Cell Size and Function

11th GradeScience50 min

Learning Objective

I can explain how cell size and surface area to volume ratio affect cell function.

Lesson Flow

Watch Video

9 min

Cell size | Structure of a cell | Biology | Khan Academy

Khan Academy

Guided Notes

10 min

Key concepts students will learn:

  • The width of pseud amonous bacteria is around one micrometer, while human egg cells have a diameter on the order of 100 micrometers.

  • The smallest bacterial cells discovered have a size of about a few hundred nanometers, and the limiting factor for cell size is the ratio of volume to surface area.

  • As a cell grows, the volume increases faster than the surface area, making it difficult for the cell to take in nutrients and get rid of waste.

Practice

15 min

11 questions • Multiple choice & Short answer

Exit Ticket

5 min

Explain how the surface area to volume ratio limits cell size. Be sure to include how nutrient and waste exchange are affected.

Teacher Guide

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  • Answer keys for all questions
  • Differentiation strategies
  • Extension activities
  • Printable student handouts