Lecture 2a

Question 1

Define: Taxonomy

Answer 1

The branch of biology that names and classifies both living and extinct species into heirarchieal order

Question 2

Define Taxon

Answer 2

a taxonomic group of any rank, such as species, family, or class

Question 3

define: species

Answer 3

a group of organisms that have the potential to interbreed in nature and produce viable, fertile offspring

Question 4

Define: Genus

Answer 4

a principle taxonomic group that ranks between family and genus, and is denoted by capitalized Latin name

Question 5

Define: Phylogeny

Answer 5

the evolutionary history of a group or organisms

Question 6

Define: systematics

Answer 6

Study of biological diversity and the evolutionary relationship among organisms

Question 7

Explain the following characteristics o f the Linnaean system of classification,
providing an example for each:
a. binomial nomenclature
b. hierarchical classification

Answer 7

Under Linnaean system, each organism is asigned 2 part scientific or latin name: 1st part is the organisms genus, 2nd part is the species epithet. This 2 part naming system is called binominal nomenclature example: caster canadensis. In addition linneaus also created a hierarchy for grouping organisms called hierarchical classification example: species, family, genus

Question 8

List the major taxonomic categories from most to least inclusive.

Answer 8

domain
kingdom
phylum
class
order
family
genus
species

Question 9

List 4 advantages of using scientific names instead of common names

Answer 9

1) scientific names are specific to a single species
2) species ofton have more than one common name, or different common names in different areas
3) common names change between languages
4) some common names do not properly reflect the kind of organism they represent

Question 10

Describe how linnaeus’ approach to classification differed from the approaches used by modern day biologist

Answer 10

Linnaeus grouped organisms based on physical similarities and functions
Darwin—-> all organisms are realated by desent from common ancestor

Biologist began classifying organisms based on the hypothesis regarding evolutionay realationships from systematics

Question 11

Explain why any phylogenetic diagram represents a hypothesis about evolutionary relationships among organisms.

Answer 11

Because evolutionary relationships between species are not know with certainty they are estimated from data

Question 12

Define sister taxa

Answer 12

groups that occupy adjacent branches on the treee; share an immediate common ancestor

Question 13

monophyletic

Answer 13

(of a group of organisms) descended from a common evolutionary ancestor or ancestral group, esp. one not shared with any other group.

Question 14

Paraphyletic

Answer 14

consists of an ancestral species and some, but not all, of its decendants

Question 15

Polyphyletic

Answer 15

Includes taxa, with different ancestors

Question 16

Describe 2 forms of evidence that scientists use to construct phylogenic trees

Answer 16

1) fossil records

2) similarities of living organisms

Question 17

Differentiate between analogy and homology and give an example of both

Answer 17

Analogy- similarities due to convergent evolution example is bird and bat wings

Homology- similarities due to shared ancestry
example: similarities in number and arrangement of bones in forelimbs of mammals

Question 18

Explain why it is important to distinguish between homology and analogy before selecting characters to use in the reconstruction of phylogenies.

Answer 18

Make sure it is actually about ancestry

Question 19

Differentiate between shared derived characteristics and shared ancestral characteristics

Answer 19

• Shared derived character: heritable trait that is found in two or more taxa, and that is present in the most recent common ancestor of the given taxa, but which is missing in more distant ancestors.
• These are characters that evolved in the lineage leading up to the group of organisms we’re studying, and which are unique to that group of organisms.
• Shared ancestral character: heritable trait that is shared with a distant ancestor (originated prior to the taxon in question).
• Example: Hair and lactation are shared derived characters that identify mammals; however, a vertebral column is shared ancestral character.

Question 20

define clade

Answer 20

a group of organisms believed to have evolved from a common ancestor, according to principles of cladistics

Question 21

differenciate between the 3 domains of life

Answer 21

Domain Bacteria,
• Diverse collection of species
• Live just about anywhere!!
• Amazing metabolic and structural diversity
• Very small – diameters of 0.5 – 5m
• Unicellular, but can form colonies
Domain Archea
• Less diverse than bacteria, but also discovered more recently.
• Tend to live in extreme environments (hot springs, salty lakes, deep ocean vents).
Domain Eukarya
Kingdoms still being debated…but for now:
• 8 Kingdoms: Animalia, Fungi, Plantae + 5 exclusively Protist.

Question 22

Describe Linnaeus’ original two -kingdom classification, and name two shortcomings of this scheme.

Answer 22

Plants: are organisms that cant move and make their own food

Animals: can move and can not make their own food

Problem: some animals can photosynthesize and some plants can absorb nutrients ( mushroom and bacteria)

Question 23

List 3 characteristics that these domains have in common

Answer 23

• DNA
• Ribosomes
• Plasma membrane
• Cytoplasm
• Genetic code (with some exceptions)
• mRNA encodes info used to produce proteins

Question 24

Name at least 3 features that differ between prokaryotes and eukaryotes?

Answer 24

Eukaryotes- nucleus, multicellular and unicellular and mitochondria

prokaryotes- no nucleus, unicellular and no mitochondria