# UTPA STEM/CBI Courses/Surface Area to Volume Ratio

Course Title: General Biology 2
Lecture Topic: Surface Area to Volume Ratio
Instructor: Matthew Terry
Institution: UTPA

## Backwards Design

Course Objectives
* Primary Objectives- By the next class period students will be able to:
** Know what happens to surface area as volume increases
** Be able to give real world biological examples of the consequences of this
** Be aware of ways organisms get around this issue
** Predict habitat of aquatic insects based on morphology
* Sub Objectives- The objectives will require that students be able to:
** Calculate surface area and volume
** Think of examples from the biological world
* Difficulties- Students may have difficulty:
** Graphing
* Real-World Contexts- There are many ways that students can use this material in the real-world, such as:
** Determine if a structure functions as an organ for diffusion or temperature regulation based on morphology
** Be able to explain how specific behaviors compensate for these principles
Model of Knowledge
* Concept Map
** What is surface area?
** What is volume?
** How are volume and surface area connected?
** How does the shape of an animal affect these?
** Real world examples (Emperor penguins, lungs, gills, small intestine, whales, etc.)
** How are diffusion and heat conservation connected?
* Content Priorities
** Enduring Understanding
*** Surface Area to Volume ratio increase exponentially
*** This phenomenon affects the shape and behavior of organisms
** Important to Do and Know
*** Calculate and graph surface area and volume for cube as it increases in size
*** Use EXCEL to observe the relations of this change
*** Demonstrate diffusion using agar and dye
*** Demonstrate cooling of water in different volumes and shapes
** Worth Being Familiar with
*** How do insects compensate for this?
*** What organs are shaped to use this phenomenon?
*** Penguin example
Assessment of Learning
* Formative Assessment
** In Class (groups)
*** Compare measurements and graphs of different groups
*** Get examples of organs and/or organism behavior that demonstrate this principle
*** Place aquatic insects in their environment based on how they get their oxygen
** Homework (individual)
*** Complete and turn in a lab report
* Summative Assessment
** Weekly Quiz
** Final Exam

## Legacy Cycle

OBJECTIVE
By the next class period, students will be able to:
* Know what happens to surface area as volume increases
* Be able to give real world biological examples of the consequences of this
* Know ways that organisms get around this issue
* Predict habitat of aquatic insects based on morphology
The objectives will require that students be able to:
* Calculate volume and surface area
* Use excel
* Make logical predictions based on the learned concepts and observation
THE CHALLENGE
It's Not Easy Being Big: How does the relationship between surface area and volume impact living organisms?
GENERATE IDEAS
In class brainstorming and discussion
MULTIPLE PERSPECTIVES
* Emperor Penguin example
* Tissue pictures
RESEARCH & REVISE
Written and oral feedback from students
TEST YOUR METTLE
* Open oral questions to the class
* Written quiz at the beginning of the next lab
GO PUBLIC
Groups present their graphical results to the class

## Pre-Lesson Quiz

* How do you calculate the volume of a cube?
* How do you calculate the surface area of a cube?
* What happens to the surface area of a cube as you increase its size (volume)?
* Does this occur at the same rate as you increase volume?
* Would this process change if you used a different shape, such as a sphere?
* What cools faster, 100 ml of water or 1000 ml of water?
* How might you slow the rate at which the water cools?
* Name an organ for which diffusion is a major part of its function.
* Name one strategy that organisms use to slow the amount of heat they lose.
* Why does a kangaroo lick its arms?

## Test Your Mettle Quiz

* Which graph best represents the surface area to volume ratio of an elephant as it grows from a baby to an adult?
* What is the function of the alveoli in your lungs?
* How does asthma interfere with this function?
* Why are there no small marine mammals?
* Why are there small marine animals that are not mammals?
* What are three forms of insulation for arctic animals?
* How do emperor penguins survive the Antarctic winters?
* Gills in the diagram below are colored red. Which of the insects comes from an oxygen poor environment?
* Why are there no large insects?
* Describe the phenomenon of counter exchange and how it helps endotherms maintain their body temperature.