Classification and evolution

Question 1

Why do we classify things?

Answer 1

for our convenience
make study of living things more manageable
easier to identify organisms
help see relationships between species

Question 2

Classification

Answer 2

process of placing living things into groups

Question 3

The 8 taxonomic levels:

Answer 3

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 4

Domain - 
Kingdom - 
Phylum - 
Class - 
Order -
Family -
Genus -
Species -

Answer 4

Archaea, Eubacteria, Eukaryotae

Plantae, Animalia, Fungi, Protoctista (all eukaryotes), Prokaryotae

group with same body plan

same general traits

additional info like meat-eating (Carnivora)

closely related genera (genus)

closely related species

all essentially the same with some variations

Question 5

As you descend to the lower taxonomic groups….

Answer 5

becomes increasingly difficult to separate closely related species and place species accurately, more detailed description of species needed

Question 6

Binomial system

Answer 6

uses genus name and species name to avoid confusion when naming organisms (genus always in capital, and name underlined/italics)

Question 7

Used Latin for binomial system as using a common name doesn’t work because…. (4)

Answer 7

same organisms may have different common name in different parts of one country
different common names used in different countries
translation of language may give different names
same common name may be used for different species in other parts of the world

Question 8

Biological definition of species

Answer 8

group of organisms that can freely interbreed to produce fertile offspring

Question 9

Phylogenetic definition of a species

Answer 9

group of individual organisms that are very similar in appearance, anatomy, physiology, biochemistry, genetics

Question 10

Aristotle’s early classification

Answer 10

plant or animal

animal further into live and move in water, live and move on land, more through air

Question 11

Prokaryotae

Answer 11

no nucleus, loop of DNA, naked DNA
no membrane-bound organelles
smaller ribosomes
cells smaller than eukaryotes
free-living or parasitic

Question 12

Protoctista

Answer 12

eukaryotic
mostly single-celled
wide variety of forms, only thing in common is don't belong to any other kingdom
plant-like or animal-like features
mostly free-living
autotrophic or heterotrophic nutrition

Question 13

Fungi

Answer 13

eukaryotic
single cells or have mycelium that consists of hyphae
chitin walls
multinucleate cytoplasm
mostly free-living and saprophytic (cause decay of organic matter)

Question 14

Plantae

Answer 14

eukaryotic 
multicellular
cellulose cell wall
autotrophic
contain chlorophyll

Question 15

Animalia

Answer 15

eukaryotic
multicellular
heterotrophic
move

Question 16

Convergent evolution

Answer 16

organisms not closely related independently evolve similar traits as a result of being adapted to similar environments or ecological niches.
(unrelated species look very similar)

Question 17

If we assume that ______________________ then differences seen today are result of ___________.
Differences between molecules in different species reflect ______________.

Answer 17

the earliest living things had identical versions of certain biological molecules

evolution

evolutionary relationships.

Question 18

What protein used in respiration do all living things that respire have?
How do we compare it?
Draw conclusions on what?

Answer 18

cytochrome c
amino acids in protein identified, compare sequence
sequence same=species closely related
sequences different=not closely related
more differences=less closely related

Question 19

Another molecule used to classify species?

Answer 19

DNA
more similar sequence in part of DNA=more closely related species
many differences=evolved separately for long time

Question 20

Bacteria are different from Archaea and Eukaryotae because………

Answer 20

different cell membrane structure
flagella with different internal structure
different enzymes for synthesising RNA
no proteins bound to genetic material
different mechanisms for DNA replication and synthesising RNA

Question 21

features that Archaea share with Eukaryotes

Answer 21

similar enzymes for synthesising RNA
similar mechanisms for DNA replication, RNA synthesis
production of some proteins that bind to their DNA

Question 22

Phylogeny

use what?

Answer 22

study of evolutionary relationships between organisms

phylogenetic tree

Question 23

Artificial classification

Answer 23

based on few characteristics
doesn’t reflect evolutionary relationships
limited info
stable

Question 24

Natural classification

Answer 24

uses many characteristics
reflects evolutionary relationships
lots of useful info
may change with advancing knowledge

Question 25

Monophyletic

Answer 25

all evolved from same species

Question 26

Intraspecific variation

Answer 26

variation between members of the same species

Question 27

Interspecific variation

Answer 27

differences between species

Question 28

Continuous variation

Answer 28

2 extremes and full range of values in between

e.g. height, length of leaves, number of flagella

Question 29

Discontinuous variation

Answer 29

distinct categories and nothing in between

e.g. gender, flagella or not, blood group

Question 30

Student’s t-test

Answer 30

compare 2 means