and pulse rate in relation to the circulatory system.

Answer-

The pulse is a critical indicator of heart activity and the circulatory system’s efficiency. It can be defined as the rhythmic throbbing or vibration felt in various body parts, especially on the wrist, due to blood flow through arteries. This sensation originates directly from the heart’s contractions as it pushes blood into the arteries.

The significance of the pulse lies in its ability to provide tangible evidence of the heart’s activity. It indicates the heart’s beating rate, which is essential for medical evaluations.

Pulse rate, defined as the number of heartbeats or pulses felt in one minute, typically ranges between 72 and 80 beats per minute for a resting individual. However, this rate can vary depending on factors like age, health, activity level, and more.

Question 8- Elaborate on the heart’s structure, its chambers, and their specific roles in the blood circulation process.

Answer-

The heart, located in the chest cavity and slightly tilted to the left, is comparable in size to a closed fist. This muscular organ operates tirelessly, ensuring effective blood circulation.

The heart is divided into four chambers to prevent the mingling of oxygen-rich blood with carbon dioxide-laden blood. These chambers include-

• Atria- The upper two compartments are the atria. Their primary function is to receive blood returning to the heart from various body parts.
• Ventricles- The lower two compartments, ventricles, are responsible for pumping blood out of the heart to different body regions.

Precise partitioning in the heart, facilitated by walls called septa, ensures that oxygen-rich and carbon dioxide-rich blood does not mix. This distinction is crucial as it guarantees a consistent supply of oxygenated blood to the body.

The blood flow direction within the heart is very organised. Starting from the heart’s right side, the blood moves towards the lungs, gets oxygenated, then returns to the left side of the heart, and is subsequently propelled into the rest of the body.

The left side of the heart deals exclusively with oxygen-rich blood. Once oxygenated in the lungs, the blood returns to the heart, where it’s received by the left atrium. This blood then transfers to the left ventricle, which pumps it out to cater to various body parts. In contrast, the heart’s right side manages carbon dioxide-rich blood. This deoxygenated blood, received from the body, is then routed to the lungs for oxygenation.

Question 9- Describe the sequential functioning of the heart in the circulatory system and its significance for effective circulation.

Answer- The heart, a central component of the circulatory system, functions in a well-orchestrated sequence ensuring efficient blood circulation.

• Sequential Pumping- The heart’s operation begins with the atria. The right atrium collects deoxygenated blood coming from the body, while the left atrium gathers oxygenated blood returning from the lungs. Once these atria are filled, they contract, pushing the blood into their respective ventricles.
• Ventricular Action- Post atrial contraction, the ventricles become active. The right ventricle directs the deoxygenated blood it has received to the lungs, where it gets oxygenated. Concurrently, the left ventricle pumps out the oxygen-rich blood, ensuring its delivery to the various body parts, nourishing every cell with essential oxygen and nutrients.
• Valves in Action– Integral to this process are the heart’s valves. These valves ensure a one-way flow, preventing any backward movement of blood. This unidirectional blood flow is vital for efficient blood transportation.
• Significance- This structured sequential functioning is indispensable for proficient circulation. It ascertains that each body part timely receives oxygen-rich blood essential for cellular activities and simultaneously ensures deoxygenated blood is directed back for oxygenation.

Question 10- Explain the concept of a heartbeat, its relevance, and how it can be monitored and assessed.

Answer- A heartbeat stands as a testament to life, characterised by the rhythmic contraction and relaxation of the heart muscles.

