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BIO 215 > Exam 1 > Flashcards

Exam 1 Flashcards

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1
Q

What are the 6 Kingdoms?

A

-Bacteria
-Protista
-Archaea
-Plantae
-Fungi
-Animalia

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2
Q

Taxonomy levels LG -> SM:

A

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

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3
Q

Divergent evolution:

A

Two species evolve in different directions from a common ancestor (think darwins finches)

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4
Q

Convergent evolution:

A

two distantly-related species independently evolve similar phenotypes

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5
Q

Fossils:

A

-provide record of course of life over time
-shows waxing & waning of biological diversity

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6
Q

Homologous structures

A

structures with
different appearances and functions that all
derived from the same body part in a
common ancestor
(different functions, same underlying structure. thumb vs paw)

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7
Q

Evidence for evolution:

A

-Homologous structures
-Adaptation
-Artificial selection
-Vestigial structures

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8
Q

Vestigial structures:

A

Structures that don’t have an apparent use in the body. (think blind fish w/ eyes, fingernails on sealions, hip bones on snakes)

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9
Q

Ernst Mayr’s biological species concept:

A

groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups
(species consist of populations whose members repro w/ each other and produce fertile offspring)

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10
Q

Mechanisms of reproductive isolation:

A

-Temporal isolation
-Ecological isolation
-Geographic isolation
-Behavioral isolation
-Mechanical isolation
-Prevention of gamete fusion
-Protozygotic isolation

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11
Q

Behavioral isolation:

A

when species are reproductively isolated from others due to differences in behavior. (think red footed vs blue footed booby)

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12
Q

Mechanical isolation

A

isolation where two species cannot physically undergo fertilization.(think bumblebees & hummingbirds)

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13
Q

Postzygotic isolation:

A

Prevents normal development into reproducing adults

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14
Q

Hybridization:

A

mating between two different species with a zygote being formed

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15
Q

Hybrids often:

A

-Do not develop into adults
-Do not develop into fertile adults

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16
Q

Five elements of evolutionary change (Not in HW-equilibrium):

A

-Mutation
-Geneflow
-Nonrandom mating
-Genetic drift
-Natural selection

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17
Q

Fitness:

A

-relative to reproductive success.
-Individuals w/ one phenotype have more surviving offspring than those with an alternative phenotype.

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18
Q

Fitness is a combination of:

A

-Survival
-Mating success
-# of offspring per mating that survive
-Traits favored in one environment

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19
Q

Natural selection:

A

environmental conditions determine which individuals in a population produce the most offspring

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20
Q

3 conditions for natural selection:

A

-Variation in individuals in population
-Variation among said individuals result in the # of surviving offspring
-Variation must be genetically inherited

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21
Q

Stabilizing selection:

A

favors an average phenotype.

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22
Q

Directional selection:

A

shifts the range of preferred phenotypes

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23
Q

Disruptive selection:

A

Selects against the average phenotype and favors the extremes.

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24
Q

Gradualism:

