midterm Prep Flashcards
(128 cards)
1
Q
Characteristics of living organisms (3)
A
- Grow/survive
- Reproduce
- Heredity
2
Q
How do organisms achieve processes (4)
A
- Organization of cells
- ATP
- Synthesis/degredation of molecules
- Common nucleic code
3
Q
Protocells
A
Lipids/amino acids
Could form membrane-bound vesicles
4
Q
What did Millar’s experiment show
A
Amino acids, sugar, and nucleic acids generated spontaneously from earth’s early atmosphere- disfavoured
5
Q
Most favoured current theory of beginning of life
A
Alkaline deep sea vents
6
Q
Order of evolution from early earth rough
A
- prokaryotes
- photosynthetic
- oxygen
- eukaryotes
- multicellular cells
- colonization of land by plants
- flowers
7
Q
How do you define a species
A
Biologicallu
Morphological
Ecologically
Phylogenetically
Prokaryotes
8
Q
Biological species
A
Members can interbreed and produce viable fertile offspring
9
Q
Morphological species
A
Members have common structures
10
Q
Ecological species
A
Same niche similarities
11
Q
Phylogenetic species
A
Nucleic acid similarities
12
Q
Prokaryotic species
A
Strains with common biochemical properties
13
Q
Why are viruses not organisms (4)
A
- Lack cellular structures
- Do not grow
- Do not respond to external stimuli
- No independent metabolism
14
Q
Viral replication cycle
A
- Release capsid into host cell
- Host enzymes replicate viral proteins and mRNA
- Host makes more capsids
- Self assemble into new viral particles
15
Q
Biological characteristics of prokaryotes
A
- 1 DNA circular chromosome
- no nucleus
- no membrane bound organelles (except photosynthesizers)
- no cytoskeleton
- small ribosomes
- asexual reproduction
16
Q
Traits of being microscopically small
A
- fast reproduction
- easy dispersal
- high sensitivity to environment (low SA to V ratio)
- high rate of living
- affects water
- water is viscous
- restricted mobility
17
Q
High rate of living
A
- SA determines absorbtion and excretion ability
- Low ratio = more nutrients per cell
- High ratio = less nutrients per cell
More nutrients=faster metabolism = shorter life span
18
Q
Why is water viscous for microorganisms
A
Energy expenditure per unit of mass moved
Low ratio of SA to V = more friction per unit mass
High ratio = less friction per unit mass
19
Q
Implications of restricted mobility in microorganisms
A
“Spacial and temporal heterogeneity in nutrients and environment is critical to prokaryotic activity”
- limited movement = dependent on changing environments to deliver nutrients
20
Q
Uptake of nutrients for prokaryotes
A
Via Cell wall: small molecules only = extracellular hydrolysis to break down larger
Diffusion through extracellular matrix
21
Q
Photoautotrophs
A
Light
Inorganic Carbon
22
Q
Photoheterotroph
A
Light
Organic C source
23
Q
Chemoautotroph
A
Chemical
Inorganic C
24
Q
Chemoheterotroph
A
Chemical
Organic C
25
Prokaryotic Reproduction (fission)
1. Duplication of chromosome
2. Cell elongation
3. Septum forms
4. Cell divides
26
Phases of prokaryotic growth
1. Lag
2. Log
3. Stationary
4. Death
27
Genetic variation prokaryotes causes
- Mutation
- Rapid generation time
- Gene flow
28
ARCHEA vs bacteria
- rRNA different
- Cell wall composition different
Bacteria…
- endospores
- disease
- diverse in energy acquisition
- Phospholipid bilayer
- peptidoglycan
Archea…
- branched lipid tails
- some tails link = monolayer, not bilayer
- pseudomurein not peptidoglycan
29
Chemoheterotrophs - saprobes
“Recyclers/decomposers’
- waste is used by another organism
- food production
- lead to antibiotics
30
Chemoheterotrophs - symbionts
Rumen - 4 chambered stomach of cows
- break down cellulose
- cow regurgitates and enters new chamber
- regular digestion
Soil - Fabaceae and achtinorhizal
- nodes on plant roots
- assists in nitrogen fixing
31
Chemoheterotrophs - parasitic / pathogenic
Cause illness
32
Cyanobacteria
Chlorophyll A
- can fix nitrogen
- symbiotes (many)
- store C,P,N
