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BIO exam 2 Flashcards

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1
Q

What type of speciation has populations that are separated by a physical barrier?

A

Allopatric Speciation

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2
Q

What is a defining characteristic of allopatric speciation?

A

Geographic isolation

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3
Q

Which of the following is an example of allopatric speciation?

White-tailed antelope squirrel & Harris antelope squirrel
Lake Victoria Cichlid
Whiptail lizards
Midas Cichlid
Cope Gray Treefrog & Gray Treefrog

A

White-tailed antelope squirrel & Harris

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4
Q

What is sympatric speciation?

A

A species that live in the same area

No physical barriers; new species form within the range of existing species (in direct contact)

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5
Q

In what ways could sympatric speciation occur?

A

May occur due to competition driving segments of the population to adapt to specialized niches

May occur due to niche divergence or resource partitioning

May be driven or reinforced by sexual selection

May also occur as a result of hybridization and polyploidy

Autopolyploid: due to nondisjunction (parents are same species)

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6
Q

What type of selection is involved with sympatric speciation?

A

Disruptive (divergent) selection

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7
Q

What are some examples of sympatric speciation?

A

Lake Apoyo, Nicaragua: Midas Cichlid
Lake Victoria Cichlid
Cope’s Gray Treefrog & Gray Treefrog

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8
Q

What type of speciation occurs when a new species is formed when two species hybridize?

A

Allopolyploid

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9
Q

What type of speciation occurs in neighboring populations that may evolve into distinct species?

A

Parapatric speciation

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10
Q

What are the five patterns of speciation related to time?

A

anagenesis
cladogenesis
gradualism
punctuated equilibria
extinction

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11
Q

What characteristic applies to both anagenesis and cladogenesis?

A

Speciation

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12
Q

What are two speculations for the origins of the universe?

A

Big bang
orgin of the earth

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13
Q

Which of these is the correct from oldest to most recent Era?
Precambrian, Cambrian, Paleolithic, Cenozoic
Cenozoic, Mesozoic, Paleozoic, Paleolithic
Cambrian, Precambrian, Paleozoic, Mesozoic
Precambrian, Paleozoic, Mesozoic, Cenozoic
Paleozoic, Precambrian, Mesozoic, Jurassic

A

Precambrian, Paleozoic, Mesozoic, Cenozoic

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14
Q

What evidence is consistent with the Big Bang Theory?

A

Expansion of the universe

Abundances of He, 𝐷_20, Li

Cosmic microwave background radiation

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15
Q

What evidence of the early conditions on Earth, are present in the reducing atmosphere?

A

Water Vapor
H, 〖𝑁𝑂〗_𝑥, 〖𝐶𝐻〗_4, 〖𝑁𝐻〗_3, 𝐻_2S, 〖𝐶𝑂〗_2
No free 𝑂_2
No Life

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16
Q

Put the following events in sequence:1. anaerobic prokaryotes evolve2. O2 present3. cyanobacteria evolve4. protocells or liposomes form, surrounding amino acids, RNA & other chemicals5. abiotic synthesis of macromolecules

A

5, 4, 1, 3, 2

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17
Q

Which of the following is NOT something that was found on the early earth (4.6BYA):
A. water vapor
B. CO2
C. small elements (H, N)
D. NH3
E. O2

A

E. O2

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18
Q

What are early compounds that were floating around in what condensed into pools of water and water vapor?

A

Primordial soup

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19
Q

What are protobionts?

A

Kind of molecule to form things that sort of resemble living cells but are not actually living

Precursors

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20
Q

What are the characteristics of early living cells?

A

Metabolism
Self-replicating molecules
Plasma membranes

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21
Q

What are the characteristics of self-replicating molecules: RNA?

A
  1. Heat + coenzymes + phosphate chains = single strands of RNA
  2. Ribozymes
    RNA based on catalysts: able to make short copies of themselves; a sequence of bases that can make a copy of itself
  3. NS on ribozymes
    - Copying introduces errors
    - More stable and faster copying variants would be more numerous (more efficient)
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22
Q

Ribozymes (choose all that are correct):A. are enzymes
B. are made of single-stranded RNA
C. can self-replicate
D. can digest molecules
E. are more stable than DNA

A

A. are enzymes
B. are made of single-stranded RNA
C. can self-replicate

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23
Q

What can you tell me about Plasma Membranes?

A

Synthesized abiotically: happens spontaneously using non-living organisms or non-living elements in the environment

Phospholipids: molecules that have a phosphate head that is hydrophilic and have a fatty acid tail that is hydrophobic

Amphipathic: hydrophilic and hydrophobic

Liposomes: sacs form spontaneously from phospholipids or vesicles

Protocells or protobionts: membrane sacs surrounding macromolecules (RNA/DNA) and metabolic agents

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24
Q

What can you tell me about Plasma Membranes?

