bio1120 exam 2 Flashcards
(112 cards)
1
Q
chemical evolution
A
reaction of inorganic chemicals to produce simple organic chemicals, that later polymerized into macromolecules
2
Q
chemical evolution steps
A
- abiotic synthesis of organic molecules
- join into macromolecules
- package into protocells
- origin of self replicating molecules
3
Q
4 requirements for chemical evolution
A
- little to no free oxygen
- source of energy (light/radiation)
- chemical building blocks (water, gases)
- time
4
Q
what were the first protocells
A
clay armored bubbles, fluid filled vesicles with membrane
5
Q
what did first protocells have
A
- metabolism
- could replicate/ simple reproduction
- maintained internal envt
6
Q
what did prebiotic earth give rise to first
A
RNA which evolved from natural selection favoring RNA that self replicates better
7
Q
what was RNA the template for
A
DNA
8
Q
how is bacteria different from archea
A
bacteria has a peptidoglycan cell wall
archaea has no cell wall and membranes with phospholipid
archaea is more similar to eukaryotes
9
Q
what do bacteria and archaea have in common
A
circular chromosomes
unicellular and prokaryotic
10
Q
what are the 3 shapes of bacteria
A
bacillus, coccus, spirulum
11
Q
gram positive
A
thick cell wall of peptidoglycan
12
Q
gram negative
A
2 membranes with peptidoglycan between them
13
Q
pili
A
long appendages used to pull together bacteria for conjugation
14
Q
fimbrae
A
hair like structures that help stick
15
Q
endospores
A
protective covering on bacteria that helps them go dormant
16
Q
flagella
A
whip like appendage that help bacteria move
17
Q
chemotaxis
A
response to chemical stimulus
ex: smell
18
Q
nucleoid
A
string of chromosomes
19
Q
plasmids
A
circular dna seprate from nucleoid
20
Q
photoautotroph
A
makes its own energy and carbon from sun
21
Q
chemoautotroph
A
makes its own energy and carbon from inorganic chemicals such as sulfur or methane
22
Q
photoheterotroph
A
can do photosynthesis or assimilate organic material heterotrophically ex:euglena
23
Q
chemoheterotroph
A
obtains energy and carbon from eating organic compounds
24
Q
nitrogen fixation
A
converting nitrogen gas from atmosphere to a digestible form.
nitrogen fixing bacteria live in root nodules.
25
obligate aerobe
requires oxygen for life
26
obligate anaerobe
killed by oxygen
27
facultative anaerobe
can live without oxygen but grows better with it
28
biofilm
surface coating layer of bacteria
29
what gene transfer do bacteria use to share genetic info
horizontal gene transfer
30
3 mechanisms of horizontal gene transfer
conjugation, transduction, transformation
31
conjugation
bacteria attach through pili and share plasmids
32
transformation
bacteria pick up dead DNA from environment
33
transduction
bacteria get DNA from viruses carrying DNA from other cells
34
what has genes for resistance to antibiotics
plasmids
35
spirochetes
1. free living
2. gram negative
3. heterotrophs
4. pathogenic parasites: syphilis, lime disease
36
actinobacteria
1. chains of cells
2. gram positive
3. can produce antibiotics (streptomyces)
4. tuberculosis, leprosy
37
cyanobacteria
1. photosynthetic
2. source of oxygen and food for aquatic life
3. algae
38
proteobacteria
1. gram negative
2. elaborate morphology
3. pathogenic: cholrea, ghonorrhea, dysentery
39
crenarchaeota
only lives in extreme environments
40
euryarchaeota
live in every habitat and produce methane
41
how are prokaryotes used in research
and technology
1. DNA tech (crispr, cloning, pcr)
2. bioremediation (degrading toxins)
3. biodegradable plastic
4. biofuel
42
what are bacteria that cause disease called
pathogenic
43
where do pathogens affect tissues
entry points (wounds, pores, mucous membrane)
44
germ theory of disease
diseases are caused by microogranisms
45
virulence
ability to cause disease, can be heritable
46
how do bacteria enter
1. release enzymes that digest away the
complex sugars that join our epithelial layers
2. release enzymes that can dissolve blood clots
47
antibiotics
molecules that kill bacteria, target peptidoglycan
48
malacidins
antibiotics released by bacteria that kill gram positive pathogens
49
ecological roles of prokaryotes
1. decomposers
2. symbionts
3. parasites
4. commensals
50
how are eukaryotes different from bacteria
1. nucleus
2. membrane bound organelles
3. cytoskeleton
4. reproduce through sexual or asexual reproduction
51
what were the earliest eukaryotes
protists with
1. single celled nucleus
2. mitochondria
3. cytoskeleton
4. no cell wall
52
what is a protist
eukaryotes that aren't plants animals or fungus
53
what did later eukaryotes have
1. photosynthesis
2. sexual life cycle
3. multicellular
54
endosymbiotic theory
mitochondria and plastids were prokaryotic endosymbionts that got swallowed by a host cell
55
endosymbiosis
symbiotic relationship where one organism lives inside of another
56
who discovered endosymbiotic theory
Dr. Lynn Margulis
57
how did eukaryotes evolve
1. Ancestral prokaryote
underwent infolding of plasma
membrane = nucleus and
endomembrane system
2. It engulfed aerobic bacterium
and became a host
3. Engulfed aerobic bacterium
became mitochondria
4. some engulfed photosynthetic bacteria which became plastids
58
evidence for endosymbiosis theory
1. membranes are double
2. mitochondria and plastids have their own circular DNA
3. mitochondria and plastids have their own ribosomes
4. they can multiply like bacteria
59
secondary endosymbiosis
occurred when eukaryotic algal cells were ingested by heterotrophic eukaryotes
60
what organisms underwent secondary endosymbiosis
red and green algae
61
evidence for secondary endosymbiosis
1. cyanobacteria are gram negative
2. plastids in red and green are similar
3. double membranes.