33
Chemoautotrophs types
1. Nitrifiers
2. Iron oxidizers
3. Sulfur oxidizers
4. Methanotrophs
5. Methanogens
34
Nitrifiers
NH4 —> NO3
35
Iron Oxidizers
Fe2+ —> Fe3+
36
Sulfur oxidizers
S —> SO2-
37
Methanotrophs
CH4 —> CO2
38
Methanogens
H2 + CO2 —> CH4 + H2O (chemoautotrophs)
H2 + acetate (C2H3O2-) —> CH4 + H2O (Chemoheterotrophs)
ONLY anaerobic respiration
Natural gas (CH4) methane
Greenhouse gas
39
What kingdoms make up Eukarya
- Plants
- Animals
- Fungi
- Protists
40
Structure differences - Prokaryotes vs eukaryotes
Prokaryotes
- smaller
- no nucleus
- no membrane bound organelles
Eukaryotes
- larger
- nucleus
- Membrane bound organelles = compartimentalized functions
Similarities
- plasma membrane
- Cytoplasm
- Ribosomes
- cytoskeleton
41
What part do all prokaryotic and eukaryotic cells have?
Plasma membrane
42
How does a typical prokaryotic cell compare in size to a eukaryotic cell?
Smaller by 100x
43
Prokaryotic cells are surrounded by a ________ membrane and have _______, ________, and ________, like eukaryotic cells. They also have ________ walls and may have a cell __________ . Prokaryotes have a _________ large chromosome that is not surrounded by a _________ membrane. Prokaryotes may have _________ for motility, __________ for conjugation, and __________ for adhesion to surfaces.
- plasma
- DNA
- cytoplasm
- Ribosomes
- cell
- capsule
- single
- nuclear
- flagella
- pilli
- fimbriae
44
What are fimbriae
Finger like projections
Allow for adhesion
“Short pilli”
45
Function of internal membranes in eukaryotes
- organization
- discrete processes
- increased SA for respiration
- nuclear membrane = transcription separate from translation
46
Benefit of having a nucleus
Transcription and translations peerage = post transcriptional modification of mRNA
47
Function of having paired chromosomes
Mitosis and meiosis = sexual reproduction
48
Why have no rigid cell wall
Phagocytosis
49
Benefit for of cytoskeleton
Organization and transport
50
Function of larger ribosomes eukaryotes
Eukaryotes = larger = more complex requirements
51
Function of complex flagella
Better cell motility
52
What makes eukaryotes gene structure more complex
introns and mobile genetic elements
53
Benefits of having introns
- post transcriptional modification of mRNA
- alternative splicing = different proteins via exon combos
54
Benefits of mobile genetic elements
- transposons (copy and paste)
- plasmids (cut and paste, prokaryotes)
55
What was the major development towards evolution of eukaryotes
- Anaerobic respiration
- photosynthesizers
- aerobic respiration
- oxygen 100%
56
Why did membrane bound organelles originate
Aerobic respiration / photosynthesis
57
Why did nucleus originate
Compartmentalize and protect dna
58
Serial endosymbiosis theory
1. Prokaryote + Aerobic bacteria = amoeboid with mitochondria
2. Develop flagella = animals
3. flagella + cyanobacteria = plants
59
What does serial endosymbiosis theory provide
Theory explaining presence of membrane bound organelles
60
Theories of origin of nucleus
1. Autogenous
2. Endosymbiosis
61
Autogenous hypothesis of nucleus
Infolding of plasma membrane (bacterial) -> nucleus and endo reticulum
1. Loss of cell wall
2. Inward folding
3. DNA surrounded by internal membranes
62
Endosymbiosis theory of nucleus
Archeal host cell endocytosed Gram negative bacterium
63
Origin of photosynthetic eukaryotic cell by Autogenous and ER membrane evolution (continuation from non photosynthetic)
1. Phagocytosis of precursor to mitochondria
2. Phagocytosis of precursor to chloroplast
64
Current theory of evolution of nucleus and mitochondria
Autogenous followed by serial endosymbiosis
65
Evidence of serial endosymbiosis
- mitochondria resemble bacteria
- chloroplasts and Cyanobacteria have chlorophyll a and produce oxygen
66
Darwinian perspective of evolution was developed using what type of observations
Morphological of eukaryotic macro organisms
