Bio 104 Flashcards
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2
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3
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4
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5
Q
What are the three groups based on the mode of nutrition in fungi?
A
- Saprophytic
- Parasitic
- Symbiotic
Saprophytic fungi feed on dead organic substances, parasitic fungi live on other organisms, and symbiotic fungi have mutually beneficial relationships with other species.
6
Q
What is the definition of saprophytic fungi?
A
Fungi that obtain their nutrition by feeding on dead organic substances.
Examples include Rhizopus, Penicillium, and Aspergillus.
7
Q
What is the definition of parasitic fungi?
A
Fungi that obtain their nutrition by living on other living organisms.
Examples include Taphrina and Puccinia.
8
Q
What is the definition of symbiotic fungi?
A
Fungi that live in an interdependent relationship with other species, benefiting both.
Examples include lichens and mycorrhiza.
9
Q
What are the classifications of fungi based on spore formation?
A
- Zygomycetes
- Ascomycetes
- Basidiomycetes
- Deuteromycetes
Each group has distinct characteristics regarding spore formation.
10
Q
What is the primary type of spores produced by Zygomycetes?
A
Zygospores (sexual) and sporangiospores (asexual).
Zygomycetes are characterized by the fusion of two different cells.
11
Q
What are Ascomycetes commonly known as?
A
Sac fungi.
They produce ascospores and reproduce asexually by conidiospores.
12
Q
What type of reproduction is primarily associated with Basidiomycetes?
A
Sexual reproduction occurs by basidiospores.
Common examples include mushrooms.
13
Q
What defines Deuteromycetes?
A
They do not reproduce sexually and are called imperfect fungi.
Asexual reproduction occurs by conidia.
14
Q
What is the term for the sexual mode of reproduction in fungi?
A
Teleomorph.
15
Q
What is the term for the asexual mode of reproduction in fungi?
A
Anamorph.
16
Q
What is the primary structural component of the fungal cell wall?
A
Chitin and polysaccharides.
17
Q
What is mycelium?
A
A mesh-like structure formed by hyphae in fungi.
18
Q
What are the characteristics used to describe colony morphology of fungi?
A
- Form
- Size
- Elevation
- Margin/border
- Surface
- Opacity
- Colour
These characteristics help identify different fungal colonies.
19
Q
What are the four major shapes of bacteria?
A
- Bacillus (rod shape)
- Coccus (spherical shape)
- Spirilla (spiral shape)
- Vibrio (curved shape)
Each shape can further be classified based on their arrangements.
20
Q
What type of bacteria are staphylococci?
A
Cocci arranged in clusters.
21
Q
What is the Gram staining technique used for?
A
To classify bacteria as Gram-positive or Gram-negative based on their cell wall structure.
22
Q
What color do Gram-positive bacteria appear after staining?
A
Purple.
23
Q
What color do Gram-negative bacteria appear after staining?
A
Pink.
24
Q
What is a bacteriophage?
A
A virus that infects bacteria.
25
What is the host range of a virus?
The specific species of organisms a virus can infect.
26
What are obligate intracellular parasites?
Organisms that can only reproduce inside a living cell.
27
What is the composition of a virus's genome?
Either DNA or RNA, never both.
28
What is the definition of zoonoses?
Diseases that can be transmitted from animals to humans.
29
What is the size range of a virion?
From 20 nm to 900 nm.
30
What is the role of crystal violet in Gram staining?
It is the primary stain that colors the specimen purple.
31
What does the decolorizer do in the Gram staining procedure?
It determines whether the cell will retain the primary stain.
32
What is the function of safranin in Gram staining?
It serves as the counter stain, coloring Gram-negative bacteria pink.
33
What are reverse zoonoses?
Infection of an animal by a virus that originated in a human.
34
What is a virion?
A viral particle that is small and cannot be observed using a regular light microscope.
35
What is the size range of a virion?
20 nm for small viruses up to 900 nm for typical, large viruses.
36
What are giant viral species examples?
* Pandoravirus salinus
* Pithovirus sibericum
37
What are the two main components of viruses?
Nucleic acid (RNA or DNA) and a protein coat called a capsid.
38
What is a capsid?
A protein coat surrounding the nucleic acid of a virus.