4. transport proteins are homologous to proteins in the inner and outer membranes of cyanobacteria
62
what were the first multicellular life forms
colonies of connected cells with little to no differentiation
63
did multicellular organisms (plants, animals, fungi) develop multicellularity dependently or independently
independently
64
what protist do animals share DNA with
choanoflagellates
65
what protein plays a key role in how animal cells attach to eachother
cadherin
66
what was a key step of transitioning into multicellularity
proteins finding new ways of rearranging
67
excavata
1. many are parasites
2. 3 clades: parabasalids, diplomonads,
and euglenozoans
68
SAR
1. 3 large clades: Stramenopila, Alveolata, and Rhizaria
2. photosynthetic
3. found in limestone of pyramids
69
Archaeplastida
plants, algae, volvox
70
Unikonta
animals, slime mold, fungi, amoebas with lobes
71
what diseases can parasitic protists cause
malaria, irish potato famine, and amoebic dysentery
72
phytoplankton
photosynthetic organisms that drift with the currents
73
algal blooms
When algae reach high densities in aquatic environments. Toxins many fish and build up in shellfish. ex: red tide
74
ecological roles of protists
1. decomposers
2. photosynthesis
3. population control of bacteria
75
what protist is red tide caused by
dinoflagellates
76
how did plants evolve to live in a dry environment
1. prevented water loss from cells
2. had to transport water through tissues
3. had to learn how to stay upright
77
are plants monophyletic or polyphyletic
monophyletic
78
what did land plants evolve from
green algae
79
why did plants evolve to live on land
more CO2 + sun
80
what are derived traits of plants
alternation of generations, spores in sporangia, cuticle, apical meristems
81
alternation of generations
plants spend half their life cycle in a haploid gametophyte phase and half in a diploid sporophyte phase
82
what are the reproductive structures in spore bearing plants
archegonia and antheridia
83
what do zygotes in land plants from
embryos
84
how do spore plants reproduce in dry conditions
walled spores in sporangia, Spore walls contain sporopollenin, which makes them resistant to harsh environments
85
apical meristem
regions of cell division at the tips of roots and shoots. can divide throughout a plants life
86
cuticle
layer of waxy, watertight sealant that covers above ground parts of plant.
keeps water in but keeps CO2 out
87
stoma/stomata
pores surrounded by specialized guard cells that open and close pores. used for gas exchange of CO2 and O2
88
4 major plant groups
1. bryophytes (non vascular)
2. pteridophytes (seedless vascular)
3. gymnosperms
4. angiosperms (flowering plants)
89
rhizoids
root like structures on non vascular plants that keep them anchored
90
what are the benefits of the vascular system
allows plants to grow taller and transports nutrients and water
91
lignin
Extra-strong polymer that helps support erect plant tissues. defining feature of vascular tissue.
92
xylem
transports water and minerals
93
phloem
transports photosynthesis products
94
tracheids
tube shaped cells in xylem
95
purpose of roots
anchor vascular plants and enable them to absorb water and nutrients from the soil
96
purpose of leaves
primary photosynthesis organ
97
how many times did cuticle, stomata & tracheids evolve
once
98
convergent evolution
water-conducting cells evolved independently in mosses and vascular plants
99
what 2 plant groups produce seeds
gymnosperms and angiosperms
100
why does pollen give seed plants an advantage
it helped plants adapt to dry environments. they no longer need water for fertilization.
101
sporopollenin
protective coat around pollen grains
102
what's in seeds
embryo and nutrients from mother. surrounded by a protective coat
103
why do seeds have an advantage
they protect the embryo, make it easy to spread far, and can lay dormant for years
104
what is the most dominant plant
angiosperms
105
Monocots
1. flower parts in 3
2. one cotyledon
3. Leaves have parallel veins (ex: grass)
105
Eudicots
1. Flower parts in fours or fives
2. two cotyledons
3. Leaves have branching veins (ex: oak trees)
106
what evolved after stamens and carpels
petals and sepals
107
Pollination
the transfer of pollen from one plant’s stamen to another plant’s carpel
108
types of gymnosperms
pine, spruce, fir, hemlock, ginkgoes
109
what is a ginkgo
a tree with fan shaped leaves that's extinct in the wild and produces disgusting fruit. only one species
110
2 classes of angiosperms
monocots and eudicots
111
why do fruits give angiosperms an advantage
they attract more animals who spread their seeds