A

slow, progressive changes over a very long time

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25
Punctuated equilibrium:
brief periods of change with long periods of stability
26
Adaptive radiation:
closely related species that have recently evolved from a common ancestor by adapting to different parts of the environment
27
Adaptive radiation occurs:
-occurs through repeated instances of sympatric speciation -produces suite of species adapted to different habitats -in an environment w/ few other species & resources (Remote islands, Hawaii/Galapagos) -Catastrophic event leading to extinction of other species
28
Hawaiian Drosophila:
The fruit fly in Hawaii that quickly evolved/adapted to the environment as it had many habitats w/ no natural prevention for fruit flies. -Diversified rapidly, both morphological and behavioral
29
Systematics of biology:
-All living organisms share many characteristics while still differing substantially from other groups -Biologists group organisms based on shared phenotypic characteristics & newer molecular sequence data -Hypothesis about evolutionary relatedness -Tremendous diversity of life
30
Phylogenic trees:
a diagram that represents evolutionary relationships among organisms.
31
Phylogenic tree ROOT:
-Beginning -indicates that an ancestral lineage gave rise to all organisms on the tree
32
Phylogenic tree BRANCH POINT:
-Beginning of branch -A branch point indicates where two lineages diverged.
33
Phylogenic tree BASAL TAXON:
-End of branch -A lineage that evolved early and remains unbranched
34
Phylogenic tree SISTER TAXA:
-When one branch point shares multiple ends -When two lineages stem from the same branch point, they are sister taxa.
35
Phylogenic tree POLYTOMY:
-When multiple 3+ branches A branch with more than two lineages is a polytomy.
36
Monophyletic/Clade:
Includes the most recent common ancestor of the group and all of its descendants (clade)
37
Paraphyletic:
Includes the most recent common ancestor of the group, but not all of the ancestor’s descendants. Usually only ones that share a certain trait
38
Polyphyletic (Extant aquatic plants):
Does not include the most recent common ancestor of all members of the group. some
39
Clade:
All the organisms within a clade stem from a single point on the tree. A clade may contain multiple groups, as in the case of animals, fungi and plants, or a single group, as in the case of flagellates
40
Scientific names:
Binomial names written in italics, genus/species, with the genus name capitalized
41
"Tree of life model"
Inspired by a sketch from Charles Darwin. the “tree of life” has a single trunk and many branches.
42
What was the first virus to be discovered?
The tobacco mosaic virus
43
Fundamental properties of life:
-Growth -Cellular division -Sensitivity -Development -Reproduction -Regulation -Homeostasis -Heredity
44
Structure of all viruses:
-Nucleic acid core surrounded by capsid -No cytoplasm, not a cell
45
Nucleic acid can be:
-DNA or RNA -Circular or linear -RNA may be segmented or not -Single/Double stranded
46
How are viruses classified?
-By genome -RNA viruses, DNA viruses, retroviruses
47
T or F: Viruses are very diverse
T -Structure, host species, and replication change wildly
48
Virions:
-are infectious virus particles outside cells -Viruses are not alive or dead but inactive or active
49
Capsid:
a protein sheath that most viruses develop around their nucleic core. (composed of repeats of ~1-3 proteins)
50
Many animal viruses have:
an envelope derived from host cell membranes w/ vital proteins
51
The 2 most common virus shapes:
– Helical (filamentous) – rodlike or threadlike – Icosahedral – 20-sided (similar to soccer ball)
52
Complex viruses:
– T-even bacteriophage – binal symmetry (head-to-tail) – Poxviruses – multilayered capsid
53
Glycoproteins:
can attach to host cell surface receptors to facilitate infection
54
T or F: Viruses can reproduce anywhere
F. Viruses can only reproduce inside cells, outside they are metabolically inert virions.
55
T or F. Virions have plenty of ribosomes and enzymes for protein synthesis
F. They lack ribosomes/enzymes required for protein or nucleic synthesis
56
Viral Genomes:
Vary greatly in both the type of nucleic acid and # of strands
57
Most RNA viruses are:
-Single stranded -Replicated in host cell's cytoplasm -Replication in cytosol is error-prone (high rates of mutation/difficult targets for immune system)
58
Baltimore classification system:
Substantial variation exists in how mRNA is produced.
59
Positive strand virus:
viral RNA serves as mRNA (Group IV: Coronaviruses)
60
Negative-strand virus:
genome is complementary to the final mRNA (Group V: influenza, rabies, ebola)
61
Retroviruses:
employ reverse transcriptase to reverse transcribe viral RNA into DNA (Group VI: HIV)
62
Most DNA viruses are:
-Double stranded -replicated in the nucleus of eukaryotic cell
63
Viruses are found:
in every kind of organisms investigated, more viruses exist than organisms.
64
Host range:
types of organisms infected, each virus has a limited host range.
65
Tissue tropism:
inside a host the virus may only infect certain tissues (e.g., rabies – nervous tissues)