39
What are capsomeres?
Protein subunits that make up the capsid.
40
What distinguishes naked viruses from enveloped viruses?
Naked viruses consist of only a nucleic acid and capsid; enveloped viruses have a lipid layer surrounding the capsid.
41
What is the origin of the viral envelope?
A small portion of phospholipid membrane obtained as the virion buds from a host cell.
42
What are spikes in the context of viruses?
Protein structures extending from the capsid that allow the virus to attach and enter a cell.
43
What are the three shapes of capsids?
* Helical
* Polyhedral
* Complex
44
What is an example of a naked helical virus?
Tobacco mosaic virus (TMV).
45
What is an example of an enveloped helical virus?
Ebola virus.
46
What is an icosahedral capsid?
A three-dimensional, 20-sided structure with 12 vertices.
47
What is a complex viral shape?
A shape that exhibits features of both polyhedral and helical viruses.
48
What is the role of the sheath in a bacteriophage?
It connects the polyhedral head to the tail fibers and tail pins.
49
What organization maintains a universal virus taxonomy?
International Committee on Taxonomy of Viruses (ICTV).
50
How many orders, families, and genera of viruses has the ICTV classified?
Seven orders, 96 families, and 350 genera.
51
What is the suffix for viral family names?
-viridae
52
What is the suffix for viral genus names?
-virus
53
What does the Baltimore classification system use for classification?
Genomes (DNA or RNA, single versus double stranded, and mode of replication).
54
What are some informal categories viruses are grouped into?
* Naked or enveloped structure
* Single-stranded or double-stranded DNA or RNA
* Segmented or nonsegmented genomes
* Positive-strand or negative-strand RNA
55
What type of virus is human immunodeficiency virus (HIV)?
+ ssRNA enveloped virus.
56
What are some clinical features of herpes viruses?
* Skin lesions
* Cold sores
* Genital herpes
* Sexually transmitted disease
57
What virus family is associated with gastroenteritis and severe diarrhea?
Reoviridae.
58
What type of virus is adenovirus associated with?
Respiratory tract infection.
59
What are the characteristics of the Rhabdoviridae family?
− ssRNA, enveloped, causing rabies.
60
What are the three groups based on the mode of nutrition in fungi?
* Saprophytic
* Parasitic
* Symbiotic
## Footnote
Saprophytic fungi feed on dead organic substances, parasitic fungi live on living organisms, and symbiotic fungi have interdependent relationships with other species.
61
What is the term for fungi that obtain their nutrition by feeding on dead organic substances?
Saprophytic
## Footnote
Examples include Rhizopus, Penicillium, and Aspergillus.
62
What type of fungi obtain their nutrition by living on other living organisms?
Parasitic
## Footnote
Examples include Taphrina and Puccinia.
63
What is the symbiotic association between algae and fungi called?
Lichens
## Footnote
In lichens, fungi provide shelter for algae, and algae synthesize carbohydrates for fungi.
64
What are the two types of spores formed by Zygomycetes?
* Zygospores (sexual)
* Sporangiospores (asexual)
## Footnote
Zygomycetes are characterized by the fusion of two different cells.
65
What are the sexual spores produced by Ascomycetes called?
Ascospores
## Footnote
Asexual reproduction in Ascomycetes occurs by conidiospores.
66
What is the unique characteristic of Deuteromycetes?
They do not reproduce sexually.
## Footnote
Asexual reproduction occurs by conidia.
67
What are the two modes of reproduction in fungi?
* Sexual
* Asexual
## Footnote
Sexual reproduction is referred to as teleomorph, while asexual reproduction is referred to as anamorph.
68
What structure do fungi possess that is made up of chitin and polysaccharides?
Cell wall
## Footnote
The cell wall is essential for the structural integrity of fungi.
69
What is the mesh-like structure formed by hyphae in fungi called?
Mycelium
## Footnote
Mycelium is formed from long thread-like structures known as hyphae.
70
What is colony morphology?
A method to describe the characteristics of an individual colony of fungi
## Footnote
It helps in identifying different types of fungi based on colony appearance.
71
What are the four major shapes of bacteria?
