Looking for authentic and easy-to-understand SEBA Class 10 Science Chapter 6 solutions for the new 2026–27 academic year? Access comprehensive textual exercise question answers, diagrams, and key explanations designed to help you score high marks in your HSLC board exams.
Blue question
Q1. Why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like humans?
Answer: In multicellular organisms like humans, all cells are not in direct contact with the surrounding environment. Diffusion is a slow process that cannot deliver oxygen to every cell quickly. Therefore, complex transport systems like blood circulation and lungs are required.
Q2. What criteria do we use to decide whether something is alive?
Answer: We decide if something is alive based on molecular movement and essential life processes such as nutrition, respiration, growth, movement, excretion, and reproduction.
Q3. What outside raw materials are used by an organism?
Answer: Organisms use outside raw materials like food, water, oxygen, and minerals. These materials provide energy and help in the growth, maintenance, and repair of body tissues.
Q4. What processes would you consider essential for maintaining life?
Answer: The essential life processes required for maintaining life are nutrition, respiration, transportation, and excretion.
Q5. What are the main differences between autotrophic nutrition and heterotrophic nutrition?
Answer: The main differences between autotrophic nutrition and heterotrophic nutrition are:
- In autotrophic nutrition, organisms prepare their own food from simple inorganic substances like carbon dioxide and water using sunlight, whereas in heterotrophic nutrition, organisms cannot prepare their own food and depend directly or indirectly on autotrophs for nutrition.
- Autotrophic nutrition requires chlorophyll and sunlight to synthesize food, whereas heterotrophic nutrition does not require chlorophyll or sunlight directly to obtain nutrients.
- Organisms showing autotrophic nutrition are called producers (e.g., green plants and certain bacteria), whereas organisms showing heterotrophic nutrition are called consumers or decomposers (e.g., animals, humans, and fungi).
Q6. Where do plants get each of the raw materials required for photosynthesis?
Answer: Plants get each of the raw materials required for photosynthesis from:
- Carbon dioxide is absorbed from the atmosphere through small pores called stomata present on the surface of the leaves.
- Water and minerals are absorbed from the soil through the root system and transported upward to the leaves.
- Sunlight is trapped directly from the Sun by chlorophyll present in the green chloroplasts of the plant leaves.
Q7. What is the role of hydrochloric acid in our stomach?
Answer: Hydrochloric acid (HCl) creates an acidic medium necessary for the action of the digestive enzyme pepsin. It also kills bacteria and other harmful microorganisms present in the food.
Q8. What is the main function of digestive enzymes?
Answer: Digestive enzymes act as biological catalysts that break down complex, insoluble food molecules into simpler, soluble forms so that they can be easily absorbed by the body.
Q9. How is the small intestine designed to absorb digested food efficiently?
Answer: The inner lining of the small intestine has millions of finger-like projections called villi, which increase the surface area for absorption. The villi are richly supplied with blood vessels that transport the absorbed nutrients throughout the body.
Q10. What advantage does a terrestrial organism have over an aquatic organism with regard to obtaining oxygen for respiration?
Answer: Air contains a much higher concentration of oxygen compared to the dissolved oxygen present in water. Therefore, terrestrial organisms spend less energy and have a slower, more efficient breathing rate than aquatic organisms.
Class 10 Science Chapter 6 Exercise Solutions SEBA
Q11. What are the different ways in which glucose is oxidised to provide energy in various organisms?
Answer: Glucose (a 3-carbon molecule called pyruvate after glycolysis) is broken down in three main ways:
- In the presence of oxygen (Aerobic respiration): Pyruvate breaks down in the mitochondria to produce carbon dioxide, water, and a large amount of energy.
- In the absence of oxygen (Anaerobic respiration in yeast): Pyruvate converts into ethanol, carbon dioxide, and energy.
- In the lack of oxygen (Anaerobic respiration in muscle cells): Pyruvate converts into lactic acid and energy, which causes muscle cramps.
Q12. How are oxygen and carbon dioxide transported in human beings?
Answer: Oxygen and carbon dioxide are transported in human beings by:
- Carbon dioxide is transported mainly in dissolved form in the blood plasma because it is more soluble in water than oxygen. It is carried from the body tissues through the circulatory system back to the lungs, where it diffuses into the alveoli and is exhaled
2. Oxygen is transported by binding to hemoglobin, a red pigment present in red blood cells. Oxygen diffuses from the lungs into the blood, binds with hemoglobin to form oxyhemoglobin, and is carried through the bloodstream to all body tissues.
Q13. How are the lungs designed in human beings to maximize the area for exchange of gases?
