Midterm 3 (#14, 15, 16) Flashcards
1
Q
describe the phylogenetic tree of fungi
A
they are eukaryotes, closely related to animals, not plants
2
Q
what is the fungi mode of nutrition?
A
types of heterotroph –> decomposer and symbionts
3
Q
what type of relationships do fungi usually have with other animals
A
frequently mutualistic symbiosis
4
Q
how many species of fungi have been described and named?
A
110,000 species of fungi… hundreds more are discovered each year
5
Q
how many species of fungi can be found world wide
A
6 million
6
Q
why are fungi important 3 main reasons
A
1) fungal mutualisms are very important for plants –> obtain nutrients and protect plants from herbivores
2) animals participate in fungal mutualism
3) nutrient cycling (carbon cycle)
7
Q
why do people care about fungi?
A
disease, essential for crop growth and crop spoilage, food source, antibiotics, bread, beer, cheese, industrial enzymes
8
Q
fungi are more closely related to _______ than
A
animals than to land plants
9
Q
which is more difficult to treat in humans fungal or bacterial infections
A
fungal infections
10
Q
why are fungal infections harder to treat than bacterial infection?
A
drugs that interrupt fungal physiology are likely to damage humans
11
Q
what key traits link animals and fungi (4)
A
1) DNA SEQUENCE DATA
2) both animals and fungi synthesize chitin
3) flagella in chytrid spores and gametes are similar to animal flagella
4) animal and fungi store glucose as the polysaccharide glycogen
12
Q
microsporidians?
A
are fungi that are single-celled, parasitic eukaryotes
13
Q
do microspores have a distantly related sister group to fungi?
A
NO
14
Q
what is the hypothesis regarding microspores
A
fungicides (substances that can kill fungi or slow their growth) can cure microsporidian infections in bee colonies, silkworm colonies, and AIDS patients
15
Q
chytrids and zygomycetes are …
A
POORLY resolved
16
Q
Chytrids and zygomycetes have what on the phylogenetic tree?
A
polytomy on phylogenetic tree
17
Q
swimming gametes and zygosporangium evolved….
A
more than once or both were present in a common ancestor but lost in certain lineages
18
Q
glomeromycota is …
A
monophyletic
19
Q
adaptations that helped glomeromycota to live with plant roots as mycorrihzae evolved how many times?
A
ONCE
20
Q
Basidiomycetes are ….
A
monophyletic
21
Q
how many times did the basidium evolve?
A
once
22
Q
ascomyctes are …
A
monophyletic
23
Q
how many times did the ascus evolve?
A
ONCE
24
Q
basidiomycota and Ascomycota form what?
A
a monophyletic group
25
Basidiomycota and Ascomycota both form. WHAT and how many times did it evolve
septate hyphae (cellular compartments made by septa) and large “fruiting” structures; this growth habit
evolved once
26
sister group to fungi comprises what?
animals plus choanoflagellates
27
The earliest fungi were___, and the switch to teresterial life occurred ______________
aquatic, and evolved early in evolution of fungi
28
fungi have very ____ _____
simple bodies
29
what are the two growth forms of fungi and how do they exist
1) single celled forms - YEAST
2) multicellular, filamentous form - mycelia
30
mycelia are made of
branching networks of very thin hyphae
31
TRUE OR FALSE: some species of fungi can adopt both forms of growth
TRUE
32
bc of the thin branching networks of mycelia
1) fungi have the highest surface-area-to-volume ratio of all multicellular
organisms
2) Nutrient absorption is extremely efficient
3) Prone to drying out:
33
since mycelia are prone to drying out what are the results
* Thus most abundant in moist environments
* Reproductive spores are resistant to drying out
* Spores can endure dry periods and then germinate
34
ALL mycelia are ______
DYNAMIC
35
describe the growth and life cycle of mycelia, and the one word that describes it all
They constantly grow in the direction of food sources and die back in areas
where food is running out --> DYNAMIC
36
The body shape of a fungus ......
can change almost continuously throughout its life
37
Both the reproductive structure and mycelium .....
are composed of hyphae.
