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Plants and Ecosystems - Parts of a Plant and Photosynthesis

Grade 3IB

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

🔑Concepts

Plants are made of several parts with specific roles: Roots anchor the plant and absorb H2OH_2O and minerals; the Stem provides support and transports nutrients; Leaves are the primary site for food production.

Photosynthesis is the process by which green plants use sunlight to synthesize food from CO2CO_2 and H2OH_2O.

Chlorophyll is a green pigment found in the chloroplasts of leaves that captures energy from sunlight.

During photosynthesis, plants release O2O_2 (Oxygen) as a byproduct, which is essential for the survival of most living organisms.

Plants are known as 'Producers' in an ecosystem because they create their own energy rather than consuming other organisms.

📐Formulae

Carbon Dioxide+Water+SunlightGlucose+OxygenCarbon\ Dioxide + Water + Sunlight \rightarrow Glucose + Oxygen

6CO2+6H2O+lightC6H12O6+6O26CO_2 + 6H_2O + light \rightarrow C_6H_{12}O_6 + 6O_2

💡Examples

Problem 1:

Identify the gas that plants take in from the atmosphere and the gas they release during the process of making food.

Solution:

Plants take in CO2CO_2 and release O2O_2.

Explanation:

Through small pores in the leaves called stomata, plants absorb Carbon Dioxide (CO2CO_2) for photosynthesis and exhale Oxygen (O2O_2) as a waste product.

Problem 2:

Which part of the plant is responsible for absorbing H2OH_2O from the soil, and how does it reach the leaves?

Solution:

The Roots absorb H2OH_2O, and the Stem transports it to the leaves.

Explanation:

Roots use osmosis to pull H2OH_2O from the earth. The stem contains tube-like structures (xylem) that act like straws to carry the water up to the leaves for use in photosynthesis.

Parts of a Plant and Photosynthesis - Revision Notes & Key Formulas | IB Grade 3 Science