Answer: Within the lungs, the passage divides into smaller tubes ending in tiny, balloon-like structures called alveoli. Millions of alveoli provide a very large surface area. Their extremely thin walls and extensive network of blood capillaries ensure efficient diffusion and exchange of oxygen and carbon dioxide.
Q14. What are the components of the transport system in human beings? What are their functions?
Answer: The human circulatory system consists of three main components:
- Heart: Acts as a muscular pump to circulate blood throughout the body.
- Blood: The fluid tissue. Red blood cells carry oxygen, white blood cells fight infections, platelets help in clotting, and plasma transports nutrients, carbon dioxide, and wastes.
- Blood Vessels: Arteries carry oxygenated blood away from the heart, veins bring deoxygenated blood back to the heart, and capillaries facilitate exchange of materials with tissues.
HSLC Science Chapter 6 Question Answer
Q15. Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds?
Answer: Mammals and birds are warm-blooded animals that require high amounts of energy to constantly maintain a constant body temperature. Separation of oxygenated and deoxygenated blood by a four-chambered heart prevents mixing, ensuring a highly efficient supply of oxygen to body tissues.
Q16. What are the components of the transport system in highly organized plants?
Answer: Highly organized plants have two specialized vascular tissues for transport:
- Xylem: Transports water and dissolved mineral salts vertically upwards from the roots to the rest of the plant.
- Phloem: Transports photosynthetic food products (sucrose) from the leaves to all other growing and storage parts of the plant.
Q17. How are water and minerals transported in plants?
Answer: Water and minerals are absorbed from the soil by root hair cells via active transport. They move upward through the xylem vessels driven by two main forces:
- Root Pressure: Pushes water upwards in small plants or at night.
- Transpiration Pull: Evaporation of water through stomata creates a continuous suction pull that draws water to the highest parts of tall trees during the day.
Q18. How is food transported in plants?
Answer: The transport of soluble products of photosynthesis (food) in plants is called translocation, which takes place in the phloem tissue (sieve tubes and companion cells). Translocation is an active process that requires energy in the form of ATP to move food material up and down to wherever it is needed.
Q19. Describe the structure and functioning of nephrons.
Answer: • Structure: A nephron is the basic structural and functional filtration unit of the kidney. It consists of a cup-shaped Bowman’s capsule enclosing a cluster of blood capillaries called the glomerulus, followed by a long, coiled tubular structure.
• Functioning: Blood enters the glomerulus under pressure, where nitrogenous wastes, glucose, amino acids, and water are filtered into Bowman’s capsule. As the fluid flows along the tubule, useful substances are selectively reabsorbed into surrounding capillaries. The remaining liquid containing urea and excess salts forms urine.
SEBA Class 10 Science Chapter 6 Textual Solutions
Q20. What are the methods used by plants to get rid of excretory products?
Answer: Plants use several simple strategies for excretion:
- Gaseous Wastes: Excess oxygen and carbon dioxide are released through stomata in leaves.
- Transpiration: Excess water is released as water vapor through stomata.
- Stored Wastes: Waste products are stored in cellular vacuoles, old leaves that fall off, or dead xylem cells (bark).
- Secretions: Resins and gums are excreted into old xylem tissues. Some wastes are also excreted into the soil around the roots.
Q21. How is the amount of urine produced regulated in human beings?
Answer: The amount of urine produced is regulated based on the amount of excess water and dissolved wastes in the body. If the body contains extra water, a larger volume of dilute urine is excreted. If the body is dehydrated, the kidneys reabsorb more water back into the blood, producing a smaller volume of concentrated urine. This water reabsorption in the nephrons is also regulated by Antidiuretic Hormone (ADH).
Exercise
Q1. The kidneys in human beings are a part of the system for:
A) Nutrition
B) Respiration
C) Excretion
D) Transportation
Answer: C) Excretion Explanation: The kidneys filter nitrogenous waste products like urea and excess salts from the blood to form urine.
Q2. The xylem in plants is responsible for the:
A) Transport of water
B) Transport of food
C) Transport of amino acids
D) Transport of oxygen
Answer: A) Transport of water Explanation: Xylem tissue conducts water and dissolved mineral nutrients absorbed by the roots upwards to the rest of the plant.
Q3. The autotrophic mode of nutrition requires: A) Carbon dioxide and water B) Chlorophyll C) Sunlight D) All of the above
Answer: D) All of the above Explanation: Green plants use carbon dioxide, water, sunlight, and chlorophyll together to synthesize glucose during photosynthesis.