38
*Mycelia are what to a fungi?
an adaptation that supports external digestion and the absorptive
lifestyle of fungi
39
Many species of fungi .....
do not reproduce sexually
40
In fungi that don't reproduce sexually, the lineages have important
morphological differences
41
Most hyphae are divided into compartments by
septa
42
The Nature of Hyphae Hyphae are
the long, narrow filaments of mycelium.
43
the pores in the mycelium filaments allow for
materials to flow between the compartments created by the septa
44
Coenocytic hyphae consist
of multinucleate cells.
45
what does coenocytic mean
they lack septa
46
some fungi can lack septa which means they are...
COENOCYTIC
47
in the mycelium descibe the nuclei
– Many nuclei are scattered throughout the mycelium
48
in fungi how can nutrients movemore rapidly
through septa pores or through coenocytic fungi from uptake to growth areas
49
MEMORISE THE GENERALIZED FUNGAL LIFE CYCLE
pg 16 of lecture 14
50
what are the key stages of the chytrid life cycle
1. Haploid adults form gametangia:
– Mitosis produces male and female swimming gametes
2. Gametes fuse to form a diploid zygote
3. The zygote grows into a diploid sporophyte
4. Haploid spores, which disperse by swimming, are produced by meiosis inside
the sporophyte’s sporangium
***no heterokaryotic stage
51
Zygomyctes life cylce
***** Plasmogamy forms a spore-forming zygosporangium (unique to this fungi) that develops a tough, resistant coat
* Inside the zygosporangium, nuclei from the mating partners fuse—meaning that karyogamy
occurs
* Mycelia can also reproduce asexually by making sporangia, which produce haploid spores by
mitosis:
* The spores are then dispersed by the wind
52
Key features of basidiomycota?
club-shaped cells; karyogamy occurs before plasmogamy
53
Zygosporangia are
Distinctive spore-producing structures of zygomycetes
54
Key features of ascomycota?
sac-like cells called ascus; they have sex
55
What is an ascus?
sac-like cells, part of ascomycota
56
how are Zygosporangia formed
Formed from fusion of cells from joined-together haploid hyphae from two individuals
57
mushrooms are sexual reproductive structure produced by
basidiomycetes
58
All basidiomycete reproductive structures originate
from the dikaryotic hyphae of mated
individuals:
59
karyogamy occurs within the
basidia
60
The club-like, spore-producing cells are
basidia
61
where do basidia form
form at the ends of dikaryotic hyphae
62
Each basidium produces
four spores
63
Hyphae or specialized structures from different mating types fuse to form
a heterokaryotic cell with many nuclei
64
Each ascus produces
eight spores
65
ALL fungi absorb
food from their surroundings
66
what drive the diversification of fungi
Evolution of novel methods for absorbing nutrients from
a wide array of food sources
67
The first plants in the fossil record are closely associated
with fungal fossils
68
The ability to absorb nutrients from fungi may have been crucial
in the early
evolution of land plants
69
Fungi and land plants often have a
symbiotic relationship
70
Mutualistic relationships
benefit both species
71
parasitic relationships
one species benefits at the expense of the other
72
Commensal relationships
benefit one species while the other is unaffected
73
Mycorrhizal fungi is an example of
plant symbioses via roots
74
whta two types of fungi are present in the mycorrhizal fungi symbiosis with plants via roots
Ectomycorrhizal fungi
Arbuscular mycorrhizal
75
Arbuscular mycorrhizal fungi (AMF)
contact plasma membranes of root cells.
76
Ectomycorrhizal fungi (EMF)
form sheaths around roots and penetrate between root cells.
