A fast, one-glance recap of Class 10 Science Chapter 5 (Life Processes) — for the full explanations, see the Solutions.
Revision Notes: Life Processes
- Life processes: nutrition, respiration, transportation, excretion — basic processes needed to maintain the body
- Autotrophic nutrition: organism makes its own food (e.g. green plants) — needs CO₂, water, sunlight, chlorophyll; releases O₂ as by-product
- Heterotrophic nutrition: organism depends on others for food (e.g. humans, Amoeba)
- Human digestion path: mouth (salivary amylase) → stomach (HCl + pepsin) → small intestine (bile emulsifies fat; pancreatic + intestinal enzymes; villi absorb nutrients) → large intestine (water absorption)
- Aerobic respiration: needs O₂, occurs in mitochondria, glucose fully broken down → more energy
- Anaerobic respiration: no O₂ needed, occurs in cytoplasm, glucose partially broken down (ethanol+CO₂ in yeast, or lactic acid in muscle) → less energy
- Human respiratory path: nose → trachea → bronchi → bronchioles → alveoli (gas exchange: huge surface area, thin walls, rich blood supply)
- Double circulation: blood passes through the heart twice per cycle (pulmonary + systemic) — keeps oxygenated/deoxygenated blood separate, needed for high, constant energy demand
- Excretory system: kidneys (basic unit: nephron) filter blood → urine → ureters → bladder → urethra
- Xylem: water/minerals, one-way (upward), dead cells, passive (transpiration pull)
- Phloem: food, both directions (source to sink), living cells, active transport (uses ATP)
- Key comparison: alveoli (gas exchange) vs nephrons (blood filtration) — both maximise surface area via millions of thin-walled, richly-vascularised units
See also: Extra Questions (HOTS) | Formulas Handbook