Q4. The breakdown of pyruvate to give carbon dioxide, water, and energy takes place in: A) Cytoplasm
B) Mitochondria
C) Chloroplast
D) Nucleus
Answer: B) Mitochondria Explanation: Aerobic respiration takes place in the mitochondria, where pyruvate is completely broken down in the presence of oxygen to release carbon dioxide, water, and energy in the form of ATP.
Class 10 Science Chapter 6 Question Answer SEBA 2026-27
Q5. How are fats digested in our bodies? Where does this process take place?
Answer: Fat digestion takes place in the small intestine. Bile juice secreted by the liver breaks down large fat globules into smaller emulsified droplets. Then, the enzyme lipase secreted by the pancreas digests these emulsified fats into fatty acids and glycerol.
Q6. What is the role of saliva in the digestion of food?
Answer: Saliva contains the enzyme salivary amylase, which breaks down complex starch molecules into simple sugars like maltose. Saliva also moistens the food and lubricates it, making it easy to swallow.
Q7. What are the necessary conditions for autotrophic nutrition, and what are its by-products?
Answer: • Necessary Conditions: Presence of chlorophyll, sunlight, carbon dioxide, and water.
• By-products: Oxygen gas is released as the main by-product along with water vapor.
Q8. What are the main differences between aerobic and anaerobic respiration? Name some organisms that use the anaerobic mode of respiration.
Answer: The main differences between aerobic and anaerobic respiration are:
- Aerobic respiration takes place in the presence of oxygen, whereas anaerobic respiration takes place in the absence of oxygen.
- Aerobic respiration results in the complete breakdown of glucose into carbon dioxide and water, whereas anaerobic respiration results in the incomplete breakdown of glucose into ethanol or lactic acid and carbon dioxide.
- Aerobic respiration releases a large amount of energy, whereas anaerobic respiration releases a very small amount of energy.
Organisms that use the anaerobic mode of respiration include yeast, certain bacteria, and human muscle cells during strenuous physical exercise.
Q9. How are the alveoli designed to maximize the exchange of gases?
Answer: The alveoli provide a large surface area for gas exchange. They have extremely thin, balloon-like elastic walls and are wrapped in an extensive network of blood capillaries, allowing oxygen and carbon dioxide to diffuse rapidly.
SEBA Class 10 Science Chapter 6 Solutions
Q10. What would be the consequences of a deficiency of hemoglobin in our bodies?
Answer: A deficiency of hemoglobin reduces the oxygen-carrying capacity of the blood, leading to a condition called anemia. This results in inadequate oxygen supply to body tissues, causing symptoms like fatigue, weakness, pale skin, shortness of breath, and dizziness.
Q11. Describe double circulation in human beings. Why is it necessary?
Answer: Double circulation means that blood flows through the heart twice during one complete cycle through the body. It consists of pulmonary circulation (heart to lungs and back) and systemic circulation (heart to body organs and back).
It is necessary because it completely separates oxygenated and deoxygenated blood, ensuring an efficient supply of oxygen to maintain a constant body temperature.
Q12. What are the main differences between the transport of materials in xylem and phloem?
Answer:The main differences between the transport of materials in xylem and phloem are:
- Xylem 1.transports water and dissolved mineral salts from the roots to the rest of the plant, whereas phloem transports food synthesized in the leaves to other growing and storage parts of the plant.
2. Transport in xylem is unidirectional, taking place only in an upward direction from roots to leaves, whereas transport in phloem is bidirectional, moving food both upward and downward depending on the plant’s requirements.
3. Transport of water and minerals through xylem occurs mainly due to physical forces like transpiration pull and root pressure without using cellular energy, whereas transport through phloem is an active process that requires metabolic energy in the form of ATP.
Q13. Compare the functioning of alveoli in the lungs and nephrons in the kidneys with respect to their structure and functioning.
Answer: • Structure: Alveoli are balloon-like, thin-walled air sacs surrounded by blood capillaries.
Nephrons are long, tubular units containing a capillary cluster called a glomerulus enclosed within a cup-shaped Bowman’s capsule.
• Functioning: Alveoli facilitate the exchange of gases (diffusing oxygen into the blood and removing carbon dioxide). Nephrons filter nitrogenous wastes, selective nutrients, and excess water from the blood to produce urine.
📌 Updated Solutions Notice: This post features complete, step-by-step SEBA Class 10 Science Chapter 6 Textual Questions and Answers revised for the 2026–27 session. All answers adhere strictly to the updated Assam Board (SEBA) Class 10 Science textbook curriculum.
💡 Ace Your Board Exams:
- Have questions about any specific step, diagram, or explanation in Chapter 6? Leave your questions in the comment section below!
- Bookmark this page for fast last-minute revision before your pre-boards and final tests.
- Share this study guide with your classmates to boost their preparation!