bio test: oct 11 Flashcards
(97 cards)
1
Q
geologic record
A
2.1 BYA (prokaryotes- stromatolites were 3.8)
2
Q
Eukaryotes are what type of group?
A
Monophyletic. (common ancestor gave rise to all)
3
Q
Eukaryote last common ancestor had:
A
- cells w nuclei, nuclear envelope with pores
- mitochondria
- cytoskeleton (of microtubules/microfilaments)
- flagella or cilia - for motility
- chromosomes organized by histones
- undergo mitosis
- capable of sexual reproduction
- cell walls - lost in many groups
4
Q
Aerobic respiration/aerobic metabolism
A
Seen in all lineages of eukaryotes (because of mitochondria). Aerobic metabolism produces lots of ATP (ATP is the basis of all energy).
5
Q
Endosymbiosis theory
A
Eukaryotes result from one cell engulfing another, one lived in the other, and they co-evolved.
- unclear whether this was before or after nucleus
6
Q
Our energy-harvesting is very similar to
A
bacteria
7
Q
Our nuclear genes and molecular machinery is very similar to
A
archaea
8
Q
mitochondria are present only in
A
eukaryotes (1-1000+ per cell)
9
Q
mitochondria are shaped like
A
proteobacteria with two membranes
10
Q
to look at organisms relationships we look at what type of DNA?
A
mitochondrial
11
Q
just looking at differences between individuals
A
nuclear DNA
12
Q
have their own genome!
A
- circular chromosome
- special ribosomes (similar to prokaryotes)
- some genes in the nucleus are transferred from the mitochondria (mimicking prokaryote -> nucleus)
13
Q
Mitochondria divide…
A
Independently - like binary fission
14
Q
There are anaerobic eukaryotes?
A
True. Assumed to be an evolutionary reversal (ex. anaerobic eukaryote lost ability of aerobic respiration)
15
Q
plastids are like mitochondria BUT…
A
They are photosynthetic (bc of their chloroplasts), (similar bc circular chromosomes)
16
Q
Plastids origin
A
symbiotic origin
- derived from cyanobacteria (happened twice, primary endosymbiosis)
17
Q
Primary vs Secondary endosymbiosis
A
first: archaeplastida (most plants today)
second: only a few species
+ Major groups of algae (major protozoans), they have secondary plastids surrounded by 3 membranes
18
Q
protists are a eukaryote?
A
true
19
Q
what type of group is protists
A
Paraphyletic.
- over 100 000 species
- very diverse in structure and function
- defined as a eukaryote that is not an animal, plant or fungi
20
Q
Cell structure of protists
A
- complex
- micrometres to more than metres
- animal OR plant like
- can have pellicles: interlocking protein strips
21
Q
Protist metabolism
A
Highly varied:
- aerobic or anaerobic
- photoautotrophs
- heterotrophs
22
Q
Examples of heterotroph protists
A
phagocytosis:engulfing cells
Saprobes: eat dead things
Mixotrophs: eat a bit of everything
23
Q
Protist Motility
A
- flagella, cilia, or pseudopodia
- some can not move at all
- some move lots
Taxis: refers to movement - have amoeboid movement*
24
Q
Lifecycles of Protist
A
- can undergo asexual reproduction- binary fission
- sexual reproduction- meiosis and fertilization
- many switch from sexual to asexual
25
Habitats of protists
highly varied - most have some water connection
26
amoeba movement
pseudopods (blob like)
27
archaeplastids
- red and green plants*
- descendants are heterotrophic protists and cyanobacterium
28
alternation of generations
there are two different generations within the lifecycle - sporophyte (diploid stage) and gametophyte (haploid stage)
29
glaucophytes
chloroplasts retain cell wall of cyanobacteria
30
Green Algae
most abundant! Subgroups:
1) charophytes- closest living relatives to land plants
2) Chlorophytes- from fresh water and damp soil ex. volvox
31
Amoebazoa
- contain the gymnomoebae
- slime molds!
32
slime molds
similar to fungi, types:
plasmodial: large multinucleate cells- netlike feeding structure, ex "dog vomit"
cellular: interdependent cells in good conditions, aggregate in poor conditions
33
Opisthokonto
- single posterior flagellum
- chanoflagellates*
34
chloroplasts are derived from?
secondary endosymbiosis
- this is seen in Rhizeria group
35
Rhizerians
- "tests" / shells are crucial to the carbon cycle
1) foraminiferans- heterotrophic, porous tests
2) radiolarians- glassy silica shell
3) cercozoa- naked and shelled (or not!)
