OpenSciEd Unit 8.6 · Lesson 14 · 14.A
Look for: In the early phases of development, there are…
From Teacher Edition
Facilitation guidance from the lesson plan — what to notice in student thinking and how to respond while teaching.
Building towards
14.A.1 Analyze and interpret sketches of different species at different stages of embryological development to identify similarities and differences (patterns) in physical structures not evident in the fully formed anatomy.
What to look / listen for
What to look and listen for
Listen for students to say something like the following:
- In the early phases of development, there are many similarities in the structures of each of the organisms.
- It is difficult to tell the organisms apart early in development, but by later in development their physical structures begin to look more different.
- All the organisms early in development have a tail-like structure, an eye, an earhole or ear, and nubs where arms, fins, or legs will eventually develop.
What to do
If students struggle making comparisons between the different structures found in the embryo sketches, encourage them to think of an external structure that they know all the animals have, such as eyes. Then encourage them to look for evidence of this structure in the different sketches and color code it. Then prompt them to look for other common structures and color code if it is found in all or some of the embryo sketches. You will have a second opportunity to assess students in the following step.
Analyze and interpret the data with a partner. Display slide J. Say, Now work with a partner to compare what you both identified for the similarities and differences in the physical structures of the different animals. Record these in your notebook in the table you set up. You may wish to reproject slide H with the data table for students.
Give partners 8 minutes to compare their findings and fill in their data tables.
Bring the class back together. Display slide K and ask, What did you and your partner discuss?
Suggested prompt
Sample student response
What were some similarities you discovered in the physical structures of the organisms at different stages of development?
Note
Some examples are included here, but these are not exhaustive. Accept all student responses, encouraging them to explain the similarities specifically for each stage of development.
- Early in development, all four looked very similar.
- They each have a spot that looks like an eye and an ear hole.
- They each have five little nubs, or bumps where arms and legs and the stomach grow.
They all have a tail.
The tail looks like it has ridges on it, like where the backbone will be?
Later in development, the fish and salamander look more similar to each other and the chicken and turtle look more similar to each other.
What were some differences you discovered in their physical structures at different stages of development?
Note
Some examples are included here, but these are not exhaustive. Accept all student responses, encouraging them to explain the differences specifically for each stage of development.
- Later in the development, all four animals look different from each other.
- By the time the animals are right before hatching, they all look very different from each other and more similar to adult animals.