77
EMF are found where
on many tree species in temperate regions
78
EMF hyphae penetrate
decaying material and release peptidases:
Peptidases cleave proteins, releasing amino acids that the hyphaetransport to spaces between the plant root cells:
▪ The plant can now absorb the amino acids
79
EMF also provide ______ ions to the host plant, in return, the EMF receive _____
phosphate, sugar
80
* Endophytes
(“inside-plants”)—organisms that live
between and within plant cells
81
ENdophytes live in close association with
ROOTS OR ABOVEGROUND TISSUE OF PLANTS
82
WHAT was Unknown before the 1940s but extremely common and
highly diverse
Endophytes
83
what can some endophytes do
– Some increase drought tolerance of their host plants
– Some produce compounds that benefit plants by
deterring or killing herbivores
– Receive benefits by absorbing sugars from plants
84
what three adatations make fungi such effective decomposers
- Given enough time, fungi can turn even the hardest, most massive trees into soft soils
* The large surface area of a mycelium makes nutrient absorption exceptionally efficient
* Saprophytic fungi can grow toward the dead tissues that supply their food
85
fungi speed up what and how?
the carbon cycle since they break down dead trees in terrestrial ecosystems
86
what are saprophtyes
fungi that digest dead plant material
87
how do saprophytes help the carbon system
through terrestrial systems
88
what are the two basic components of the carbon cycle
fixation of carbon by land plants
release of co2 from cellular respiration
89
what is hard for most organisms to use
lignin and cellulose
90
without fungi, a lot of ....
carbon would be locked away in dead plant matter
91
how do saprophytic fungi degrade lignin
they use lignin peroxidase to break down lignin and expose cellulose that can fuel growth and reproduction
92
fungi cant live on ___ alone
lignin
93
how do fungi degrade cellulose
fungi secrete cellulases into the extracellular environment--> cellulase convert cellulose into glucose that the fungus can absorb and use as a source of food
94
How many species have been described to date
1.4 million species
95
Where did animals originate from
single-celled eukaryotes
96
what lineage did animals come from
lineage called Opisthokonta
97
What does the Opisthokonta include?
fungi, choanoflagellates, animals
98
what are the closest living relatives to animals and when did they share a common ancestor
Choanoflagellates are closets living relatives to animals ; share common ancestor 900 million years ago
99
WHAT TYPE of clade are animals
MONOPHYLETIC CLAD
100
what are key traits of the monophyletic clade of animals (4)
1) multicellular eukaryotes, with no cell walls but with an extensive extracellular matrix
2) Heterotrophs
3) move under own power at some point in life cycle
4) all animals other than sponges has NEURONS, and MUSCLE cells that change shape of body by contraction
--> therefore neurons and muscles are not synapomorphies
101
ALL animals have a common ancestor that was a
MULTICELLULAR organism
102
single orgin of animals is based on data from
fossils
comparative morphology
comparative development
comparative genomics
103
prevailing hypothesis about ancient linage of animals
prevailing hypothesis is that sponges are most ancient linage of animals
104
what type of clade are sponges
PARAPHYLETIC group - containing some, but not all descendants of common ancestor
105
What genetic tools do sponges have that are needed for multicellularity
cell cell adhesion
cell- ecm adhesion
few even have epithelium
106
Do sponges have complex tissue? If not, what do they have
NO, groups of similar cells that are organized into tightly integrated structural and functional units
107
what is Epithelium
layer of tightly joined cells that covers interior and exterior surface of an animal
108
_______ is essential to animals form and function
Epithelium
109
What type of organism has TRUE Epithelium
sponges
110
Sponges first hypothesis?
earliest animals to appear in the fossil record
111
When did the first sponge appear?
more than 700 million years ago
112
what is consistent with basal position of sponges on phylogeny
presence of multicellular sponges and absence of fossils of other multicellular organisms
113
Sponges share characteristics with
choanoflagellates
114
bothe sponges and choanoflagellates
- are benthic (live at bottom of body of water) and sessile (immobile)
- both feed using cells with nearly identical morphology
115
differences between choanoflagellates and sponges
- sponges may contain many specialized type of cells which are dependent on each other
116
choanoflagellates sometimes form _____
colonies
117
sponges were once considered
colonies of single celled protists
118
two major types of embryonic tissue layers
dipoblasty
triplobasty
119
dipoblasts?