36
Chromalveolata
engulfed photosynthetic red algae
37
Within Chromalveolata: Alveolata
1) Dinoflagellates: photosynthetic, heterotrophic, mixotrophic, bioluminescent, red tides (eruption of dinoflagellates)
2) Apicomplexans: parasitic- malaria (plasmodium!)
3) Ciliates: paramecium
38
Within Chromalveolata: Straminopiles
1) diatoms: unicellular photosynthetic- SiO2
2) Brown Algae: marine multicellular- giant kelp
3) oomycetes- "egg type fungus", parasitic or saprobes
39
Excavata
- many cause disease, can be photosynthetic/heterotrophs
- tend to be asymmetrical, feeding groove down middle
40
Groups of Excavata
1) Diplomonads: anaerobic, 2 haploid nuclei- giardia
2) Parabasalids: STD, others inhabit rumen or termite gut
3) Euglenozoans: parasites, heterotrophs, autotrophs, mixotrophs ex: euglena- mixotroph (green and can photosynthesize, feeds on lots)
41
Flagel
Can kill flagellates (Giardia) causing diarrhea in hikers
42
Trypanosoma
causes African sleeping syndrome, infectious and multiplies: goes into humans through fly bite.
43
Protists as Producers
1) Phyto and zooplankton (25% photosynthesis, base of marine food chain)
2) Symbionts- Corals (Anthozoans and dinoflagellates)
44
Pathogenic Protists
1) Human and animal parasites (Plasmodium-malaria, trypanosome-sleeping sickness and Chagas disease, Giardia spp, trichomonas, lieshmania)
2) Plant parasites (oomycetes- grapes and potatoes)
45
mycology
the study of fungi
46
fungal cells- eukaryote
- dna bound nucleus
- fungal cell walls (pigments- uv radiation, toxic & thick bc chitin an glucose)
- plasma membrane like animals (but cholesterol replaced w ergosterol)
47
Fungal Growth: Vegetative Body
Can be Unicellular or Multicellular
1) Unicellular = yeasts, Candida sp.
2) Multicellular=hyphae
48
Fungal growth: cycle includes...
Both vegetative and reproductive stages
1) vegetative = mycelium (tangle of hyphae), can grow very large on many media
2) reproductive= "mushroom"
49
Fungal Growth: Hyphae
divided into singular cells with septa
50
Fungal Nutrition: Obligate aerobes
require O2
51
Fungal Nutrition: obligate anaerobes
absence of O2 (O2 is toxic for them)
52
Fungal Nutrition: Facultative anaerobes
Best in O2 but can survive without
53
Fungal Nutrition: Heterotrophs, Saprobes, Parasites
- acquire energy from dead or decaying matter
- external digestion
- many are parasitic
- some predators (nematophagous fungi)
54
Fungal Nutrition: digestion
external digestion
- the reverse of our ingestion and digestion
- digest w enzymes then absorb
- can digest cellulose and linen*
- potential bioremediations
55
Predator Fungal EX: Haustoria
specialized hyphae- inject enzymes
56
Fungal reproduction
Sexual and asexual
- perfect fungi - both
- imperfect fungi - asexually - mitosis
57
Asexual Fungal Reproduction
- fragmentation, budding, spores (asexually through mitosis)
- sporangium- reproductive sac
- conidiophores - uni/multicellular - released from hypha
58
Sexual Fungal Reproduction
- often response to adverse environmental conditions
- two mating types produced
1: homothallic- same mycelium,
2: heterothallic- requires 2 different (but compatible) mycelium
59
3 stages of sexual reproduction
1) Plasmogamy: (cytoplasm unite)- dikaryotic cell (2 haploid nuclei)
2) Karyogamy: (nuclei unite) - diploid zygote nucleus
3) Meiosis: spores released into the environment
60
5 phyla of fungi
1- chytridiomycota
2- zygomycota
3- ascomycota
4- basidiomycota
5- glomeromycota
61
Chytridiomycota
only class= Chytridiomycetes
- simplest and most primitive (500 MYA)
- most unicellular, some multicellular
- only fungi with flagella
- most aquatic
- parasitic species- plants, insects, amphibians
62
Zygomycota: Conjugated Fungi
- most are saprobes (black bread mold)
- used in industry (steroid hormones)
- usually asexually reproduce- sporangia
- sexual reproduction- conjugation (need two opposing mating strands), zygospores (diploid) - meiosis - spores