• Definition and Importance- The heartbeat, a rhythmic phenomenon, occurs continually. This regular contraction and relaxation of the heart muscles ensure an uninterrupted flow of blood, which carries vital oxygen and nutrients, to the entirety of the body.
• Muscular Walls- The chambers of the heart possess muscular walls which play a vital role in producing a heartbeat. These muscles undergo rhythmic contractions and relaxations, thus powering the heart’s essential pumping action.
• Sensing the Heartbeat- One can feel this tangible rhythm by simply placing a hand over the left side of the chest. It acts as a palpable reminder of the continuous cycle of life in the biological domain.
• Stethoscope – A Diagnostic Tool- To get a more precise understanding of the heartbeat, doctors employ an instrument called the stethoscope. This tool amplifies the heart’s sounds, allowing a comprehensive auditory examination. It consists of various parts, including a sensitive diaphragm in the chest piece and two earpieces connected via a tube. All these components collaboratively present the heart’s sounds with utmost clarity. By listening to these sounds, doctors can derive crucial insights about the heart’s condition. Variations in rhythm, strength, or consistency can hint at potential heart-related issues, aiding in precise diagnostics and timely treatment.

Question 11-Discuss the role and structure of a stethoscope in diagnosing heart conditions.

Answer- The stethoscope is an invaluable diagnostic tool in the medical realm, especially when it comes to understanding and analysing the heart’s conditions.

• Structure- A stethoscope comprises several components. The chest piece, which typically includes a sensitive diaphragm, is placed against the patient’s chest. This diaphragm captures the heart’s sounds. Two earpieces, connected to the chest piece by a tube, convey these sounds to the doctor’s ears. This assemblage ensures that the heart’s sounds are relayed with clarity and precision.
• Diagnostic Relevance- By employing a stethoscope, doctors can listen more accurately to the heart’s beats. This auditory analysis provides an array of information. For instance, variations in the heartbeat’s rhythm might indicate arrhythmias. A difference in strength could be a sign of weakened heart muscles or other cardiac conditions. Furthermore, any inconsistency in the regular beating might hint at potential heart maladies.
• Conclusion- Thus, a stethoscope serves not just as a medium to hear the heart’s sounds but acts as a window to gauge the heart’s health, enabling accurate diagnostics and facilitating effective treatments.

Question 12- Explain how different animals have adapted various methods of waste excretion based on their environment and availability of water.

Answer- Different animals exhibit unique excretion mechanisms that have evolved according to their environmental contexts and water availability.

• Aquatic Animals- In a water-rich environment, aquatic animals like fish excrete cellular waste directly as ammonia. Ammonia, being highly soluble in water, easily dissipates in the aquatic surroundings, allowing fish to efficiently rid their bodies of this waste product.
• Land Animals (e.g., Birds, Lizards, Snakes)- In contrast, certain terrestrial animals like birds and reptiles excrete waste as uric acid, which is a semi-solid substance. This adaptation is crucial for water conservation, enabling these animals to survive in drier terrestrial habitats where water is not abundantly available.
• Humans- Humans primarily excrete waste in the form of urea, which is eliminated through urine. The kidneys play a vital role in this process, filtering waste from the blood and managing water and electrolyte balance.

Question 13- Discuss the steps involved in the excretion process, highlighting the journey from identification to expulsion.

Answer- The process of excretion encompasses several sequential steps that facilitate the effective removal of waste from an organism’s body-

• Identification and Capture- Initially, waste products generated from cellular metabolic activities are identified and captured. These wastes are then directed towards the respective excretory organs for further processing.
• Filtering and Processing- In this phase, waste materials undergo a filtration process. Essential substances and nutrients are retained, while harmful toxins and wastes are isolated for elimination.
• Expulsion from the Body- Post-filtration and processing, the refined waste products are directed towards exit points like the kidneys for final expulsion from the organism’s body, completing the excretion process.

Question 14- How are the respiratory and digestive systems interconnected with the excretory system in managing waste elimination?

Answer- The interconnectedness of the respiratory, digestive, and excretory systems illustrates a coordinated waste management strategy within an organism-

• Respiration and Excretion- The respiratory system collaborates with the excretory system in waste elimination. While the respiratory system primarily focuses on expelling carbon dioxide, the excretory system manages the removal of other cellular metabolic wastes.
• Digestion and Excretion– The digestive and excretory systems share a role in waste management. The digestive system is responsible for expelling undigested food, while the excretory system focuses on eliminating soluble metabolic wastes, ensuring a comprehensive waste removal process across different biological systems.

