Unit 2 Flashcards
(150 cards)
1
Q
history of organizing life
A
Carlus Linnaeus (sweden) established modern taxonomy (bionomial nomenclature)
2
Q
taxonomy
A
naming and classifying organisms
3
Q
phylogeny
A
the evolutionary relationships among organisms or their genes
4
Q
What are the 5 hypotheses portrayed in the phylogenetic tree?
A
1- morphology 2- paleontology 3- behavior 4- development 5- molecular
5
Q
morphology
A
anatomy, external structures, more in common (closer evolutionary relationship)
6
Q
limitations of morphology
A
difficult to compare distantly related species and some variation caused by environment
ex- leopard frogs N and Central America
7
Q
paleontology
A
includes when are where organisms lived (ancestral vs derived traits)
8
Q
limitations of paleontology
A
fossil record- few and fragmented
9
Q
behavior
A
active morphology
cultural vs inherited traits (bird and frog calls)
10
Q
developmental patterns
A
sea squirts and vertebrae both have notochord
11
Q
molecular data
A
DNA often used to construct phylogenetic trees
- mutations accumulate over time
- fewer differences= more closely related
12
Q
what are photogenically analyses important for?
A
studying the transmission of viruses
13
Q
how to (not) read a phylogenetic tree
A
time is read from root to tip
nodes are speciation events
relatedness = most recent common ancestor
14
Q
Basic principle of molecular clock
A
Average rate at which a given gene or protein accumulates changes- used to gauge time of particular split in phylogeny
15
Q
What does the molecular clock help with?
A
Dating evolutionary events
-rates constant so they can be used to predict divergence times
16
Q
What is an example of what a molecular clock can help with?
A
Timing of when HIV first entered human pop from chimp
17
Q
What is 16s rRNA? What does it code for?
A
- Small ribosomal subunit
- useful for comparing bacteria (common among all)
18
Q
Biological species concept
A
Species are groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups
19
Q
Limitations of biological species concept
A
Not asexual/ limited to certain point
20
Q
Morphological species concept
A
Appearance
21
Q
Limitations of morphological species concept
A
Young, look alike, cryptic species
22
Q
Group of organisms that can mate with one another and produce fertile offspring
A
Species
23
Q
Divergence of biological lineages and the emergence of reproductive isolation
A
Speciation
24
Q
Clade
A
Include all species linked by descent from a common ancestor
25
Monophyletic
Clade
26
Polyphyletic
Missing common ancestor
27
Paraphyletic
Missing some descendants
28
Taxon
Any species or group that we designate or name
29
How are new species formed?
Reproductive isolation between species
30
Reproductive isolation
No longer exchange genes
31
Reproductive isolation only affects
Sexually reproducing organisms
32
Allopatric
Populations separated by physical barrier
33
Examples of allopatric speciation
Continents drift, sea level changes, glaciers, climate changes
(Ozarks vs eastern highlands- fish)
34
Sympatric speciation
No physical isolation
35
Pre zygotic isolating mechanisms
Before fertilization occurs
36
3 examples of prezygotic isolating mechanisms
- mechanical
- behavior
- temporal
37
Mechanical isolation
Differences in size and shape of reproductive organs makes mating impossible
38
Behavior isolation
Individuals reject to fail to recognize potential mating partners
39
Temporal isolation
Mating periods do not overlap
40
Post zygotic isolating mechanisms
Reduce fitness of hybrid offspring
41
Examples of post zygotic isolating mechanisms
- low hybrid fitness
| - zygotes or adult offspring have lower fitness or hybrids are infertile
42
Similarities between eukaryotic and bacterial cells
- have cytoplasm
- have plasma membranes
- need to divide to produce more cells
- carry DNA on chromosomes
- copy DNA
43
Three differences antibiotics exploit
- ribosomes
- prokaryotes have circular DNA
- cell wall
44
Explain ribosomal difference
- prokaryotes have smaller ribosomes than eukaryotes (70s)
- both have rRNA and proteins =subunits of ribosome
- antibiotics bind to pockets in subunits of ribosomes
45
Describe difference of prokaryotes shape of DNA
- need DNA gyrase
- --uncoils DNA during replication and prevents "knots"
- --halts DNA replication, kills cell
46
Describe the difference of the cell wall
Made of peptidoglycan in bacteria
| --use to break bacteria into two groups (gram + and -)
47
How do bacteria form communities?
Aggregate into bio films
48
How do bacteria reproduce?
