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
- At node Z, as a third branch beside lizard and dog
- Inside the lizard branch, because pigeon came from lizard
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 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
- Tree 1, with 4 changes against 5 for Tree 2
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?
- Dog came from lizard, so the two are drawn together at node Z
- The tree is wrong, because animals that look most alike must be closest relatives
- 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?
- 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
- It is a drawing choice; only the nodes show how the groups are related
- Lamprey is the ancestor of the other four, which is why it is listed first
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
- Honeybee is the ancestor of pigeon, because it branches off first
- Wings show that honeybee and pigeon are close relatives, so the tree must be wrong
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 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
- Line 3: pine and flowering plant are sisters from node Y; neither came from the other
- Line 1: moss cannot be an outgroup because it lacks vascular tissue
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 1: branches at a node cannot be swapped unless the tree also gains a new trait
- Line 4: node Z cannot be shared by lizard and dog in both trees, because the swap moved that node
- Line 3: swapping does not change relationships; lizard is still the closest relative of dog
- Line 2: frog cannot be drawn beside dog in any cladogram that is drawn correctly
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 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
- Yes, because lizard and dog share node Z, which frog does not share
Zee says moss, drawn at the far left, is the ancestor of fern, pine and flowering plant. Which reply is best?
- Yes: tips on the left are older than tips on the right
- 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
- No: moss has no traits in the table, so it cannot be an ancestor