67
Morphological observations of macro organisms included
- heritable variation
- phenotypic variation
** mutation and sexual recombination
68
Example of how horizontal gene transfer enhanced diversity among tree of life
Serial endosymbiosis
69
How did Heritable genetic variation occur
- switch from endocytosis to exocytosis
- fitness
- retention of cell, not digestion (mitochondria)
- efficient ATP genes favoured
1. Allelic variation
2. Election pressures
3. Favoured allele more common
70
Benefits of asexual reproduction
- no mates
- limited resources
- faster replication
- no genetic variation
- nursing effect
71
Benefits of sexual reproduction
- genetic diversity
- dominant and recessive traits
- alternation of generations
- polyploidy (potential)
72
Speciation mechanisms in eukaryotes arising from initial diploidy
1. Hybridization
2. Autopolyploidy
3. Allopolyploidy
73
Hybridization
N+N
New species after 1 generation
Humans=selection force
74
Autoployploidy
2N x 2
Double chromosomes
75
Alloploidy
(N+N) x 2
2+ sets of chromosomes from more than 1 species
Hybrid + Autoploid
76
Zygotes meiosis most fungi
1. Gametes = haploid
2. Fertilization —> Zygote = diploid
3. Mitosis
Zygote undergoes meisosis
77
Plants meiosis (alteration of generations)
1. Gametes = haploid (gametophyte)
2. Fertilization = diploid
3. Mitosis = diploid (sporophyte)
4. Mitosis (spores)
Multicellular and diploid phases
78
Animal gemetic meiosis
1. Haploid
2. Diploid
Gamete produced from meiosis
79
Benefits of diploidy
- sexual reproduction
- subtle variation
80
benefits of expanded diploid phase
- more time for selection
- germ line separation
81
Germ Line
Sex cells
82
Germ line separation
Separation of germ line cells from somatic cells
(A mutation that happens in a somatic cell after zygote created can not be passed to the zygote)
83
Reduced haploid phase
Decreases time for fatal mutations to single allele
84
protists lack what
Key characteristics of plants animal or fungi
Ex. Algae
85
Algae lack what
Roots, stems, leaves, vascular tissues, cuticle
86
How is chlorophyll an example of exaltation?
Only difference from hemoglobin is it has Mg not Fe
87
How do aquatic algae parallel land plants
- primary producers
- competition
- complex food webs
- structural support
- decomposition
- diversity
88
How did algal diversity occur from heteotrophic protist groups
Multiple SEQUENTIAL endosymbiosis events
1. Primary endosymbiosis (cyano A) —> 2 membranes
2. Secondary (early heterotrophic [nucleus and mito]) —> 3 membranes
89
Ecology of red algae
- warm and cool marine waters
- red dominate marine
- on rock / other algae
- antiherbivore terpenoids
90
Structure red algae
- no flagella
- mostly multicellular
- branched fillaments
- mucilage secretion
- cell walls w cellulose and calcium carbonate
91
How does reg algae contribute to coral reefs
Red algae = calcification of cell walls
Calcium carbonate
Crucial for coral
92
Chloroplasts in red algae contain what pigment
Chlorophyll a and c
phycobilins
Carotenoids
93
Asexual reproduction of red algae
Monospores diploid
94
Sexual reproduction of red algae
Alternation of generations
3 multicellular stages
- 1 haploid
- 2 diploid
95
Why did red algae evolve 2 diploid phases
Produce self replicating spores = more
96
How was alternation of generations evolved (general order across tree of life)
With complexity of organisms
Asexual —> sexual —> zygotes meiosis —> alternation of gens
97
Theory of how alternation of generations evolved
- mutant cell in diploid phase of mitosis (haploid cell) doesn’t fission
- undergoes mitosis becomes gametes
- fertilization = gametes
- mutant —> mitosis = diploid reproduction
- meiosis
- self replication
- gametes
Fertilization
Self replication
Repeat
98
Why evolve to be mostly in diploid phase
- more genetic information
- more genetic diversity
- preserve mutations
- polyploidy potential