Asexually - binary fission
49
Bacteria 2 locations of DNA
- bacterial chromosome (circular DNA)
| - plasmids (DNA connected to chromosome)
50
Survival strategies of bacteria
- bacteria aggregate into bio films, surrounded by protective slime
- endospores
51
Endospores
- Produced by bacillus when nutrients are depleted
- resistant to desiccation, heat, and chemicals
- resistant to harsh conditions (anthrax)
52
Shapes of bacteria
Spirilla (spirals)
Bacilli (rods)
Cocci (sphere)
53
Size of bacteria
Human hair (100 um)- eukaryotes (60 um) - prokaryotes (1 um) - viruses (0.1 um)
54
Arrangement of bacterial cells- pairs
Diplococci and diplobacilli
55
Arrangement of bacterial cells- clusters
Staphylococci
56
Arrangement of bacterial cells- chains
Streptococci, streptobacilli
57
Principle of gram stain
Separate bacteria into 2 groups via differential stain
58
Explain gram stain
Gram +: peptidoglycan = thick and outside (purple)
Gram -: peptidoglycan = think and covered by another layer (pink)
59
How do we currently define a "species" of bacteria?
- no widely accepted concept
- sequence common 16s rRNA and define cut offs of 95-97%
- operational taxonomic units (otu)
60
What are the four phyla common the gut?
- actinobacteria
- bacterioidetes
- proteobacteria
- firmicutes
61
Actinobacteria
- high GC content
- most antibiotics
- ex: streptomyces
62
Bacterioidetes
-gram negative
-rod: bacilli
-non spore forming
Ex) bacteriodes
63
Proteobacteria
Holds most sp
| Ex) E. coli and pestis (plague)
64
Firmicutes
Low GC
Endospores
Ex) b anthrecis, clostridium
C diff and fecal transplants that restore microbial diversity
65
Services bacteria perform for us
Gut microbes affect heart meds
Crime
Brain
Microbes allow energy to be salvaged from otherwise indigestible material
66
Microbiome
Communities of bacteria that live in and on our bodies
67
Obligate anaerobes
Oxygen is poisonous to them
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Obligate aerobes
Cannot survive without oxygen
69
Facultative anaerobes
Can shift metabolism between aerobic and anaerobic
70
Aerotolerant anaerobes
Not damaged by oxygen but do not conduct cellular respiration
71
Bacteria are (blank)
Natures recyclers
72
Energy
Photo or Chemo troph
73
Carbon
Hetero/auto troph
74
Some plants associate with bacteria to form cooperative nitrogen fixing root nodules. What are these called?
Chemoheterotrophs
75
Evolutionary reversal
3 generations, reverting back to prior generation (skip generation) and ancestral trait
76
Evolutionary convergence
Independently evolved traits subjected to similar selection pressures and may become superficially similar (wings)
77
Homoplasy
Similar traits in distantly related taxa generated by convergent evolution or evolutionary reversals
78
Tips
Taxa
79
Nodes
Splits in branches that indicate a division of one lineage into two
80
synapomorphy
derived traits shared among a group of organisms and viewed as evidence of common ancestry
81
history of evolutionary relationships among organisms or their genes
phylogeny
82
root
common ancestor of all the organisms in the tree
83
any species or group of species that we designate or name
taxon
84
any taxon that consists of an ancestor and all of its evolutionary descendants
clade
85
complete evolutionary history of life
tree of life
86
homologous
any features shared by two or more species that have been inherited from a common ancestor
87
example of homologous feature
vertebral column in vertebrates
88
parsimony
simplest explanation and requires fewest homoplasies
89
characteristics of viruses
not cellular, evolve independently, tiny size, rapid mutation rate, no fossils, diverse
90
negative sense single stranded RNA viruses
- RNA that is the complement of the mRNA needed for protein translation
- few genes
- RNA dependent RNA polymerase allows them to make complementary mRNA from negative sense RNA genome
- don't represent a distinct taxonomic group but instead a particular process of cellular escape
91
examples of negative sense single stranded RNA viruses
measles, mumps, rabies, influenza
92
positive sense single stranded RNA viruses
- already set for translation (no replication needed)
| - most abundant and diverse
93
examples of positive sense single stranded RNA viruses
diseases in crop plants, polio, hepatitis C, common cold
94
double stranded RNA virus
- evolved repeatedly from single stranded RNA ancestors
- not closely related
- infect tree of life
95
example of double stranded RNA virus
infant diarrhea
96
RNA retroviruses
- genomes composed of SS RNA evolved as escaped cellular components
- regenerate themselves by reverse transcription
- provirus= integrated retroviral DNA
- only infect vertebrates
97
examples of RNA retroviruses
HIV, cancer
98
double stranded DNA genome
- polyphyletic
- exchange of modules complicates history
- represent highly reduced parasitic organisms that have lost their cellular structure and ability to survive as free living
