Read and build a cladogram
Grade 9 Science Worksheet - Challenge Me

Circle the best answer.
Read this first
Use this
Cladogram (model data), rooted, not to scale. Tips from left to right: lamprey, trout, frog, lizard, dog. Node W is the root, where lamprey and node X branch apart. Node X is where trout and node Y branch apart. Node Y is where frog and node Z branch apart. Node Z is where lizard and dog branch apart. The mark for jaws is on the branch to node X. The mark for four limbs is on the branch to node Y. The mark for keratin skin growths is on the branch to node Z. Table: Traits of six animals (model data), 6 rows. Columns: animal | jaws | four limbs | keratin skin growths | feathers. Row 1: lamprey | no | no | no | no. Row 2: trout | yes | no | no | no. Row 3: frog | yes | yes | no | no. Row 4: lizard | yes | yes | yes | no. Row 5: pigeon | yes | yes | yes | yes. Row 6: dog | yes | yes | yes | no. Pigeon is in the table but is not yet drawn on the tree.
Ari adds pigeon to the cladogram using only its new row in the table. Where does pigeon attach?
- At node Z, as a third branch beside lizard and dog
- Inside the lizard branch, because pigeon came from lizard
- As the sister of dog, because feathers and hair are both body coverings
- Below node Y, as the sister of frog, because both have four limbs
Traits of four model beetles (model data)
Cladogram (model data), rooted, not to scale. Tips from left to right: P, Q, R, S. Node W is the root, where node X and node Y branch apart. Node X is where P and Q branch apart. Node Y is where R and S branch apart.
beetle ridged shell long antennae striped legs P yes yes no Q yes yes yes R no no yes S no no no Tree 1, drawn here, pairs P with Q and R with S. Tree 2 pairs P with S and Q with R. Counting rule: a trait that both beetles of a pair share arises once, on the branch to that pair. A trait found in beetles of two different pairs arises twice, once on each pair's side. Every change counts as 1.
Bo compares two cladograms for the beetle table. Which tree needs fewer trait changes?
- Tree 1, with 4 changes against 5 for Tree 2
- Tree 2, with 5 changes, because more changes fit more of the table
- Both trees, because each one needs 4 changes
- Tree 1, with 3 changes, because striped legs count once
Traits of four plants (model data)
Cladogram (model data), rooted, not to scale. Tips from left to right: moss, fern, pine, flowering plant. Node W is the root, where moss and node X branch apart. Node X is where fern and node Y branch apart. Node Y is where pine and flowering plant branch apart. The mark for vascular tissue is on the branch to node X. The mark for seeds is on the branch to node Y.
plant vascular tissue seeds flowers moss no no no fern yes no no pine yes yes no flowering plant yes yes yes Esme asks if vascular tissue helps decide whether pine is closer to fern or to flowering plant. What is the best answer?
- No; fern, pine and flowering plant all have it, so it cannot separate them
- Yes; it arose separately on the pine tip, so pine stands apart
- No; moss has it too, so it is useless for building any cladogram
- Yes; fern and pine both have it, so they must be the closest pair of the three
Cladogram (model data), rooted, not to scale. Kira sees lamprey drawn first and dog drawn last, yet both groups live today. What does the order of tips mean?
- Flipping node W would move lamprey last and change how the animals are related
- Lamprey is the simplest animal and dog the most advanced, so order shows progress
- Lamprey is the ancestor of the other four, which is why it is listed first
- It is a drawing choice; only the nodes show how the groups are related
Traits of four organisms (model data)
Cladogram (model data), rooted, not to scale. Tips from left to right: honeybee, trout, pigeon, dog. Node W is the root, where honeybee and node X branch apart. Node X is where trout and node Y branch apart. Node Y is where pigeon and dog branch apart. The mark for backbone is on the branch to node X. The mark for four limbs is on the branch to node Y.
organism backbone four limbs wings honeybee no no yes trout yes no no pigeon yes yes yes dog yes yes no Luz sees wings marked yes for both honeybee and pigeon, yet the tree puts them far apart. What explains this?
- Wings arose separately in each group, so they are analogous and show no closeness
- Wings are a shared derived trait, so honeybee and pigeon should share node X
- Wings show that honeybee and pigeon are close relatives, so the tree must be wrong
- Honeybee is the ancestor of pigeon, because it branches off first
Use this
Cladogram (model data), rooted, not to scale. Tips from left to right: lamprey, trout, frog, lizard, dog. Node W is the root, where lamprey and node X branch apart. Node X is where trout and node Y branch apart. Node Y is where frog and node Z branch apart. Node Z is where lizard and dog branch apart. Notebook: Notes on the animal cladogram (classmate's notebook), 4 lines. Columns: line, entry. Line 1: Node Z is the shared ancestor of lizard and dog. Line 2: The mark for keratin skin growths belongs on the branch to node Z. Line 3: Frog is drawn right beside lizard, so frog is the closest relative of lizard. Line 4: Lamprey is the outgroup for the other four animals.