66
Permissive cells:
Allow viral entry
67
T or F Viruses can remain dormant/latent for years.
T. Chicken pox can reemerge as shingles.
68
Virus reproduction cycle:
- Attachment/adsorption -Penetration/injection/entry -Synthesis/replication -Assembly -Release/egress -Eclipse period
69
Attachment/adsorption
The target is part of surface of host cell
70
Penetration/injection/entry
Pierces or fuses with cell membrane to inject viral genome
71
Synthesis/replication
-Virus may immediately take over the cell’s replication and protein synthesis enzymes to synthesize viral components
72
Assembly:
-Assembly of viral components to produce virions
73
Release/egress
-– Mature virions are released via enzymatically lysing host or budding through host cell membrane
74
Eclipse period:
- Time between attachment and the formation of new viral particles – If a cell is lysed during eclipse period, few if any active virions can be released
75
Bacteriophage:
-Viruses that infect bacteria -Diverse; united only by bacterial hosts -Called phage for short
76
Lytic cycle (virulent virus):
-Virus lyses the infected host cell
77
Lysogenic cycle (temperate virus):
-Virus doesn't immediately kill the infected cell -Virus nucleic acid is integrated into hose cell genome prophage -Integration allows viral DNA to be replicated along with the host cell’s DNA as the host divides
78
Phage conversion:
– Phenotype or characteristics of the infected (lysogenic) bacteria - altered by the prophage – Prophage genes are expressed
79
Phage conversion of Vibrio cholerae (type of bacteria):
-phage contains gene for cholera -Gene is incorporated into bacterial host genome -Cholera toxin expression converts harmless bacteria into disease- causing cholera
80
Plant viruses:
-Galls, chlorosis (yellowing), necrosis (dead tissue), abnormal growth -Can result in substantial economic losses (crops and landscaping plants)
81
Vaccinations:
-Gives immune system information – “Live” attenuated virus – causes infection but symptoms are generally very mild (e.g., smallpox) – “Killed” vaccine uses viral glycoproteins or other viral molecules (unable to infect) – mRNA vaccine provides information about surface proteins (e.g., spike protein) – Not associated with autism – Limits community spread and severity – Limits mutations -> variants (some are dangerous)
82
Antiviral drugs:
-Help limit symptoms -Generally limited success in curing
83
Human immunodeficiency virus:
- HIV/AIDS causes acquired immune deficiency syndrome -Frist reported in the US 1981 -African origin 1950's
84
Those found resistant to HIV:
– Exposed repeatedly never become positive – Others become HIV-positive without developing AIDS – Others have little resistance and progress rapidly from infection to death – Resistance may be related to smallpox resistance (lack surface receptor)
85
HIV targets:
CD4+ cells, mainly helper T-cells
86
Helper/T-cells
– Without these cells, the body cannot mount an effective immune response – Host may ultimately die from opportunistic infections (otherwise rare conditions) – Clinical symptoms usually appear after 8–10 year latent period
87
HIV infection cycle:
1. Attachment 2. Entry 3. RNA -> DNA 4. DNA -> host genome 5. Transcription -> viral genome and viral proteins 6/7. HIV assembly and export
88
Influenza:
-One of the most lethal viruses in human history – 20–50 million people died worldwide between 1918 and 1919.
89
Flu viruses are enveloped in _____ viruses
Animal
90
3 types based on capsid protein
-Type A serious epidemics in humans and other animals -Type B/C mild human infections
91
Subtypes:
– Hemagglutinin (H) – Aids in viral entry – Neuraminidase (N) – Aids in viral exit
92
Flu viruses can also undergo:
-Genetic recombination when 2 subtypes infect the same cell -creates novel combinations of spikes unrecognizable by human antibodies
93
Antigenic shifts have caused the following pandemics:
– Spanish flu of 1918, A(H1N1) * Killed 20–50 million worldwide – Asian flu of 1957, A(H2N2) * Killed over 100,000 Americans – Hong Kong flu of 1968, A(H3N2) * Infected 50 million in U.S. * Killed 70,000 in U.S.
94
Emerging viruses:
-Are viruses that extend their host range -Often deadly to new host
95
Hantavirus:
-Causes deadly pneumonia -Natural host is deer mice -Controlling deer mice has limited disease
96
Ebola virus:
– Causes severe hemorrhagic fever – Among most lethal infectious diseases (70-90% mortality) – Host – great apes and bats
97
SARS-CoV-2:
– Severe acute respiratory syndrome – Also affects other systems – Drug treatments are being developed and tested – Long-term efficacy of vaccines is being evaluated
98
Virus & Cancer relationship:
-Viruses may contribute ~15% of all human cancers -They cause cancer by altering the growth properties of human cells
99
Prions
"Proteinaceous infections particles" -Causes transmissible spongiform encephalopathies. (Mad cow) -Host has normal prion proteins, misfolded ones cause disease
100
Viroids:
-Tiny naked molecules of circular RNA (no protein) -Causes diseases in plants

BIO 215 (1 decks)

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