In-text Questions — Nutrition Basics — Life Processes

1. 12 marksNCERT Cl-10 Science, In-text Qs after §5.1, Q1

   Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?

   Hint. Diffusion only works efficiently over very short distances — think about how far the average human cell sits from the body surface.

   Step 1 — Recall what diffusion can actually do. Diffusion moves substances effectively only across small distances, which is why it's sufficient for simple organisms whose every cell is close to the body surface.

   Step 2 — Apply this to a large multicellular body. In humans, most cells lie deep inside the body, far from any surface in contact with the environment, so oxygen would have to travel a long distance to reach them by diffusion alone.

   Step 3 — State why that's a problem. Diffusion over such large distances is far too slow to keep up with the body's oxygen demand, so specialised respiratory and circulatory systems are needed instead.

   ✦ Answer: Diffusion only works efficiently over short distances, but most cells in a large body like a human's are far from the body surface — diffusion alone would be too slow to supply them with oxygen, which is why dedicated respiratory and circulatory systems are needed.

   Where students slip. Saying humans 'need more oxygen' as the reason — the real issue is distance and speed, not the total amount of oxygen required; even a small oxygen need would go unmet if it had to travel that far by diffusion alone.

2. 21 markNCERT Cl-10 Science, In-text Qs after §5.1, Q2

   What criteria do we use to decide whether something is alive?

   Hint. Think about what's happening even inside organisms that don't visibly move at all.

   Step 1 — Consider the most general sign. Movement is the broadest indicator — but it doesn't have to be movement of the whole organism; even where nothing visibly moves, molecules within cells are in constant motion.

   Step 2 — Broaden this to life processes. More fully, we judge something to be alive by whether it carries out the essential life processes — nutrition, respiration, transportation and excretion — since these together are what maintain its body.

   ✦ Answer: Movement — at the very least, molecular movement inside cells, even without visible movement of the whole organism — together with carrying out essential life processes like nutrition, respiration and excretion.

   Where students slip. Requiring visible whole-body movement as the only criterion — a tree doesn't walk around, but molecular-level movement and ongoing life processes are still happening inside it, which is what actually counts.

3. 31 markNCERT Cl-10 Science, In-text Qs after §5.1, Q3

   What are outside raw materials used for by an organism?

   Hint. Think about the two broad things a body needs from outside itself just to keep existing.

   Step 1 — Name the first use. Outside raw materials provide energy, which the organism needs to carry out its various activities and to maintain a state of order in the body even when at rest.

   Step 2 — Name the second use. They also supply the materials needed for growth, development and repair, since building new tissue and maintaining existing tissue both require a steady input of raw material.

   ✦ Answer: Outside raw materials are used for energy and for the growth, development and repair of the body.

   Where students slip. Mentioning only energy — raw materials are also the literal building blocks for growth and tissue repair, not just fuel.

4. 41 markNCERT Cl-10 Science, In-text Qs after §5.1, Q4

   What processes would you consider essential for maintaining life?

   Hint. This chapter is organised around exactly four such processes.

   Step 1 — Recall what maintaining life actually requires. A living body needs to keep bringing in energy and materials and keep removing what it doesn't need, while moving all of this around internally.

   Step 2 — Name the four processes. Nutrition (getting food/energy), respiration (releasing energy from food), transportation (moving materials within the body) and excretion (removing waste) are the essential processes, since without any one of them the body's internal balance breaks down.

   ✦ Answer: Nutrition, respiration, transportation and excretion.

   Where students slip. Adding growth and response as 'essential processes' here — those matter for a full biological picture, but this chapter's own four processes (covered chapter by chapter) are nutrition, respiration, transportation and excretion.

Solutions written by the tuition.in editorial team and checked against the NCERT Class 10 Science textbook, Reprint 2026-27 (jesc105.pdf) — five in-text question sets (21 questions total) plus one end-of-chapter Exercise (13 questions, not 20 as some older manifests claim). Unchanged by rationalisation; the chapter describes the breathing passage and the nephron's tubule in generic functional terms rather than naming every intermediate structure.. Questions are referenced from the NCERT textbook for identification.