Lecture 2: Classifying life and reconstructing phylogenies

Question 1

Taxonomical hierarchy:

Answer 1

Kingdom
Phylum
Class
Order
Family
Genus
Species 
(King Philip Came Over For Good Spaghetti)

Question 2

How do you write the genus and species name

Answer 2

UNDERLINE (+ italics)

Genus (capital) species (lower case )

Question 3

Phylogeny:

Answer 3

Development or evolution of a particular group of organisms

Question 4

What does PHYLOGENY have but TAXONOMY not have

Answer 4

TIME

Question 5

What happened in the 1970’s?

Answer 5

there was a revolution giving us phylogenetic or cladistic analysis

Question 6

Analogous:

Answer 6

Similarity due to convergent evolution (homoplasy) For example, the wings of a fly, a moth, and a bird are analogous because they developed independently as adaptations to a common function—flying.

Question 7

Homoplasy:

Answer 7

a character shared by a set of species but not present in their common ancestor

Question 8

Homologous:

Answer 8

Similarity due to common ancestry. examples of homologous structures are the bones in the forelimbs of various vertebrates, such as humans, dogs, birds and whales- from one LUCA, all used for different things

Question 9

symplesiomorphies:

Answer 9

shared ancestral characters

Question 10

synapomorphies:

Answer 10

shared derived characters

Question 11

Autapomorphies:

Answer 11

characters unique to a taxon

Question 12

Monophyletic group:

Answer 12

contains the latest common ancestor plus all, and only all, of its descendants (full branching from one common ancestor)

Question 13

Paraphyletic group:

Answer 13

diagnosed by plesiomorphies & not including all the descendants of a common ancestor. A paraphyletic group remains after one or more parts of a monophyletic group have been removed. (just a section on a monophyletic diagram)

Question 14

Polyphyletic group:

Answer 14

A group in which the most recent common ancestor is assigned to some either group itself. It is defined on the basis of convergence, or by non-homologous characters assumed to have been absent in the latest common ancestor. (2 separate branches from 2 bases with branches)

Question 15

The classification on life

Answer 15

started as 5, now 3.

• Domain Bacteria
• Domain Eukarya
• Domain Archaea

Question 16

Prok vs euk:

Organisms represent:

Answer 16

p = bacteria & cyanobacteria 
e = Protists, fungi, plants, animals

Question 17

Prok vs euk:

Cell size:

Answer 17

p = generally 1-10 micrometers 
e = generally 10-100 micrometers

Question 18

Prok vs euk:

Cellular organisation:

Answer 18

p = unicellular / colonial 
e = mainly multicellular with tissues and organs

Question 19

Prok vs euk: cell walls:

Answer 19

p = made of particular sugars and peptides 
e = made of cellulose or chitin (but lacking in animals)

Question 20

Prok vs euk:

Flagella & cilia:

Answer 20

p = some have flagella (but made of flagella protein) 
e = Flagella or cilia with micro tubules

Question 21

Prok vs euk:

Organelles:

Answer 21

p = no membrane-bound organelles 
e = membrane-bound chloroplasts and mitochondria

Question 22

Prok vs euk: metabolism & photosynthesis:

Answer 22

p = anaerobic, facultative aerobic 
e = aerobic

Question 23

Prok vs euk:

Genetic organisation:

Answer 23

p = loop of DNA in cytoplasm 
e = DNA in chromosomes in membrane-bound nucleus

Question 24

Prok vs euk:

Reproduction:

Answer 24

p = by binary fission. Dominantly asexual but some parasexual 
e = by mitosis or meiosis. Dominantly sexual

Question 25

It is thought that eukaryotic cells are made up of

Answer 25

Bacterial cells (act as their organelles)

Question 26

When was it discovered that there are two types of prokaryotes and what are they

Answer 26

1980’s

• Eubacteria (bacteria)
• Archaebacteria (Archaea)

Question 27

Archaebacteria vs Eubacteria

Answer 27

Archaebacteria are less numbers and diverse than Eubacteria & inhabit extreme environments

Question 28

Archaebacteria extreme environments e.g.=

Answer 28

• Thermophiles (v hot)

- Halophiles (v salty)