A

Synthesized abiotically: happens spontaneously using non-living organisms or non-living elements in the environment

Phospholipids: molecules that have a phosphate head that is hydrophilic and have a fatty acid tail that is hydrophobic

Amphipathic: hydrophilic and hydrophobic

Liposomes: sacs form spontaneously from phospholipids or vesicles

Protocells or protobionts: membrane sacs surrounding macromolecules (RNA/DNA) and metabolic agents

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25
What can you tell me about the first prokaryotes?
~3.8 BYA Membrane-bound, self-replicating sacs of DNA and other organic molecules  Lack No O₂; anaerobic reaction, fermentation (energy pathways)  ~3.5 BYA- photosynthesis evolved in anaerobic prokaryotes ~2.5 BYA- O₂ accumulated Cyanobacteria: transformed the atmosphere O₂ rich atmosphere Aerobic respiration No further chemical origin of living cells Ozone layer (O₃)
25
What can you tell me about the first prokaryotes?
~3.8 BYA Membrane-bound, self-replicating sacs of DNA and other organic molecules  Lack No O₂; anaerobic reaction, fermentation (energy pathways)  ~3.5 BYA- photosynthesis evolved in anaerobic prokaryotes ~2.5 BYA- O₂ accumulated Cyanobacteria: transformed the atmosphere O₂ rich atmosphere Aerobic respiration No further chemical origin of living cells Ozone layer (O₃)
26
What are stromatolites?
Build up in layers that form rocks that form fossils
27
What characteristics are involved when comparing mitochondria & chloroplasts to bacteria?
Very similar in size and structure Have circular DNA that is replicated independently of ‘host’ DNA Self-replicate by similar cell division M & C have their own ribosomes which resemble those of bacteria more than eukaryotic ribosomes Many antibiotics that kill or inhibit bacteria inhibit M & C protein synthesis Woese and Doolittle Contemporary endosymbiotic relationships
28
How did Woese determine the relationships among the 3 domain lineages:
sequenced small subunit ribosomal RNA
29
What made the evolution of eukaryotic cells possible by the origin of eukaryotic organelles?
Endosymbiosis
30
Endosymbiosis has resulted in…
The origin of mitochondria and chloroplasts The evolution of eukaryotic cells Horizontal gene transfers
31
A chimera in biology is…
an organism which has cells containing DNA from different individuals (of the same species, or of different species)
32
What are the 3 domains?
Archaea Bacteria Eukarya
33
Put the 3 domains in evolutionary order from the most primitive ancestral domain to the most recently evolved domain.
Bacteria, Archaea, Eukarya
34
What are the 6 kingdoms?
Archaebacteria, Eubacteria, Protists, Fungi, Plantae, Animalia
35
Which of the 6 kingdoms are prokaryotes?
Archaebacteria, Eubacteria
36
Which of the 6 kingdoms are eukaryotes?
Protists, fungi, plantae, animalia
37
What are fossils?
Mineralized proof of life (evidence of formerly living life)
38
What is the geologic time scale?
Transition periods based on sequences of fossils in sedimentary rocks
39
What are 3 examples of the geologic time scale?
Cenozoic (65 MYA-present; age of mammals) Mesozoic (240-65 MYA; age of reptiles) Paleozoic (570-240 MYA; age of invertebrates)
40
What are variants of elements with differing numbers of neutrons?
Radioisotopes
41
What is radio-isotope dating?
Compare the ratio of radioisotopes/stable isotopes in a sample with that of a similar living organism
42
What are the other types of radiometric dating of fossils?
Carbon dating Potassium-Argon dating Uranium-lead dating
43
What is taxonomy?
The science of naming things
44
What is the classification of organisms?
Hierarchical, attempts to reflect evolutionary relationships
45
What is the hierarchal order of classification of organisms?
Domain, Supergroup, Kingdom, phylum, class, order, family, genus, species
46
What are phylogenies?
Hypothesis: evolutionary history of relatedness of taxa
47
How are phylogenies constructed?
Based on shared characteristics Morphology & homologous structures Genetic structure Biochemistry
48
What is comparative DNA or biochemistry?
Similarities are greatest among most closely related species
49
What is a clade?
A grouping of related organisms
50
What is a cladogram?
A diagram that shows clade arrangements
51
What is a phylogenetic tree?
A diagram that shows the evolutionary history and evolutionary relatedness
52
When constructing a phylogenetic tree (or cladogram), how do scientists narrow down the possible configurations to the most likely candidates? By:
A. the principle of parsimony B. the fewest evolutionary events or changes required
