CBSE Class 10 Science: Life Processes — Nutrition & Respiration 2026

Nutrition in Plants

• Autotrophic nutrition: photosynthesis; 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
• Heterotrophic nutrition in plants: Insectivorous (Venus flytrap), parasitic (Cuscuta), saprophytic (mushrooms)
• Minerals from soil: N from nitrates, Mg for chlorophyll, Fe for enzymes

Nutrition in Animals and Humans

• Heterotrophic; holozoic nutrition: ingestion → digestion → absorption → assimilation → egestion
• Human digestive system: mouth (amylase) → stomach (pepsin, HCl) → small intestine (bile, trypsin, lipase)
• Absorption: villi in small intestine; glucose/amino acids to blood; fatty acids to lymph

Respiration

• Aerobic: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + 38 ATP (in mitochondria)
• Anaerobic in yeast: glucose → 2 ethanol + 2CO₂ + 2 ATP; in muscles: glucose → 2 lactic acid + 2 ATP
• Breathing vs. respiration: breathing = gas exchange (physical); respiration = cellular (biochemical)

Transportation in Plants

• Xylem: carries water and minerals upward; dead tissue; driven by transpiration pull
• Phloem: carries dissolved sugars (photosynthates) bidirectionally; living tissue; pressure flow hypothesis
• Transpiration: loss of water vapour from stomata; drives water ascent

Transportation in Humans

• Blood: plasma + RBCs (O₂) + WBCs (immunity) + platelets (clotting)
• Heart: 4-chambered; double circulation: pulmonary (heart-lungs) and systemic (heart-body)
• Blood pressure: systolic (~120 mmHg)/diastolic (~80 mmHg); measured by sphygmomanometer

Excretion

• Removal of metabolic waste: CO₂ (lungs), urea (kidneys), sweat (skin)
• Kidney: filters ~180 L blood/day; produces ~1.5 L urine; nephron is functional unit
• Dialysis: artificial kidney filters blood when kidneys fail

CBSE Exam Questions

• What is the role of HCl in the stomach?
• Differentiate aerobic and anaerobic respiration
• Describe the path taken by light during photosynthesis