Animal Reproduction and the Egg – Guided Learning

I designed this activity for my freshman biology class during the pandemic of 2020. My goal was to provide an overview of how vertebrate groups reproduce. Students in the past would focus on the amniote egg as part of unit on birds and reptiles. I would assign the amniote egg coloring as a way for students to learn the structures of the egg, like the amnion, chorion, allantois, and yolk.

The Eyewitness video series has a great episode on birds and the amniote egg which is now available on Youtube. I even have a worksheet to go with it, though Edpuzzle is also a great app for getting students to watch assigned videos.

This guided learning activity is an interactive exploration of reproduction in different animal groups. It starts with the difference between internal and external fertilization. I use engaging graphics, like gifs to focus student attention on important (or amazing) concepts. For example, swimming salmon show that dark red coloration may be the key to attracting a mate.

Next, students compare three types of reproductive strategies. Some animals, like snakes, lay eggs, whereas some animals retain eggs inside their bodies. Mammals, like humans, nourish the egg inside the uterus. I would like students to understand that in all of these strategies, there are similarities. Even though most mammals do not lay eggs, the retain some of the egg characteristics, like the amnion. ( Students can also do this activity: Amniote Egg Coloring.)

In later slides, students label an image of the amniote egg based on the descriptions. A fill-in slide contains the descriptions for what each membrane does. In another slide, students drag labels to an image.

In the final slide, students must synthesize what they have learned to create a Venn diagram comparing mammal reproduction to bird reproduction. A fun way to make the unit more interactive is to create “reptile” eggs by soaking bird eggs in vinegar. This will remove the calcium from the shell and make it soft and flexible.

In the past, I have also incubated chicken eggs. This can be a major project though, and you’ll need an incubator and fertilized eggs, plus a place to go with the chicks that hatch.