CH 26: Taxonomy and Systematics

Question 1

Taxonomy

Answer 1

Science of describing, naming, and classifying living and extinct organisms and
viruses

Question 2

Systematics

Answer 2

Study of biological diversity and the evolutionary relationships among
organisms, both extinct and modern

Question 3

What is at the top of the hierarchy of taxonomy and what groups comprise that level?

Answer 3

Domain is at the top and is comprised of Bacteria, Archaea, and Eukarya

Question 4

What are the taxanomic groups from highest to lowest?

Answer 4

Domain, Supergroup, Kingdom, Phylum, Class, Order, Family, Genus, Species

Question 5

What is a monophyletic group?

Answer 5

group of species, taxon, consisting of

the most recent common ancestor and all of its ancestors

Question 6

What is a paraphyletic group?

Answer 6

contains a common ancestor and some, but not

all, of its descendants

Question 7

What is a polyphyletic group?

Answer 7

contains a group of species with different common ancestors

Question 8

What are systematics usually based on?

Answer 8

morphological or genetic homology

Question 9

What is molecular systematics?

Answer 9

Using genetic homology to propose phylogenetic trees

-DNA and Amino Acid sequences are analyzed and closely related species have more similar sequences

Question 10

What is cladistics?

Answer 10

Study and classification of species based on evolutionary relationships
• Cladistic approach requires choosing the least complex tree
• Make phylogenetic trees or cladograms

Question 11

What are the character states in cladistics?

Answer 11

Symplesio-morphy
-Shared primitive character

Synapomorphy
-Shared derived character

Question 12

What kinds of mutations are most common and why?

Answer 12

Favorable mutations are rare.
Detrimental mutations are weeded out due to natural selection.
Neutral mutations are the most common.

Question 13

What are molecular clocks and how are they set?

Answer 13

Using accumulation of neutral mutations to measure evolutionary time

• Neutral mutations occur at a constant rate
• Divide the percentage of molecular difference by the number of years since they diverged from a common ancestor

Question 14

What is Horizontal Gene Transfer? What is Vertical Evolution?

Answer 14

• Any process in which an organism incorporates genetic material from another organism
without being the offspring of that organism
• Vertical evolution ~ Changes in groups due to descent from a common ancestor