This activity might not be viewable on your mobile device.Video segment. Assistance may be required. How are cladograms constructed? Watch this short animation to find out how.

As you learned in the animation, cladograms can be constructed in four easy steps.

  1. Observe the organisms.
  2. Construct a data table.
  3. Create a Venn diagram.
  4. Build the cladogram.

Let's practice!

Steps one and two (observe and create a data table) have been completed for you. Analyze the data in the table.

4 Limbs
Air Sac
Amniotic
Egg
Jaws
Mammary
Glands
Total
"Yes"
Dog
Yes
Yes
Yes
Yes
Yes
 Interactive button. Assistance may be required.

?

5
Lamprey
eel
No
No
No
No
No
 Interactive button. Assistance may be required.

?

0
Salamander
Yes
Yes
No
Yes
No
 Interactive button. Assistance may be required.

?

3
Shark
No
No
No
Yes
No
 Interactive button. Assistance may be required.

?

1
Tuna
No
Yes
No
Yes
No
 Interactive button. Assistance may be required.

?

2
Turtle
Yes
Yes
Yes
Yes
No
 Interactive button. Assistance may be required.

?

4

Count the number of characteristics each organisms has by adding up the yeses. Click on the blanks in the last column of the chart above to check your answers.

The organisms that are most closely related share the most characteristics.

In the chart above, which two organisms are most closely related?
Interactive popup. Assistance may be required.

Check Your Answer

The dog and the turtle are the two organisms most closely related. Close Pop Up

Interactive exercise. Assistance may be required. Complete the Venn diagram below by dragging the picture into the correct location.

Interactive exercise. Assistance may be required. Complete the cladogram by dragging the animals and the characteristics to the correct location.