Download and Practice CBSE Class 10 Science Chapter 6 Life Processes MCQs
FAQs on CBSE Science Chapter 6 Life Processes Class 10 MCQ with Answers
1. What types of questions are considered important from Chapter 6, Life Processes, for the CBSE Class 10 Board Exam 2025-26?
For the CBSE Class 10 board exams, important questions from Life Processes cover a range of formats. You should prepare for:
- 1-mark questions: MCQs, assertion-reasoning, and very short answer questions focusing on definitions (e.g., peristalsis) and specific roles (e.g., function of alveoli).
- 3-mark questions: These often require you to explain a process briefly (e.g., breakdown of glucose by various pathways) or differentiate between concepts (e.g., aerobic vs. anaerobic respiration).
- 5-mark questions: These are detailed, long-answer questions that often include a diagram, such as explaining the process of double circulation or the mechanism of urine formation.
- Diagram-based questions: Identifying parts of the human digestive system, heart, or nephron and stating their functions.
2. Which diagrams from the Life Processes chapter are frequently asked in board exams and carry high marks?
Several diagrams from this chapter are crucial for scoring well. The most important ones that are frequently asked for 3 or 5 marks are:
- Human Heart (cross-section): To show the path of blood flow in double circulation.
- Human Excretory System: To illustrate the main organs involved.
- Structure of a Nephron: Often asked with a question on the mechanism of urine formation.
- Human Digestive System: To label glands like the liver, pancreas, and parts of the alimentary canal.
- Human Respiratory System: To trace the pathway of air to the alveoli.
3. What are some expected 5-mark questions from the Life Processes chapter?
Based on previous board trends, some of the most important 5-mark questions from this chapter involve explaining complex physiological processes. Be prepared for:
- Describing the complete process of digestion of carbohydrates, proteins, and fats in the human alimentary canal.
- Explaining the mechanism of urine formation in humans, focusing on ultrafiltration, selective reabsorption, and secretion.
- Illustrating double circulation in the human heart with a well-labelled diagram, explaining why it is necessary.
- Detailing the events of photosynthesis: light-dependent and light-independent reactions (Calvin cycle).
4. How should one structure an answer on 'double circulation' to score maximum marks?
To score full marks on this important question, your answer must be structured and complete. Go beyond a simple definition and include:
- Definition: Start by defining double circulation as a process where blood flows through the heart twice for each complete circuit of the body.
- Two Pathways: Clearly explain both the pulmonary circulation (heart to lungs and back) and systemic circulation (heart to body tissues and back).
- Diagram: Draw a schematic, block, or cross-sectional diagram of the human heart, clearly labelling the four chambers, major blood vessels, and using arrows to show the direction of blood flow for both circuits.
- Significance: End by explaining why this separation is vital for mammals and birds—it ensures an efficient supply of oxygen to the body to meet high energy demands and maintain a constant body temperature.
5. What are some important difference-based questions that can be asked for 3 marks from this chapter?
Difference-based questions are common in board exams. For full marks, always answer in a tabular format. Important comparisons from Life Processes include:
- Arteries and Veins: Based on the type of blood they carry (with exceptions), wall thickness, presence of valves, and blood pressure.
- Aerobic and Anaerobic Respiration: Based on the requirement of oxygen, end products, amount of energy released, and location within the cell.
- Autotrophic and Heterotrophic Nutrition: Based on the source of energy, raw materials, and organisms that exhibit each type.
- Transport by Xylem and Phloem: Based on the substance transported, direction of flow, and nature of the tissue (living or dead cells).
6. Why is the separation of oxygenated and deoxygenated blood in the hearts of mammals and birds a significant evolutionary advantage?
This is a high-order thinking question. The separation of oxygenated and deoxygenated blood, made possible by a four-chambered heart, is crucial for two main reasons:
- High Energy Efficiency: It prevents the mixing of oxygen-rich blood with oxygen-poor blood. This ensures that the body's cells receive a highly efficient supply of oxygen, which is necessary for aerobic respiration to produce a large amount of ATP (energy).
- Thermoregulation: Mammals and birds are warm-blooded (endothermic), meaning they maintain a constant body temperature regardless of the external environment. This process requires a significant amount of energy. The efficient energy production supported by the four-chambered heart helps them meet these high metabolic demands.
7. What is a common conceptual trap related to photosynthesis that students must avoid in exams?
A very common trap in questions about photosynthesis, especially in MCQs, is confusing the products with the reactants. Many students mistakenly identify oxygen as a raw material required for photosynthesis. It is essential to remember that oxygen is a by-product released during the photolysis (splitting) of water. The actual raw materials required for photosynthesis are carbon dioxide, water, and sunlight (energy), trapped by chlorophyll.
8. How would the life of a plant be affected if its phloem tissue is damaged?
This is an important application-based question. If the phloem tissue in a plant is damaged, the process of translocation will stop. Phloem is responsible for transporting the soluble products of photosynthesis (mainly sucrose) from the leaves (source) to other parts of the plant like roots, fruits, and storage organs (sinks). Without this transport:
- The non-photosynthetic parts, like roots, would not receive the necessary food for respiration and growth, eventually leading to their death.
- Sugars would accumulate in the leaves, which can inhibit photosynthesis.
- Overall, the plant would be starved of energy, leading to stunted growth and its eventual death.