53
What are the characteristics of cladistics or phylogenetics?
Uses shared homologous traits to construct diagrams The polarity of a trait: i.e., traits that are plesiomorphic (primitive or ancestral) vs apomorphic (derived) Clades grouped according to common ancestry Nested
54
What are shared ancestral traits?
Symplesiomorphy
55
What are synapomorphies?
Shared derived (recently evolved) traits due to common ancestry
56
What are shared characteristics that are analogous, evolved independently 2 or more times?
Homoplasies
57
What is paraphyletic?
Does not contain all descendants
58
What is polyphyletic?
More than one ancestor
59
When describing a group of animals, you speak about an ancestral species and some but not all of its descendants. This is an example of a
paraphyletic group
60
What is Occam’s razor?
The explanation that relies on the least assumptions is most likely correct
61
What is a phylogram?
Geological time is used to determine the relative distance of the branches
62
What are some general characteristics of bacteria?
Microorganisms are 0.5 to 2.0 micrometers in size Prokaryotic, single cells DNA: single circular chromosomes & small circular plasmids Lack membrane-bound nucleus and organelles
63
What are the different prokaryotes and what membranes do they have?
Aerobic prokaryotes – respiratory membrane Photosynthetic prokaryotes – thylakoid membrane
64
What are magnetosomes?
Magnetic crystals Like a compass Helps locate low-oxygen habits Common in anaerobic bacteria
65
What helps bacteria to float?
Gas vesicles
66
The gram stain procedure:
. stains gram - cells pink stains gram + cells purple
67
What can you tell me about cell wall: rigid?
Cell shape, physical protection, prevents lysis in a hypotonic environment Peptidoglycan (peptides + sugars) Some Archaeans lack cell walls, most have cell walls of proteins
68
What are the 3 basic shapes?
Spherical (cocci) Rod-shaped (bacilli) Spiral (spirillum, spirochetes)
69
What is glycocalyx?
Capsule (more dense, firmly attached) or slime layer (more loosely attached) ‘Mucilage’: hydrated polysaccharides and proteins, lipids and nucleic acids Capsule/slime layer helps bacteria evade destruction by host immune cells Mucilage: holds cells together for chemical communication: quorum sensing, DNA exchange, binding nutrients, float in water, repel attach by pathogens, glue to surfaces/form biofilms
70
What are biofilms?
Slime-enclosed communities of microorganisms Resist attack by pathogens, resist antiseptic sanitizing cleaners (take time to penetrate), glue bacteria to surfaces Function in quorum sensing
71
What is budding?
‘Bud’, break off a small daughter cell
72
What are the 3 bacterial genetic exchanges?
Conjugation Transformation Transduction
73
What is horizontal gene transfer?
DNA exchanges between different species
74
How does occur conjugation?
Via pilus or ‘mating bridge’ Cell-to-cell connect
75
Which of the following involves bacteria genetic recombination?
Conjugation
76
What is the F factor?
Genes that allow a cell to form pili and donate plasmids or chromosomal DNA F+ can form pilus F- cannot form pilus
77
What is transformation?
Bacteria-to-bacteria transfer Acquired genes from another bacteria
78
What is transduction?
Bacteriophages transfer genetic material Phages=virus Virus that infects bacteria Virus can also assist bacteria in picking up new genes
79
Which of the following results in the bacterial acquisition of new genes?
Transformation
80
What are R plasmids?
Carry antibiotic resistance genes Frequently exchanged Transform harmless bacteria into pathogens
81
What are endospores?
A thick-coated, resistant cell produced by some bacterial cells when they are exposed to harsh conditions
82
What are chemoautotrophs?
Oxidize high-energy inorganic compounds to produce energy Recycle these nutrients in the environment Help to make certain resources available
83
What are chemoheterotrophs?
Decomposers; breakdown organic compounds Carbon-based compounds Dead stuff like animals, plants, protists, bacteria, etc. Examples: most pathogenic bacteria, P. acnes, plant symbionts: fixed N
84
What are photoautotrophs?
Cyanobacteria Use sunlight to create energy Photosynthesis
85
What are photoheterotrophs?
Need light and organic molecules
86
Aerobic vs Anaerobic metabolism
Obligate aerobes: Bacteria that have-to-have oxygen (or they die) Anaerobes: May or may not tolerate oxygen Facultative anaerobes : Can do fermentation or aerobic respiration Depends on if oxygen is available

bio 122 (1 decks)

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