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?
- As the sister of dog, because feathers and hair are both body coverings
- Inside the lizard branch, because pigeon came from lizard
- Below node Y, as the sister of frog, because both have four limbs
- 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 4 changes against 5 for Tree 2
- Tree 2, with 5 changes, because more changes fit more of the table
- Tree 1, with 3 changes, because striped legs count once
- Both trees, because each one needs 4 changes
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?
- 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; fern, pine and flowering plant all have it, so it cannot separate them
- 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 mislabeled, since frog sits beside lizard and must be the closer pair
- Trees follow shared derived traits, and lizard and dog share keratin skin growths
- 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
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 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
- Wings arose separately in each group, so they are analogous and show no closeness
- 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 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
- 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
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 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 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 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
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 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
- Yes, because trout is the ancestor of dog and passed its backbone on
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?
- 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
- 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