Taxonomy and systematics

Question 1

what is taxonomy?

Answer 1

Taxonomy is the science that identifies, names, and classifies living and extinct organisms and viruses.

Question 2

the first modern practitioner of taxonomy?

Answer 2

Carolus Linnaeus

Question 3

explain the binomial nomenclature

Answer 3

Linnaeus invented a system of binomial nomenclature in which each species is given a unique two-part name, called a binomial
The first part of the name identifies the
genus (plural, genera), and the second part is the specific epithet, or species name

Question 4

the taxonomic hierarchy

Answer 4

*Domain
* Kingdom
* Phylum
* Class
* Order
* Family
*Genus
* Species
* Subspecies

Question 5

what are systematics?

Answer 5

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

Question 6

Taxonomy groups are based on?

Answer 6

hypotheses regarding evolutionary relationships derived from systematics

Question 7

Phylogenetic tree

Answer 7

depicts the evolutionary history of a group of organisms and allows biologists to define evolutionary classifications

Question 8

Branch points in a phylogenetic tree are called?

Answer 8

nodes

Question 9

Clade

Answer 9

consists of a common ancestral species and all of its descendant species

Question 10

monophyletic lineages are called?

Answer 10

clades

Question 11

two lineages that share a node are called?

Answer 11

sister clades

Question 12

monophyletic taxa

Answer 12

includes one ancestral species and all its descendants

Question 13

polyphyletic taxa

Answer 13

includes species from separate lineages

Question 14

paraphyletic taxa

Answer 14

contains an ancestor and some but not all descendants

Question 15

Homologies

Answer 15

homologous characters resulting from common ancestry, so phenotypic similarities between organisms reflect underlying genetic similarities

Question 16

Homoplasies (analogies)

Answer 16

analogous characters do not result from common ancestry

Question 17

what is convergent evolution?

Answer 17

convergent evolution is the evolution of similar adaptations in distantly related organisms that occupy similar environments.

Question 18

what is homoplasy?

Answer 18

phenotypic similarity that evolved independently in different lineages

Question 19

what does traditional classification use?

Answer 19

it uses phenotypic similarities and differences

Question 20

the cladistic revolution

Answer 20

Cladistic analyses focus on recently evolved character states
Cladistics uses synapomorphies to reconstruct evolutionary history and classify organisms

Question 21

Each character can exist in two forms, described as character states, they are?

Answer 21

1. Ancestral characters (plesiomorphic)- Old forms of traits
2. Derived characters (apomorphic)- New forms of traits, relative to other organisms

Question 22

shared derived characters are?

Answer 22

synapomorphies ( Shared by two or more species or taxa and has originated in their most recent common ancestor)

Question 23

shared ancestral traits are?

Answer 23

symplesiomorphies (Shared by two or more different taxa and inherited from ancestors older than their last common ancestor)

Question 24

what are cladistics?

Answer 24

study and classification of species based on evolutionary relationships.

Question 25

phylogenetic trees are also called?

Answer 25

cladograms

Question 26

branch point

Answer 26

two species differ in shared derived characters

Question 27

Ingroup

Answer 27

group we are interested in (in the cladogram)

Question 28

Outgroup

Answer 28

species or group of species that is assumed to have diverged before the species in the ingroup

Question 30

steps in constructing a cladogram

Answer 30

1. choose species
2. choose characters
3. determine polarity of character states
4. analyze cladogram

Question 31

Molecular clocks

Answer 31

• Favourable mutations are rare, detrimental mutations are quickly eliminated so most mutations are neutral
• If neutral mutations occur at a constant rate they can be used to measure evolutionary time
• Not perfectly linear over long periods of time
  (Not all organisms evolve at the same rate, Differences in generation times between different species)

Question 32

what is horizontal gene transfer?

Answer 32

the transfer of genes between different species, any process in which an organism
incorporates genetic material from another
organism without being the offspring of that organism