18 classification/ taxonomy, 18.2

Question 1

what is the classification of organisms?

Answer 1

Taxonomy

Question 2

taxonomy

Answer 2

the discipline of naming and classifying organisms

Question 3

who invented binomial nomenclature?

Answer 3

Carolus Linnaeus

Question 4

binomial nomenclature

Answer 4

each species is assigned a two-part scientific name.

- the first part refers to the genus

Question 5

genus

Answer 5

a group of closely related species

Question 6

species consists of..

Answer 6

individuals who can interbreed

Question 7

Linnaeus’s system of classification has seven different levels. what are they?

Answer 7

• Kingdom
• Phylum
• Class
• Order
• Family
• Genus
• Species

Question 8

what are each of the 7 levels called?

Answer 8

taxon

Question 9

a genus is a group of…

Answer 9

a genus is a group of similar species

Question 10

a family is a group of…

Answer 10

a family is a group of similar genera

Question 11

what is a taxon composed of similar genera?

Answer 11

family

Question 12

what is a taxon composed of orders?

Answer 12

class

Question 13

compared to before, how do biologists now group organisms?

Answer 13

Early classifications were based on visible similarities. However, biologists now group organisms according to evolutionary relationships.

Question 14

phylogeny

Answer 14

the study of evolutionary relationships among organisms

Question 15

evolutionary classification

Answer 15

Method of grouping organisms together according to their evolutionary history

Question 16

key points of evolutionary classification

Answer 16

• Species within one genus are more closely related to each other than to species in another genus because all members of a genus share a recent common ancestor
• The higher level of the taxon, the farther back in time is the common ancestor of all the organisms in that taxon.

Question 17

cladistic analysis

Answer 17

-used to determine evolutionary relationships

Question 18

what is cladistic analysis based on?

Answer 18

derived characteristics

Question 19

derived characteristics

Answer 19

• Characteristics that appears in recent parts of a lineage, but not in its older members
• are new traits that arise as a group evolves over time
• Are found in closely related organisms but not in their distant ancestors
• Can be used to construct a cladogram

Question 20

cladogram

Answer 20

a diagram that shows the evolutionary relationships among a group of organisms

Question 21

do all organisms have DNA?

Answer 21

ALL organisms have DNA and RNA

Question 22

if the molecules are similar in different species, what does that tell you?

Answer 22

The more similar the molecules are in different species, the more recently the species shared a common ancestor, therefore, the more closely related they are

Question 23

molecular clock

Answer 23

a model that uses DNA comparisons to estimate the length of time that two species have been evolving independently

Question 24

DNA evidence

Answer 24

the more similar the DNA of two species are, the more recently they shared a common ancestor, and the more closely related they are in evolutionary terms