Question

part ii. use the cladogram to answer the questions.

1. what trait separates lampreys from tuna?
2. what separates a salamander from a turtle?
3. which organism is considered the oldest?
4. how do you know it is the oldest?

cladogram with lancelet (outgroup), lamprey, tuna, salamander, turtle, leopard; traits: vertebral column, jaws, four walking legs, amniotic egg, hair

Explanation:

Question 1

To determine the trait separating lampreys from tuna, we analyze the cladogram. Lampreys branch off before the "Jaws" trait appears, while tuna has jaws. So the trait is jaws.

Looking at the cladogram, salamander is before the "Amniotic egg" trait, and turtle has an amniotic egg. So the trait separating them is the amniotic egg.

In a cladogram, the organism with the fewest derived traits (closest to the outgroup) is the oldest. The lancelet is the outgroup, and lamprey is next, but among the listed, the lancelet is the outgroup, but if considering the main organisms, the lamprey? Wait, no, the lancelet is the outgroup (the oldest relative), but the first organism after outgroup is lamprey? Wait, no, the cladogram starts with lancelet (outgroup), then lamprey, then tuna, etc. So the oldest organism here (among the ones in the cladogram's main branches) is the lancelet? Wait, the question is "which organism is considered the oldest?" Looking at the cladogram, the lancelet is the outgroup, meaning it's the most distantly related and represents the ancestral form. So the oldest is the lancelet.

Answer:

Jaws

Question 2