Module 6 Lesson 6 - 4 (Lab)

Lab — Effect of Temperature on Sex

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Introduction

Can eating sweet or salty foods determine if a pregnant couple will have a boy or a girl?

Despite some persistent folk tales, parents can do nothing while pregnant that will influence the sex of their child. However, this is not the case with other species. In this exploration, you will determine if a change in temperature has an effect on the sex of hatchling chickens or geckos. By doing so, you will see how environment can affect the expression of genes already present in the developing embryos.

Environmental conditions can have an effect on the expression of genes. Your textbook refers to the coloration of Siamese cats as an example. In Siamese cats, cooler regions of their body turn dark while warm regions stay light although all cells have the same genes for colour.

With this Gizmo, you can explore the effect of temperature on the sex of hatchling chickens or geckos. Because the genetics of the eggs are already determined before you manipulate the environment, any change in the male to female ratio will be a result of that manipulation.

 

Problem

Manipulate the temperature in an incubator of chicken or gecko eggs and record the ratio of male to female hatchlings. This will determine if environment has an effect on sex for these species.

 

Materials

For this simulation, you require access to the Internet and a word-processing program to record your results

 

Procedure

Complete a gizmo on the effect of temperature on sex and all related activities. Open the Effect of Temperature on Sex Gizmo.

Open Exploration Guide. In this investigation, you will follow all instructions listed in the Exploration Guide.

As you read and follow the instructions, be sure you can answer for yourself the questions listed.

 

Observations

During this lab, you will construct two larger collections of data: one for the effect of temperature on chicken hatchlings and one for the effect of temperature on gecko hatchlings. Follow the instructions given in the guide to complete the following tables.

Sample Observation Table

Temperature	Males Trial 1	Males Trial 2	Males Trial 3	Females Trial 1	Females Trial 2	Females Trial 3
25°C
26°C
27°C
28°C
29°C

Assessment Questions

Complete the assessment questions in the simulation and check your answers.