Question 15- What are the main components of the human excretory system and what roles do they play in the process of excretion?

Answer- The human excretory system consists of several key components, each playing a specific role in the removal of waste products from the body.

• Kidneys- The kidneys are bean-shaped organs located in the abdominal cavity and act as blood filtration powerhouses. Their primary function is to filter the blood, separating useful substances from the harmful ones, and producing urine as a result.
• Ureters- The ureters are elongated, tube-like structures connecting the kidneys to the urinary bladder. Their role is to transport the filtered urine from the kidneys to the urinary bladder for temporary storage.
• Urinary Bladder- The urinary bladder acts as a reservoir for the storage of urine. It securely holds the urine and releases it periodically as the body requires, a process known as urination.
• Urethra- The urethra is a muscular tube through which urine exits the body. It is the final part of the excretory pathway, facilitating the expulsion of urine outside the body.

Question 16- Explain the process of urine formation and its composition.

Answer- Urine formation is a three-step process involving filtration, transportation, and expulsion.

• Filtration- This occurs in the kidneys, where blood flows through countless capillaries. Essential substances and waste products present in the blood get filtered, with useful compounds being retained, and waste materials dissolved in water, forming urine.
• Transportation- Post-filtration, the urine moves via the ureters and gets stored temporarily in the urinary bladder.
• Expulsion- When the urinary bladder is full, the urine gets expelled from the body through the urethra during the process of urination.

In terms of composition, an adult typically excretes about 1 to 1.8 litres of urine daily. The urine is composed of around 95% water, 2.5% urea, and the remaining 2.5% consists of various waste residues.

Question 17- Discuss the concept of dialysis and when it is applied.

Answer- Dialysis is a medical procedure used when a person’s kidneys fail due to infections, injuries, or other medical conditions. It substitutes the natural function of the kidneys by filtering the blood and removing waste products from the body. Dialysis involves the use of an artificial kidney, or dialyzer, to purify the blood. During the procedure, blood from the patient’s body is diverted to the machine where it is cleaned and the waste products are removed, and then the cleaned blood is returned back to the body. Dialysis thereby helps in maintaining the body’s internal equilibrium in the absence of natural kidney function.

Question 18- Describe the process of photosynthesis in plants, including its location, the main ingredients, and the products formed.

Answer- Photosynthesis is a pivotal process in plants that ensures their sustenance and plays a significant role in the balance of life on Earth. This process predominantly occurs in the chloroplasts of green plant cells, with the majority taking place in the leaves. Two essential ingredients form the foundation of photosynthesis-

• Water- This is primarily absorbed by the roots of the plant from the surrounding soil. The water then gets transported to the leaves, where it becomes available for photosynthesis.
• Carbon Dioxide- Plants obtain carbon dioxide from the atmosphere. The stomata, tiny pores present on the surface of leaves, facilitate the intake of this carbon dioxide.

Upon the absorption of sunlight by the chlorophyll (the green pigment in leaves), photosynthesis commences. This sunlight energy is harnessed to convert water and carbon dioxide into glucose, a type of sugar. Glucose serves as the primary energy source for the plant, facilitating its growth, repair, and various metabolic activities. Additionally, as a byproduct of photosynthesis, oxygen is released into the atmosphere, which is vital for the respiration of most living organisms on Earth.

Question 19- Explain the importance of transportation in plants and the role of roots and root hairs in this process.

