Chapter 23 - Evolutionary Patterns

Question 1

A grouping that includes an ancestor and some, but not all, of the descendants of that ancestor is described as:

Answer 1

paraphyletic.

Question 2

Phylogenetic trees represent hypotheses about the evolutionary relationships among groups of organisms.

Answer 2

True

Question 3

The tips of the branches on a phylogenetic tree represent:

Answer 3

present-day groups or extinct taxa

Question 4

The nodes on a phylogenetic tree represent:

Answer 4

common ancestors.

Question 5

The _____ level of the taxonomic hierarchy is more inclusive than a family, but less inclusive than a class.

Answer 5

order

Question 6

Imagine that you are chatting with one of your friends. He states that reptiles are obviously a monophyletic group, as this group contains all of the organisms (outside of fish) that possess scales. This statement is

Answer 6

false, as reptiles are a paraphyletic group; this group does not include birds, even though birds share a common ancestor with reptiles.

Question 7

Imagine that a taxonomist is provided with several flashcards that contain the names of different species. He would likely organize these flashcards to construct a phylogenetic tree. To do this, he would pay attention to which species belongs to which genus or class.

Answer 7

True

Question 8

Which of the following statements is true regarding a phylogenetic tree?

Answer 8

Phylogenetic trees could be considered physical representations of hypotheses—those that seek to establish the evolutionary relationships between different organisms.

Question 9

Consider a generalized tree of life, with three large branches representing Archaea, Bacteria, and Eukarya. These three branches would represent different:

Answer 9

domains