99
examples of double stranded DNA genome
smallpox and herpes
100
bacteriophages
viruses that attack bacteria
101
phage therapy
bacteriophage taken from stool and used to treat bacterial infections of the skin and intestines
102
bacteriophages provide the ability to
evolve and combat antibiotic-resisting bacteria
103
steps in transition from prokaryotic to eukaryotic cell
1) origin of a flexible cell surface (lost cell wall)
2) cytoskeletons devloped
3) phagocytosis
4) mitochondria and chloroplasts
104
origin of a flexible cell surface
- can grow larger
| - surface area to volume decreases but infolding increases surface area
105
cytoskeletons developed
- provide cell support
- move materials
- distribute chromosomes
106
phagocytosis
-loss of cell wall= ability to engulf other organisms in digestive vacuoles
107
mitochondria and chloroplasts
engulfed bacteria evolved into m and c, endosymbiosis
108
differences between archaea and bacteria/eukarya
- over half genes unique
- cell membrane (distinctive lipids)
- ether linkages- branched
109
endosymbiotic theory
- photosynthetic bacteria to chloroplasts
| - aerobic bacteria to mitochondria
110
certain organelles are the descendants of prokaryotes englufed, but not digested by early eukaryotic cells
endosymbiotic theory
111
primary endosymbiotic theory
engulfment of one cyanobacterium by a larger eukaryotic cell
112
support of endosymbiotic theory
size and shape, DNA circular, ribosomes (70s)
113
dinoflagellates
- most photosynthesize
- two flagella
- coral bleaching
114
- most photosynthesize
- two flagella
- coral bleaching
dinoflagellates
115
coral bleaching
live endosymbiotically in the cells of corals= reduces corals food when die
116
apicomplexans
- all parasites
| - ex) plasmodium (malaria) and toxoplasma (toxoplasmosis)
117
- all parasites
| - ex) plasmodium (malaria) and toxoplasma (toxoplasmosis)
apicomplexans
118
ciliates
- most are heterotrophic
- cilia used for locomotion
- ex) paramecium
- contractile vacuole
- hypotonic (more water out than in)
119
endocytosis
engulf solid food
120
contractile vacuole
expel water so doesn't explode
121
- most are heterotrophic
- ex) paramecium
- contractile vacuole
- hypotonic (more water out than in)
ciliates
122
diatoms
- unicellular or filaments
- photosynthetic (1/5 of worlds photosynthetic carbon fixation)
- symmetric (bilaterally or radially)
123
- unicellular or filaments
- photosynthetic (1/5 of worlds photosynthetic carbon fixation)
- symmetric (bilaterally or radially)
diatoms
124
radiolarians
- radial symmetry
- thin, stiff psuedopods
- elaborate skeletons
125
- radial symmetry
- thin, stiff psuedopods
- elaborate skeletons
radiolarians
126
foraminiferans
- shells of calcium carbonate
| - accumulate to form limestone
127
- shells of calcium carbonate
| - accumulate to form limestone
foraminiferans
128
heterolobosean
- ex) Naegleria fowleri (brain eating amoeba)
| - amoeboid body form
129
Euglenids
- have flagella
| - some photosynthetic
130
- have flagella
| - some photosynthetic
Euglenids
131
- ex) Naegleria fowleri (brain eating amoeba)
| - amoeboid body form
heterolobosean
132
kinetoplastids
- parasites
- ex) trypanosoma
- disease: chagas, sleeping sickness
133
- parasites
- ex) trypanosoma
- disease: chagas, sleeping sickness
kinetoplastids
134
loboseans
- phagocytosis
- no flagella, cilia
- have lobe shaped pseudopods to move
135
- phagocytosis
- no flagella, cilia
- have lobe shaped pseudopods to move
loboseans
136
plasmodial slime molds
- no plasma membrane
- mass of cytoplasm, many nuclei
- streams over substrate- eating
- transforms into fruiting structures
- sporangia hold haploid spores
137
- no plasma membrane
- mass of cytoplasm, many nuclei
- streams over substrate- eating
- transforms into fruiting structures
- sporangia hold haploid spores
plasmodial slime molds
138
cellular slime molds
- retain plasma membrane, individuality
| - haploid
139
- retain plasma membrane, individuality
| - haploid
cellular slime molds
140
a multicellular (blank) spore forming organism that gives rise to a multicellular (blank) gamete forming organism
diploid (2n), haploid (n)
141
the (blank) is the multicellular diploid generation
sporophyte
142
the (blank) is the multicellular haploid generation
gametophyte
143
cells in the sporophyte divide (blank) to produce haploid spores
meiotically
144
spores germinate and divide meitically to produce the (blank)
haploid gametophyte generation
145
multicellular, diploid, spore producing stage gives rise to (blank)
a multicellular, haploid, gamete producing stage
146
specialized cells of the diploid spore producing organism (sporophytes) divide (blank) to produce (blank)
meiotically, four haploid spores
147
gametes produced by the (blank) must fuse to form a new sporophyte generation
(gametophyte generation)
148
competition
- and -, both harmed
149
predation
+ and -, one benefits, one harmed
150
mutualism
+ and +, both benefit