- more meiosis = more cells produced = more chance to meet mate
99
Selection pressure for diploid of red algae
Adaptation to turbulent water or dryish places
- flagella useless
- increased gamete production favoured
100
Green algae
- mostly freshwater
- soil snow trees
-
101
Green algae structure
- chlorophyll a and b
- 2 flagella
102
Fungi major features
- mainly terrestrial
- cell wall
Unicellular or hyphal
- spores
- chemoheterotrophs
- catabolic enzymes
- NO FLAGELLA GAMETES
103
Red queen hypotheis
Plant evolves to defend fungi
Fungi evolves new compound to counteract defense
Can lead to speciation
104
Yeast reproduction
Asexual; budding
Sexual: fertilization (during substrate depletion)
105
Where does yeast spend most its life cycle
Haploid phase
106
What does it mean that some fungi are facultative anaerobes
Can switch between aerobic respiration and fermentation
107
Fertile Crescent
Grapes places with wheat by accident’
Spores went on to grapes (yeast0
Spores fermented grape sugar
Made wine
108
Hey Hal web is called
Mycelium
109
Implications of being small and filamentous (hyphae)
- rapid growth
- large SA:V ratio
- interconnects the hotspots
110
Fungi acquire nutrients how
- uptakes small molecules
- larger ones broken down in extracellular matrix via enzymes
- transport needed nutrients via hyphae where needed
111
Fungi reproduction
Asexual; spores
Sexual; fusion of cells from hyphae
112
Fungi life cycle
- diploid —> gamete
- assexual reproduction
- new mycelia
- attach
- form new diploid where attached
113
Dominant stage fungi life cycle
Dikaryotic
(Cytoplasmic fusion)
114
Rapid evolution of viruses is do to
- rapid reproduction in host cells
- large progeny
- antigenic shift
115
Why are viruses bad to humans
- disease
- population decline via colonization to areas without immunity
- bioterrorism weapon
- human food supply
116
In zygotic meiosis of fungi, when does cytoplasmic fusion and nuclear fission occur
Mating —> cytoplasmic fusion —> nuclear fission —> zygospore
117
What promotes sexual reproduction fungi
- resource depletion
- harsh environmental conditions
- mate detected
118
Why is sexual reproduction more stable for fungi but less common
Diploid is most stable form, can’t reproduce as rapidly
119
Why are fungi more important than others in decomposition in ecosystems
- hyphae transport nutrients from far away
- do not need water source near by = dry rot
- can make specific enzymes to decay larger molecules ie wood
120
Compare and contrast fungal and vascular plant reproduction by describing three distinctive features of the genetics and lifecycles of the Kingdom Fungi
FUNGAL
- spores (asexual reproduction)
- unicellular diploid phase is protective and dormant
- prolonged dikaryotic phase due to separated cytoplasmic fusion and nuclear fission stages
121
Euglenoids
Group of flagellates
- photosynthetic and heterotrophic
Therefore, facultative heterotrophs
122
Chlorophyll A vs B vs C
A: Chloroplast endosymbiosis, all plants and algae
B: Secondary endosymbiosis of euglenoids (green)
C: Secondary endosymbiosis of dinoflagellate (red)
Red Dino’s did not C the meteor
123
Evidence some euglanoids gained photosynthesis via secondary endosymbiosis
Have chlorphyll B
Triple layer membrane
Heterotrophic tendencies
124
Are lichens really symbiotic
fungi: gains organic carbon source
Algae: gains protection, water source
125
Structure of lichen and function
OUTSIDE
- dense fungi: protection from extreme light and insects/predators/harsh conditions
- algae: organic carbon source. Photosynthesis
- spongey fungal layer (medulla): storage for water and air
- lower cortex: formation and attachment of rhizines
126
Rhizines
Anchors body of lichen to substrate . Don’t absorb
127
How do lichens acquire carbon and sulfur
Carbon: algae via photosynthesis
Sulfur: via rainfall from atmospheric deposits
128
3 types of sexual reproduction
Conjugation
Fertilization
Alternation of generations