63
Ascomycota - Sac Fungi
Ascus= saclike structure contains haploid ascospores
Economic importance- food, yeasts, parasites
Reproduction: Asexual- conidiophores produce conidiophores
Sexual- 1) male strain- antheridium
2) female strain- ascogonium
3) asci fill ascocarp (fruiting body)
64
Basiodimycota - Club Fungi
Basidia: club-like fruiting bodies
- common mushrooms, shelf fungi, smuts and rusts
- mostly edible mushrooms, also many deadly ones
65
Reproduction in Basidiomycota
alternation of generations
- haploid and eukaryotic - sexual spores more common
- male and female strains fuse
- diploid zygote- meiosis
- basidiospores in basidiocarp (mushroom)
66
Imperfect fungi
- asexually reproducing Ascomycota and Basidiomycota
- form visible "fuzzy" mycelia = mold
- commercial importance (ripening cheese "blue cheese", penicillium)
- Aflatoxins- toxic compounds
67
Glomeromycota
*Arbuscular mycorrhizae- plant roots
- cannot survive without plant roots
68
ecological roles: Fungi
- universal decomposers (major roles in cycling N2 and P)
- live in most habitats
- more common forest floor (dark and moist)
- need moisture to thrive and move nutrients
69
Symbiosis and Mutualism in Fungi
Symbiosis- living together
Mutualism- both benefit
- 90% vascular plants
70
lifecycle
- the majority is diploid, going from diploid to haploid = meiosis, mitosis is just one division (haploid to haploid or diploid to diploid, not one to another)
71
how do fungi feed
extracellular digestion
72
mycorrhizal fungi
(myco=fungus, rhizo = root)
- fungi mutualism with plant roots, give plants nitrogen and phosphorous, plant gives fungi sugar
Ectomychorrizal: envelope roots in sheath (zygomycota, accomycota, basidiomycota)
Endomychorrizal (arbuscular) fungi: inside the root of Glomeromycota
73
Lichens: mutualism
- ascomycota or basidiomycota
- alga or cyanobacteria
*Alga and Fungi: alga provides C, fungi provides protection and attachment to substrate
Reproduction- spreading via Soredie (mycelia sourrounded algal cells
- environmental indicators!
74
Fungal/Animal mutualism: insect/fungal
- scale insects and Basidiomycota
- fungi farming ants
75
Fungal/Animal mutualism: Fungivores
- disperse fungal spores in feces
- black truffles
76
Review relationship terms!
Mutualism: both benefit
Commensalism: one benefits, one unaffected
Parasitism: one benefits, one harmed
77
Fungal Plant Parasites and Pathogens: Direct harm in...
Rotting crops and food-producing plants.
- decay or stored crops
- smuts and rusts
78
Fungal Plant Parasites and Pathogens: Secondary effects of fungal infection
- ergot
- aflatoxin
79
Mycosis
disease resulting from fungus
80
Mycotoxins
poisoning of humans and animals by food contaminated by fungal toxins
81
fungal infections difficult to treat
ones in eukaryotes, because antibiotics only work on prokaryotes
82
Other animal and human parasites
- mould sensitivity/toxic mould
- chytrid fungi and amphibians
- human infections- skin or respiratory
83
beneficial use of fungi
1) food
2) medicine
3) biological control
84
mycelium of fungi
haploid
- they come together to form diploid
85
fungal stage where cells unite but nuclei are not yet fused
plasmogamy
86
most ancestral fungal group that has swimming gametes
chytridiomycota
- ex. white fungus on frogs
87
gills on portabello mushroom
basidiomycota
88
black bread mold
zygomycota
89
fungi are universal --- ecologically
decomposers
90
mycelium touch
the ground
- adjust nutrients by extracellular digestion before pulling in
91
air we breathe is what % Nitrogen
78%
92
T/F: Nitrogen in the air can be used by most organisms
False
93
Some of earliest eukaryotes 3.8 BYA
Stromatolites
94
energy producing organelle only in eukaryotes
mitochondria
95
plant chloroplasts are similar to...
our mitochondria in evolutionary origins
- endosymbiosis
96
protists are monophyletic or paraphyletic
paraphyletic
97
slime molds are an example of what group
amoebozoa
