Is it correct to say: Writing photosynthesis products as starch and water?

Immediate products are glucose (C₆H₁₂O₆) and oxygen. Starch is a storage polymer formed later.

Is it correct to say: Assuming plants respire only at night?

Plants respire 24/7. At night only respiration is visible (no photosynthesis).

Is it correct to say: Confusing xylem and phloem functions?

XYLEM: water & minerals from roots up (unidirectional). PHLOEM: sugars from source (leaf) to sink (fruit, root); bi-directional.

Is it correct to say: Mixing up left and right sides of the human heart?

LEFT side (aorta) pumps OXYGENATED blood to the body. RIGHT side (pulmonary artery) sends DEOXYGENATED blood to the lungs.

Is it correct to say: Confusing translocation with transpiration?

TRANSPIRATION = water loss (mostly through stomata). TRANSLOCATION = sugar transport in the phloem.

Is it correct to say: Writing 'nephron makes urea'?

Urea is made in the LIVER; nephrons FILTER it out of blood into urine.

Life Processes

Nutrition, respiration, transportation and excretion in plants and animals — NCERT Class 10 Biology Ch 6

📐 7 formulas✏️ 3 examples🎯 6 practice⚖️ 6 marks🏫 CBSE📚 Class 10✓ 2025–26 syllabus

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Board Exam Tips

→Diagrams of human digestive, respiratory, circulatory and excretory systems — practise labelling 6 parts each.
→Aerobic vs anaerobic respiration equation is a repeated 2-mark question.
→Explain photosynthesis with balanced equation AND site (chloroplast, palisade cells).
→Difference between transport in xylem and phloem — a 3-mark table question.
→Nephron structure and function — key HOTS topic; label glomerulus, tubule and collecting duct.

📐 Formulas(7)

Photosynthesis (Overall)★ Board fav

6 C O_{2} + 6 H_{2} O sunlight, chlorophyll C_{6} H_{12} O_{6} + 6 O_{2}

Aerobic Respiration★ Board fav

C_{6} H_{12} O_{6} + 6 O_{2} ⟶ 6 C O_{2} + 6 H_{2} O + 38 ATP

Anaerobic Respiration (Muscle)

C_{6} H_{12} O_{6} ⟶ 2 C_{3} H_{6} O_{3} + 2 ATP

Anaerobic Respiration (Yeast)★ Board fav

C_{6} H_{12} O_{6} ⟶ 2 C_{2} H_{5} O H + 2 C O_{2} + 2 ATP

Cardiac Output

Cardiac Output = Stroke Volume \times Heart Rate

Rate of Transpiration

Rate \propto leaf area, temperature, \frac{1}{humidity}

Urine Formation Three Stages

Filtration \to Reabsorption \to Secretion

✏️ Solved Examples

1Solved Exampleeasy2 steps

Give the balanced equation for photosynthesis and name the site of the reaction.

Recall the equation

6 C O_{2} + 6 H_{2} O sunlight, chlorophyll C_{6} H_{12} O_{6} + 6 O_{2}

2Solved Exampleboard4 steps

Trace the path of a molecule of oxygen from an alveolus to a muscle cell in the leg.

Alveolus wall (thin) allows O₂ to diffuse into the blood capillary surrounding it.

3Solved ExampleHOTS4 steps

Explain how the structure of a nephron is suited to its function of urine formation. (Support with three points and a brief functional description.)

Bowman's capsule surrounds a network of high-pressure capillaries (glomerulus) — creates a large surface + high pressure for FILTRATION of blood plasma.

⚠️ Traps & Common Mistakes

⚠️Common Mistakes6

1
Writing photosynthesis products as starch and water
✓Immediate products are glucose (C₆H₁₂O₆) and oxygen. Starch is a storage polymer formed later.
2
Assuming plants respire only at night
✓Plants respire 24/7. At night only respiration is visible (no photosynthesis).
3
Confusing xylem and phloem functions
✓XYLEM: water & minerals from roots up (unidirectional). PHLOEM: sugars from source (leaf) to sink (fruit, root); bi-directional.
4
Mixing up left and right sides of the human heart
✓LEFT side (aorta) pumps OXYGENATED blood to the body. RIGHT side (pulmonary artery) sends DEOXYGENATED blood to the lungs.
5
Confusing translocation with transpiration
✓TRANSPIRATION = water loss (mostly through stomata). TRANSLOCATION = sugar transport in the phloem.
6
Writing 'nephron makes urea'
✓Urea is made in the LIVER; nephrons FILTER it out of blood into urine.

🎯 Practice Yourself

🎯Practice Yourself6 questions

Q1
State two differences between autotrophic and heterotrophic nutrition.
Q2
Give the balanced equation of anaerobic respiration in yeast and its two uses.
Q3
Why is the rate of breathing much faster in aquatic organisms than terrestrial?
Q4
Name the three main components of blood and one function of each.
Q5
State two differences between arteries and veins.
Q6
Where does aerobic respiration occur in a cell, and what is its main product besides ATP?

📝 Notes

Life Processes

Living organisms carry out six essential processes to stay alive: nutrition, respiration, transportation, excretion, control and reproduction. This chapter covers the first four.

1. Nutrition

Autotrophs (green plants) prepare their own food via photosynthesis.
Heterotrophs depend on autotrophs — holozoic (humans), saprophytic (fungi), parasitic (Cuscuta, tapeworm).
Human digestive tract: mouth → oesophagus → stomach → small intestine (main absorption) → large intestine → rectum → anus. Associated glands: salivary, liver, pancreas.

2. Respiration

Aerobic — glucose + O₂ → CO₂ + H₂O + 38 ATP (mitochondria).
Anaerobic (muscle) — glucose → lactic acid + 2 ATP (cramps during heavy exercise).
Anaerobic (yeast) — glucose → ethanol + CO₂ + 2 ATP (brewing, baking).
Path of air: nostrils → pharynx → larynx → trachea → bronchi → bronchioles → alveoli (gas exchange).

3. Transportation

In humans (blood + heart):

4-chambered heart; double circulation (systemic + pulmonary).
Arteries thick-walled; veins have valves; capillaries one-cell-thick for exchange.

In plants:

Xylem: water + minerals, root → leaf (transpiration pull).
Phloem: sucrose, leaf → other parts (translocation, active).

4. Excretion

Human urinary system: kidneys (nephrons) → ureters → bladder → urethra.
Each kidney has ~1 million nephrons; filtration in glomerulus, reabsorption in tubules, secretion regulated by hormones (ADH, aldosterone).
In plants: excess water lost as transpiration; gaseous wastes via stomata; solid wastes stored in old xylem/bark.