Phylogenetic Tree Worksheet showing a cladogram and questions about organism traits and relationships.

Here is the step-by-step solution to your Phylogenetic Tree Worksheet.

Step 1: Fill in the Trait Table (Question 1 & 7)

First, we need to look at the physical characteristics of each animal to see which ones have specific traits. This helps us group them later.

* Worm: Has cells (all animals do). Does not have legs, wings, hair, or eyes (in the context of this simple chart).
* Spider: Has cells and legs. It has 8 legs, so it does *not* have exactly "6 legs." It does not have wings, hair, or eyes (again, simplified for this chart level, though spiders do have eyes, usually "eyes" in these charts refers to complex vertebrate eyes or is a distractor, but let's stick to the obvious structural differences: legs vs no legs). *Correction:* Actually, looking at standard biology worksheets, spiders are arachnids. They have legs. They don't have 6 legs (insects do). They don't have wings.
* Carpenter Ant: Has cells, legs, and exactly 6 legs (it's an insect). It does not have wings (worker ants typically don't, or the chart simplifies this), hair, or eyes.
* Fly: Has cells, legs, 6 legs, and wings (it's an insect that flies).

Table for Question 1:
| Organism | cells | legs | 6 legs | wings |
| :--- | :---: | :---: | :---: | :---: |
| Worm | X | | | |
| Spider | X | X | | |
| Carpenter Ant | X | X | X | |
| Fly | X | X | X | X |

*(Note: For Question 7, the table asks for hair, legs, no tail, eyes. Since none of these invertebrates have hair or backbones/tails in the traditional sense, and "eyes" can be tricky, the main differentiator here is usually just legs. However, based on the first part of the worksheet, the key traits are Cells -> Legs -> 6 Legs -> Wings.)*

Step 2: Build the Cladogram (Question 2)

A cladogram shows evolutionary relationships. We start with the simplest organism and add branches as new traits appear.

1. Start: All of them have cells. So, they all go on the tree.
2. First Split: The Worm is the only one without legs. It branches off first at the bottom.
3. Next Trait: The remaining three (Spider, Ant, Fly) all have legs.
4. Second Split: The Spider has legs, but it does *not* have 6 legs (it has 8). So, the Spider branches off next.
5. Next Trait: The remaining two (Ant, Fly) both have 6 legs.
6. Third Split: The Carpenter Ant has 6 legs but no wings. It branches off next.
7. Final Trait: The Fly has 6 legs AND wings. It goes at the very top.

Order from bottom to top: Worm $\rightarrow$ Spider $\rightarrow$ Carpenter Ant $\rightarrow$ Fly.

Step 3: Explain the Placement (Question 3)

* Worm: I put the worm first because it is the only organism that does not have legs.
* Spider: I put the spider next because it has legs, but it does not have 6 legs like the insects do.
* Carpenter Ant: I put the ant after the spider because it has 6 legs, but it does not have wings.
* Fly: I put the fly last because it has 6 legs and it also has wings.

Step 4: Differentiating Traits (Question 4)

The traits that make the organisms different from each other as you move up the tree are:
1. Legs (Separates Worm from the rest)
2. 6 Legs (Separates Spider from Ant/Fly)
3. Wings (Separates Ant from Fly)

Step 5 & 6: Relationships (Questions 5 & 6)

* Question 5: Worms and spiders are more closely related than worms and ants? No.
* *How do you know?* On the cladogram, the Worm branches off at the very beginning. The Spider, Ant, and Fly are all grouped together closer to each other than any of them are to the Worm. Actually, the question asks "which two species are more closely related: worms and spiders or spiders and ants?"
* Let's re-read carefully: "According to your cladogram, which two species are more closely related: worms and spiders or spiders and ants?"
* Answer: Spiders and Ants are more closely related.
* Why? Spiders and Ants share a more recent common ancestor (the node where "legs" evolved) than Worms and Spiders do. Worms branched off before legs even existed.

* Question 6: Which species are flies most closely related to?
* Answer: Carpenter Ants.
* How do you know? They share the most recent branch point. They both have 6 legs. The Fly just added one more trait (wings) on top of what the Ant has.

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Final Answer:

1. Trait Table:
* Worm: cells [X]
* Spider: cells [X], legs [X]
* Carpenter Ant: cells [X], legs [X], 6 legs [X]
* Fly: cells [X], legs [X], 6 legs [X], wings [X]

2. Cladogram Order (from bottom/left to top/right):
1. Worm
2. Spider
3. Carpenter Ant
4. Fly

3. Explanation Sentences:
* The Worm is at the bottom because it does not have legs.
* The Spider is next because it has legs, but not 6 legs.
* The Carpenter Ant is next because it has 6 legs, but no wings.
* The Fly is at the top because it has 6 legs and wings.

4. Added Traits:
The traits added to the cladogram lines are: Legs, 6 Legs, and Wings.

5. Closest Relationship:
Spiders and Ants are more closely related. You know this because they share a more recent common ancestor on the tree (they both have legs) compared to the worm, which branched off earlier.

6. Fly's Relative:
Flies are most closely related to Carpenter Ants. You know this because they are right next to each other on the top branches and share the trait of having 6 legs.