* Bacillus (rod shape)
* Coccus (spherical shape)
* Spirilla (spiral shape)
* Vibrio (curved shape)
## Footnote
Each shape has specific arrangements, such as staphylococci and streptococci.
72
What is the primary stain used in the Gram staining procedure?
Crystal Violet
## Footnote
Crystal violet stains both Gram-positive and Gram-negative bacteria purple.
73
What is the difference in the cell wall structure of Gram-positive and Gram-negative bacteria?
* Gram-positive: Thick peptidoglycan layer
* Gram-negative: Thin peptidoglycan layer with an outer membrane
## Footnote
The outer membrane of Gram-negative bacteria protects against certain antibiotics.
74
What are the two types of transmission for viral pathogens by arthropods?
* Mechanical transmission
* Biological transmission
## Footnote
Mechanical transmission occurs through physical contact, while biological transmission occurs through biting.
75
What is the term for the range of organisms that a virus can infect?
Host range
## Footnote
Viruses typically infect specific hosts and cell types within those hosts.
76
What are bacteriophages?
Viruses that infect bacteria
## Footnote
Bacteriophages are specific to bacterial cells and can cause cell lysis.
77
What is the genome structure of viruses?
DNA or RNA genome (never both)
## Footnote
The genome is surrounded by a protein capsid.
78
What is the role of safranin in the Gram staining procedure?
Counter stain that gives a pink or reddish color to Gram-negative bacteria
## Footnote
Safranin does not affect already stained Gram-positive bacteria.
79
What is the characteristic of fungi regarding chlorophyll?
Fungi lack chlorophyll
## Footnote
This means fungi cannot perform photosynthesis.
80
What is the intermediate stage in some fungi where two haploid hyphae fuse but do not form a diploid cell?
Dikaryophase
## Footnote
This stage is followed by the formation of diploid cells.
81
What do fungi store their food in?
Starch
## Footnote
This is a key characteristic of fungi.
82
What is the Gram staining technique used for?
To classify bacteria into Gram-positive or Gram-negative
## Footnote
It is a crucial step in bacterial identification.
83
What is the result of a Gram-positive bacterium after the staining procedure?
Purple color
## Footnote
This indicates the bacterium retains the primary dye.
84
What is the result of a Gram-negative bacterium after the staining procedure?
Pink or red color
## Footnote
This indicates the bacterium has been decolorized and taken up the counter stain.
85
What are reverse zoonoses?
Infection of an animal by a virus that originated in a human
86
What size range do virions typically fall within?
20 nm to 900 nm
87
What are giant viral species examples?
* Pandoravirus salinus
* Pithovirus sibericum
88
What is a capsid?
A protein coat surrounding the nucleic acid of a virus
89
What are capsomeres?
Protein subunits that make up a capsid
90
What are the two categories of viruses based on composition?
* Naked (nonenveloped) viruses
* Enveloped viruses
91
What is the origin of the viral envelope?
It is obtained as the virion buds from a host cell
92
What are spikes in viral structures?
Protein structures that allow the virus to attach and enter a cell
93
What are the three shapes of viral capsids?
* Helical
* Polyhedral
* Complex
94
What shape does a helical capsid take?
Cylindrical or rod shaped
95
What is an icosahedral capsid?
A three-dimensional, 20-sided structure with 12 vertices
96
What is a complex viral shape?
A shape that has features of both polyhedral and helical viruses
97
What classification system does the ICTV use for viruses?
A system based on viral genetics, chemistry, morphology, and mechanism of multiplication
98
What is the format for naming viral families and genera?
Family names end in -viridae and genus names end in -virus
99
How many orders, families, and genera have been classified by the ICTV?
* 7 orders
* 96 families
* 350 genera
100
What is the Baltimore classification system based on?
Genomes (DNA or RNA, single versus double stranded, and mode of replication)
101
What types of genomes can viruses have?
* dsDNA
* ssDNA
* dsRNA
* ssRNA
102
What is an example of a dsDNA enveloped virus?
Herpesviridae
103
What clinical feature is associated with Parapoxvirus?
Skin lesions
104
What is the clinical feature of Rotavirus?
Gastroenteritis
105
Fill in the blank: Viruses formed from only a nucleic acid and capsid are called _______.
naked viruses
106
True or False: All viruses contain both RNA and DNA.
False
