📘 AUXINS – Plant Growth Hormones (Class 10)

Описание: 📘 AUXINS – Plant Growth Hormones (Class 10)

Auxins – Growth-regulating plant hormones responsible for cell elongation and directional growth

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🔑 Key Points

1️⃣ What are Auxins?

Auxins are plant growth hormones.

Produced mainly in shoot tips and root tips.

They control plant growth and development.

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2️⃣ Major Functions of Auxins

✅ Cell Elongation

Auxins promote cell stretching and lengthening.

Cause stem to grow upwards.

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✅ Phototropism (Growth towards light)

Auxins move to the shaded side of the stem.

Cells on shaded side grow faster → plant bends towards light.

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✅ Gravitropism (Geotropism)

Roots: Auxins inhibit growth on the lower side → root bends downward.

Shoots: Auxins promote growth on lower side → shoot grows upward.

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✅ Apical Dominance

Auxins from the apical (top) bud suppress growth of side buds.

Promotes vertical growth of plant.

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🎯 Exam Focus

Definition of auxins ⭐

Role in phototropism & gravitropism ⭐⭐

Meaning of apical dominance ⭐

Source of auxins (shoot tip) – 1 mark question

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📝 Conclusion

Auxins are essential plant hormones that regulate cell elongation, directional growth, and plant form, helping plants respond to light and gravity.

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