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Living Things - Conditions for plant growth

Grade 3IGCSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

Plants are living things that require specific conditions to grow and stay healthy: light, water (H2OH_2O), air (CO2CO_2), and warmth.

Light: Plants use sunlight as energy to make their own food through a process called photosynthesis.

Water (H2OH_2O): It is essential for transporting nutrients from the soil and keeping the plant's structure firm (turgid).

Air: Plants breathe in Carbon Dioxide (CO2CO_2) from the air to create energy and release Oxygen (O2O_2).

Warmth: Temperature affects how fast a plant grows; most plants prefer a range of 15C15^{\circ}C to 30C30^{\circ}C.

Nutrients: Plants absorb minerals like Nitrogen (NN), Phosphorus (PP), and Potassium (KK) from the soil to stay healthy.

📐Formulae

Carbon Dioxide+WaterLightGlucose+Oxygen\text{Carbon Dioxide} + \text{Water} \xrightarrow{\text{Light}} \text{Glucose} + \text{Oxygen}

6CO2+6H2OC6H12O6+6O26CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2

ΔH=HfinalHinitial\Delta H = H_{final} - H_{initial}

💡Examples

Problem 1:

A student measures a sunflower plant on Monday. Its height is 12 cm12\text{ cm}. On Friday, the height is 20 cm20\text{ cm}. Calculate the growth (ΔH\Delta H).

Solution:

ΔH=20 cm12 cm=8 cm\Delta H = 20\text{ cm} - 12\text{ cm} = 8\text{ cm}

Explanation:

The change in height represents the growth of the plant over the 4-day period.

Problem 2:

If a plant is kept in a dark cupboard but given plenty of H2OH_2O, why will it eventually turn yellow and die?

Solution:

The plant lacks light energy.

Explanation:

Without light, the plant cannot perform photosynthesis to create glucose (food). The yellowing (chlorosis) happens because it cannot produce chlorophyll without light.

Problem 3:

Identify the gas a plant takes in from the air to make food.

Solution:

Carbon Dioxide (CO2CO_2)

Explanation:

Plants absorb CO2CO_2 through tiny holes in their leaves called stomata to use in the photosynthesis process.

Conditions for plant growth - Revision Notes & Key Formulas | IGCSE Grade 3 Science