Cell Size and Surface Area

Free to teach as-is — the teacher guide, student handout, and slides are included.

Free — we'll email you an access link. Google Docs format.

Objective

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

Part 1 of 4

Warm-up video

Khan Academy · 5:12Vetted channel

We don't generate video — this one is by Khan Academy on YouTube. The practice questions and exit ticket below were drafted by AI for this objective, and every question is editable in the teacher guide.

Part 2 of 4

Key concepts

3 concepts

  1. 1

    Cells need resources from the outside world, which must make their way through the outer membrane, and waste products need to be released across that membrane.

  2. 2

    As the volume of a cell increases, the ratio between surface area to volume decreases, making it harder to exchange resources, waste, and energy.

  3. 3

    Cells can increase their surface area to volume ratio through folds in their membranes, allowing for more efficient exchange.

Part 3 of 4

Practice

10 questions

1

Why is the surface area to volume ratio important for cell function?

2

As a cell increases in size, what happens to its surface area to volume ratio?

Part 4 of 4

Exit ticket

Quick comprehension check

Explain how a cell's surface area to volume ratio affects its ability to exchange resources and waste with its environment. Be sure to include what happens to the ratio as a cell grows larger.

Sample answer included in the free materials

Get the materials

Teacher guide, student handout, and slides — free, in Google Docs format

  • Teacher Guide

    Complete lesson plan with answer keys and alternate activities

  • Student Handout

    Printable worksheet

  • Slides

    Ready to present

We'll ask for your email to send your access link — nothing else.

Teaching a group at a different level?

Where are your students right now? We'll rebuild this lesson to match — including the teacher guide, student handout, and slides, saved to your Google Drive.

Adapt This Lesson