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Cell Biology - Plant vs. Animal Cells

Grade 6IB

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

🔑Concepts

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The Cell Theory: All living organisms are made of cells, which are the basic unit of life. New cells are produced from existing cells.

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Plant Cells: Characterized by a rigid cell wall made of cellulose and chloroplasts used for photosynthesis to produce glucose (C6H12O6C_6H_{12}O_6).

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Animal Cells: Lack a cell wall and chloroplasts, allowing for irregular shapes. They contain small, temporary vacuoles rather than one large permanent vacuole.

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Shared Organelles: Both types contain a Nucleus (DNA storage), Cytoplasm, Cell Membrane (regulates H2OH_2O and O2O_2 flow), and Mitochondria for cellular respiration.

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Photosynthesis in Plants: The process takes place in chloroplasts where 6CO2+6H2O+extlightenergyightarrowC6H12O6+6O26CO_2 + 6H_2O + ext{light energy} ightarrow C_6H_{12}O_6 + 6O_2.

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Mitochondria: Known as the powerhouse of the cell, where oxygen and glucose react to release energy: C6H12O6+6O2ightarrow6CO2+6H2O+extATP(energy)C_6H_{12}O_6 + 6O_2 ightarrow 6CO_2 + 6H_2O + ext{ATP (energy)}.

📐Formulae

Total Magnification=Eyepiece Magnification×Objective Lens Magnification\text{Total Magnification} = \text{Eyepiece Magnification} \times \text{Objective Lens Magnification}

Actual Size of Specimen=Image SizeMagnification\text{Actual Size of Specimen} = \frac{\text{Image Size}}{\text{Magnification}}

💡Examples

Problem 1:

A student views a plant cell using a microscope with a 10×10\times eyepiece and a 40×40\times objective lens. What is the total magnification?

Solution:

10×40=400×10 \times 40 = 400\times

Explanation:

To find the total magnification, multiply the power of the eyepiece by the power of the objective lens being used.

Problem 2:

An unknown cell is observed under a microscope. It has a rectangular shape, a thick outer boundary, and green organelles. Identify the cell type.

Solution:

Plant Cell

Explanation:

The rectangular shape indicates a rigid cell wall, and the green organelles are chloroplasts containing chlorophyll for C6H12O6C_6H_{12}O_6 production, both of which are unique to plant cells.