Milo reads a classmate's notebook about the animal cladogram. Which line has the mistake?
- Line 3: drawing order does not show closeness; lizard shares node Z with dog
- Line 1: lizard and dog cannot share an ancestor if frog sits between them
- Line 2: keratin skin growths belong on the lizard tip and the dog tip
- Line 4: lamprey cannot be the outgroup of the other four, because it is drawn first
Use this
Cladogram (model data), rooted, not to scale. Tips from left to right: moss, fern, pine, flowering plant. Node W is the root, where moss and node X branch apart. Node X is where fern and node Y branch apart. Node Y is where pine and flowering plant branch apart. The mark for vascular tissue is on the branch to node X. The mark for seeds is on the branch to node Y. Notebook: Notes on the plant cladogram (classmate's notebook), 4 lines. Columns: line, entry. Line 1: Moss is the outgroup, so it branches off before the other three plants. Line 2: Seeds arose once, on the branch to node Y. Line 3: Pine is the ancestor of the flowering plant, so flowering plants came from pines. Line 4: Fern, pine and flowering plant share node X.
Noah reads a classmate's notebook about the plant cladogram. Which line has the mistake?
- Line 4: fern cannot share node X with the flowering plant, because fern has no seeds of its own
- Line 2: seeds should be marked on the pine tip and the flowering plant tip
- Line 1: moss cannot be an outgroup because it lacks vascular tissue
- Line 3: pine and flowering plant are sisters from node Y; neither came from the other
Cladogram (model data), rooted, not to scale. Ren claims that lizard is a closer relative of dog than frog is. Which claim with its reason is best?
Cladogram (model data), rooted, not to scale. Tips from left to right: lamprey, trout, frog, lizard, dog. Node W is the root, where lamprey and node X branch apart. Node X is where trout and node Y branch apart. Node Y is where frog and node Z branch apart. Node Z is where lizard and dog branch apart. The mark for jaws is on the branch to node X. The mark for four limbs is on the branch to node Y. The mark for keratin skin growths is on the branch to node Z. Cladogram (model data), rooted, not to scale. Tips from left to right: lamprey, trout, frog, lizard, dog. Node W is the root, where lamprey and node X branch apart. Node X is where trout and node Y branch apart. Node Y is where frog and node Z branch apart. Node Z is where lizard and dog branch apart. The mark for jaws is on the branch to node X. The mark for four limbs is on the branch to node Y. The mark for keratin skin growths is on the branch to node Z. W X Y Z lamprey trout frog lizard dog jaws four limbs keratin skin growths - No, because frog and dog both have four limbs, so they must pair up
- Yes, because lizard and dog share node Z, which frog does not share
- Yes, because lizard is drawn just before dog, so it is the ancestor
- No, because the tree is read left to right, and frog comes first
Traits of four animals (model data)
Cladogram (model data), rooted, not to scale. Tips from left to right: lamprey, trout, frog, dog. Node W is the root, where lamprey and node X branch apart. Node X is where trout and node Y branch apart. Node Y is where frog and dog branch apart. The mark for backbone is on the stem below node W. The mark for jaws is on the branch to node X. The mark for four limbs is on the branch to node Y.
animal backbone jaws four limbs lamprey yes no no trout yes yes no frog yes yes yes dog yes yes yes Tala says a backbone shows that trout is closer to dog than to lamprey. Which reply with its reason is best?
- Yes, because trout is the ancestor of dog and passed its backbone on
- Yes, because trout and dog both have a backbone, so they are the closest pair
- No, because lamprey, trout and dog all have a backbone; jaws groups trout with dog
- No, because lamprey has no backbone, so lamprey cannot be compared with trout and dog
Cladogram (model data), rooted, not to scale. Zee says moss, drawn at the far left, is the ancestor of fern, pine and flowering plant. Which reply is best?
Cladogram (model data), rooted, not to scale. Tips from left to right: moss, fern, pine, flowering plant. Node W is the root, where moss and node X branch apart. Node X is where fern and node Y branch apart. Node Y is where pine and flowering plant branch apart. The mark for vascular tissue is on the branch to node X. The mark for seeds is on the branch to node Y. Cladogram (model data), rooted, not to scale. Tips from left to right: moss, fern, pine, flowering plant. Node W is the root, where moss and node X branch apart. Node X is where fern and node Y branch apart. Node Y is where pine and flowering plant branch apart. The mark for vascular tissue is on the branch to node X. The mark for seeds is on the branch to node Y. W X Y moss fern pine flowering plant vascular tissue seeds - Yes: moss branches off first, so the other three plants came from moss long ago
- Yes: tips on the left are older than tips on the right
- No: moss has no traits in the table, so it cannot be an ancestor
- No: moss is a present-day group on its own branch; the shared ancestor is node W