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?
- Below node Y, as the sister of frog, because both have four limbs
- As the sister of dog, because feathers and hair are both body coverings
- Inside the lizard branch, because pigeon came from lizard
- At node Z, as a third branch beside lizard and dog
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 3 changes, because striped legs count once
- Both trees, because each one needs 4 changes
- Tree 1, with 4 changes against 5 for Tree 2
- Tree 2, with 5 changes, because more changes fit more of the table
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; fern and pine both have it, so they must be the closest pair of the three
- 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
Traits of five animals (model data)
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.
animal jaws four limbs keratin skin growths lamprey no no no trout yes no no frog yes yes no lizard yes yes yes dog yes yes yes Jun notes that a lizard and a frog can look more alike than a lizard and a dog, yet the tree pairs lizard with dog. Why?
- The tree is wrong, because animals that look most alike must be closest relatives
- Dog came from lizard, so the two are drawn together at node Z
- Trees follow shared derived traits, and lizard and dog share keratin skin growths
- The tree is mislabeled, since frog sits beside lizard and must be the closer pair
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?
- 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
- Flipping node W would move lamprey last and change how the animals are related
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 1: lizard and dog cannot share an ancestor if frog sits between them
- Line 3: drawing order does not show closeness; lizard shares node Z with dog
- 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 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
- Line 2: seeds should be marked on the pine tip and the flowering plant tip
- Line 4: fern cannot share node X with the flowering plant, because fern has no seeds of its own
Tree A tips from left to right
Lamprey, trout, frog, lizard, dog. Tree B (model data), rooted, not to scale, is Tree A with the two branches at node Y swapped. Tips from left to right: lamprey, trout, lizard, dog, frog. 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 node Z and frog branch apart. Node Z is where lizard and dog branch apart. Notebook: Notes on Tree B (classmate's notebook), 4 lines. Columns: line, entry. Line 1: Tree B comes from Tree A by swapping the two branches at node Y. Line 2: In Tree B, frog is drawn right beside dog. Line 3: So Tree B shows frog as a closer relative of dog than lizard is. Line 4: Lizard and dog share node Z in both trees.
Pia reads a classmate's notebook about Tree B, drawn here after the swap. Which line has the mistake?
- Line 4: node Z cannot be shared by lizard and dog in both trees, because the swap moved that node
- Line 1: branches at a node cannot be swapped unless the tree also gains a new trait
- Line 2: frog cannot be drawn beside dog in any cladogram that is drawn correctly
- Line 3: swapping does not change relationships; lizard is still the closest relative of dog
Use this
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?
- 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 frog and dog both have four limbs, so they must pair up
- No, because the tree is read left to right, and frog comes first
Zee says moss, drawn at the far left, is the ancestor of fern, pine and flowering plant. Which reply is best?
- No: moss has no traits in the table, so it cannot be an ancestor
- Yes: moss branches off first, so the other three plants came from moss long ago
- No: moss is a present-day group on its own branch; the shared ancestor is node W
- Yes: tips on the left are older than tips on the right