Answer- Transportation in plants is of paramount importance, serving a multitude of purposes vital for the survival, growth, and reproduction of the organism. Its significance can be categorised into the following-

• For Growth- Every cell within the plant body necessitates certain nutrients and energy. Transportation ensures that these cells acquire what they need, thereby promoting growth and the repair of damaged cells.
• For Reproduction- Reproductive processes, such as flowering and seed formation, rely heavily on the transport of essential nutrients to specific reproductive structures.
• For Response- Plants can detect and respond to various environmental stimuli, like light or gravity. This is made possible due to the transportation of hormones and other signalling molecules that modulate these responses.

The role of roots in this transport process is foundational. Roots, particularly the root hairs, are specialised structures that absorb water and mineral nutrients from the surrounding soil. Root hairs, being in close proximity to water sources situated between soil particles, enhance the absorption capability of plants. Their strategic design and position allow them to efficiently capture essential water and minerals dissolved in water, ensuring the plant remains hydrated and nourished.

Question 20- Discuss the roles and significance of the vascular tissues, xylem, and phloem in plants.

Answer- Vascular tissues in plants, specifically xylem and phloem, play a pivotal role in the transportation system of the organism. These tissues are specialised collections of cells that work in tandem to ensure the efficient transport of water, nutrients, and food throughout the plant.

• Xylem– Xylem tissues can be visualised as a series of pipes that form a continuous network across the plant, enabling the transport of water and nutrients. Their primary role is to connect the roots, where water and minerals are absorbed, to the leaves through stems and branches. This ensures that the water and nutrients vital for photosynthesis and other cellular processes are effectively delivered to all parts of the plant.
• Phloem– Once food, primarily glucose, is synthesised in the leaves via photosynthesis, the phloem tissue steps in to distribute this nutrition throughout the plant. Phloem’s primary function is to ensure that this synthesised food reaches every part of the plant, irrespective of whether those parts are directly involved in the food synthesis process or not.

Question 21- Explain the process and significance of transpiration in plants.

Answer- Transpiration is a vital physiological process in plants where they lose water in the form of water vapour, primarily from the surface of their leaves. This process begins with the absorption of water and mineral nutrients from the soil. While the plant utilises a significant portion of this absorbed water for various metabolic activities, a substantial amount remains surplus. This excess water is subsequently evaporated from the surface of leaves through minute openings known as stomata. Stomata serve as key regulators of this process, acting as gateways for the water vapour to exit the plant.

The significance of transpiration are as follows- 

• Suction Pull Generation- One of the primary benefits of transpiration is the creation of a suction force or vacuum. This force aids the plant in drawing water from the roots and transporting it upwards against the force of gravity. This ensures that every part of the plant receives an adequate water supply, essential for various physiological activities.
• Temperature Regulation- Just as humans sweat to regulate body temperature, plants use transpiration as a cooling mechanism. The evaporation of water during transpiration helps dissipate excess heat, preventing the plant from overheating. This is crucial as plants need to maintain an optimal temperature range for various metabolic activities.

Question 22- Describe the role of stomata in the process of transpiration and how it influences water transport in plants.

Answer- Stomata are small openings mainly found on leaf surfaces involved in the process of transpiration. They allow excess water to evaporate from the plant, assisting in the release of water vapour into the atmosphere. This evaporation process, primarily occurring through stomata, creates a suction force. This force helps in transporting water and essential nutrients from the roots upwards to different parts of the plants, overcoming gravitational pull, ensuring that all parts of the plant receive the necessary nutrients for growth and functioning.

Also Check – NCERT Solutions for Class 7 Science  Chapter 11-Transportation in Animals and Plants

Question 23- How does transpiration help plants adapt to their environment?

Answer- Transpiration aids plants in adapting to their environment in several essential ways. Primarily, it helps in regulating the plant’s temperature, preventing it from overheating, especially in warm conditions. This is crucial for the plant’s survival and proper functioning of metabolic activities. Transpiration also helps in maintaining the internal water balance of the plant by releasing excess water. This process ensures that plants have an adequate amount of water necessary for various cellular activities, allowing plants to maintain optimal internal conditions, which is crucial for their survival and growth in various environments.

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