Question 1

Which of the following best describes a monophyletic group in a phylogenetic tree?

Accepted Answer

A group that includes all descendants of a common ancestor and no others.

Question 2

In constructing a phylogenetic tree, what is the significance of the outgroup?

Accepted Answer

It provides a point of reference for determining which traits are ancestral.

Question 3

Which of the following statements about DNA and phylogenetic trees is correct?

Accepted Answer

DNA can be used to quantitatively compare the nucleotide sequences between taxa to get a measure of similarity.

Question 4

A shared derived character that is unique to a particular clade is called a:

Accepted Answer

Synapomorphy

Question 5

Why can DNA evidence sometimes overturn physical similarities when constructing phylogenetic trees?

Accepted Answer

Because physical features can be lost or gained independently in different lineages, leading to convergent evolution.

Question 6

Which of the following is an example of a shared ancestral character?

Accepted Answer

The presence of a backbone in all vertebrates.

Question 7

If two species share a trait that is not found in their most recent common ancestor, this trait is an example of:

Accepted Answer

Convergent evolution (homoplasy)

Question 8

Which of the following best explains why snakes and legless lizards are still grouped with other lizards despite losing their limbs?

Accepted Answer

They share a common ancestor with lizards that had limbs, so limb loss is a derived trait within the clade.

Question 9

Which of the following is NOT a correct statement about cladistics?

Accepted Answer

A polyphyletic group includes all descendants of a common ancestor.

Question 10

A researcher is comparing the nucleotide sequences of two species to determine their evolutionary relationship. Which method is she using?

Accepted Answer

Molecular phylogenetics

Question 11

Which of the following is a limitation of using only physical features to construct phylogenetic trees?

Accepted Answer

Physical features can be lost or gained independently in different lineages, making it hard to group species solely by this way.

Question 12

In a phylogenetic tree, which node represents the most recent common ancestor of a group of species?

Accepted Answer

The root node

Question 13

Which of the following best describes a paraphyletic group?

Accepted Answer

A group that includes a common ancestor and some, but not all, of its descendants.

Question 14

Which of the following is an example of a synapomorphy for mammals?

Accepted Answer

The presence of mammary glands.

Question 15

A phylogenetic tree shows that humans and monkeys share a more recent common ancestor with each other than with lemurs. What does this imply?

Accepted Answer

Humans and monkeys are more closely related to each other than either is to lemurs.

Question 16

Which of the following is the correct order of steps when building a phylogenetic tree using cladistics?

Accepted Answer

Identify shared derived characters, group taxa by synapomorphies, root the tree using an outgroup.

Question 17

If a phylogenetic tree is constructed using only shared ancestral characters, what is a likely outcome?

Accepted Answer

The tree may not accurately reflect evolutionary relationships because it does not distinguish between derived and ancestral traits.

Question 18

Which of the following best explains why it is important to use both molecular and morphological data when constructing phylogenetic trees?

Accepted Answer

Combining both types of data can provide a more accurate picture of evolutionary relationships, as each can compensate for the limitations of the other.

Question 19

Which of the following is a real-world example of a shared derived character (synapomorphy) used to define a clade?

Accepted Answer

The presence of feathers in birds.

Question 20

A biologist is trying to determine whether a group of organisms forms a monophyletic group. Which of the following must be true for the group to be considered monophyletic?

Accepted Answer

All members must share a common ancestor, and all descendants of that ancestor must be included in the group.

Phylogeny and Systematics: Understanding Evolutionary Relationships

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