CHAPTER 19

Question 1

Systematic biology

Answer 1

Uses traits to infer evolutionary relationships among organisms

Question 2

Taxonomy

Answer 2

The branch of biology concerned with identifying, naming, and classifying organisms

Early taxonomists relied on physical characteristics to classify organisms

Today taxonomists classify organisms into natural groups based on their evolutionary history using DNA analysis

Question 3

Linnean taxonomy

Answer 3

Carolus Linnaeus developed binomial system to name species

Binomial nomenclature names organisms using a 2 part Latin name: Genus, Specific Epithet

Question 4

Seven categories of classification

Answer 4

Kingdom 
phylum 
class 
order 
family 
genus 
species

Question 5

The three domain system

Answer 5

Prokaryotic organisms are placed in the domain bacteria and in the domain Archaea

Eukaryotic organisms are placed in the domain Eukarya

Question 6

Domain bacteria

Answer 6

Prokaryotic unicellular organisms

Produce asexually

Cyanobacteria are large photosynthetic prokaryotes

Most bacteria are heterotrophic

Breaks down organic remains thereby keeping chemical cycling going

Some bacteria are parasitic and cause disease

Question 7

Domain Archaea

Answer 7

Prokaryotic unicellular organisms

Reproduce asexually

Live in extreme environments:
Methanogens (anaerobic swamps)
Halophiles (salt lakes)
Thermoacidophiles (hot acidic environments)

The cell wall is diverse but not the same as the bacterial cell wall.

Question 8

Domain Eukarya

Answer 8

Unicellular or multicellular organisms

always have a membrane-bound nucleus

Sexual reproduction is common

Protests, fungi, plants, and animals are eukaryotes

Question 9

Phylogeny

Answer 9

Classification reflects phylogeny

One goal of systematics is to create follow genetic trees showing the evolutionary history of a group of organisms

Question 10

Interpreting a Phylogeny

Answer 10

A phylogenetic tree indicates common ancestors in lines of descent or lineages

When a new character evolves a new evolutionary path diverges from the old and a new lineage is formed

Different lineages diverging from a common ancestor have ancestral traits

Question 11

Ancestral traits

Answer 11

Characteristics shared by the ancestor in the species in its lines of descent

Question 12

Derived trait

Answer 12

Present only in a specific line of descent

Question 13

Cladistics

Answer 13

A cladogram is a diagram showing relationships among species based on shared derived traits

A clade is an evolutionary branch that includes a common ancestor and all its descendent species