animals whose embryos have two types of tissues or germ layers
120
type of germ layers in dipoblasts
ectoderm
endoderm
121
germ layers develop into
distinct adult tissues and organs
122
triploblasts?
are animals whose embryos have three germ layers
123
types of germ layers in tripoblasts
ectoderm
endoderm
mesoderm
124
what is shared between diplo and tripo blasty
- mesoderm-like cells in mesonlea
- genes coding for structural components of mesodermal cells
- some can change the shape of their bodies
- actin and myosin
125
what is missing in dipoblasts that can be found in tripoblasts
mesodermal specification genes
well- defined mesoderm
true muscles
126
body symmetry -
key morphological aspect of animal's body plan
127
Radial symmetry?
symmetry around a central axis
symmetrical on multiple planes
128
most animals exibit which type of symmetry
bilateral symmety
129
what is bilateral symmetry
a single plane of symmetry
130
WHICH symmetry eveolved first
radial symmetry appears to have evolved earlier than bilateral symmetry
131
ALL __________ are bilaterally symmetric
triploblasts
except starfish!
132
bilaterians?
are triploblastic, bilaterally symmetrical animals
133
symmetry in bilaterians results from action of
hox genes
decaoentaplegic
134
Biologists hypothesized that bilateral symmetry seen in some cnidarians is homologous
to bilateral symmetry in bilaterians
135
Some parts of genetic tool kit for bilateral symmetry arose
before cnidarian
and bilaterian lineages split
136
symmetry and _____ _____ are related
nervous system
137
sponges lack
nerve cells and symmetry
138
evolution of central system coincided with
cephalization
139
basic bilaterian body shape is a
tube within a tube
140
what are the parts in the tube within a tube body plan
inner tube
outer tube
mesoderm
141
coelom?
is an enclosed, fluid filled body cavity between the tubes
142
benefits of coelom
1. enables the internal organs to move independently of each other
2. mprovides a space for oxygen and nutrients to circulate
143
true coelomates
coelom is completely lined with mesoderm
144
acoelomates
no cavity form
no coelom, such as the flatworm
145
Pseudocoelomates
Coelom is only partially lined with mesoderm, such as roundworms (phylum
Nematoda) and rotifers
146
Evolutionary flexibility of coelom has ...
reduced its usefulness as a synapomorphy for bilaterian animals
147
common ancestor of protostomes and deterostomes 1
Common ancestor during Cambrian was likely bilaterally symmetric triploblast with CNS, cephalization, and coelom
148
Protostomes
, (“first-mouth”), named for embryonic development of mouth before anus
149
Deuterostomes,
(“second-mouth”), named for embryonic development of
anus before mouth
150
traditional vs recent view of protostomes
▪ Traditional view: In protostomes, blastopore becomes mouth and anus forms
later
▪ Recent view: Development is highly variable in protostomes—blastopore may
become anus, mouth, both anus and mouth, or neither
151
segmentation
division of body or part of body into series of similar structures
152
what is one of the defining characteristics of vertebrates
segmented backbone
153
invertebrates are what type of clade
paraphyletic group
154
vertebrates are what type of clade
monophyletic
155
Segmentation enables....
specialization
156
Animals within lineage with similar body plan may
pursue different food sources and feeding strategies if their niche
differs
157
* Conversely, animals from different lineages with similar niches
often pursue the same food sources andfeeding
strategies
158
Detritivores
Feed on dead
organic matter
159
Herbivores
Feed on plants
or algae
160
Carnivores
Feed on animals
161
Omnivores
Feed on a
combination of
plants, animals,
fungi, protists,
archaea and/or
bacteria
162
Parasites
harvest nutrients from parts of their hosts
are usually smaller than their victims
163
Endoparasites
live inside their hosts and usually have simple, wormlike bodies
164
Ectoparasites
live outside their hosts and usually have limbs or mouthparts that allow them to grasp the host
165
Suspension feeders
Capture food by filtering
out particles floating in
water or drifting through
the air
166
Deposit feeders
Ingest organic material
that has been deposited
within a substrate or on
its surface
167
Fluid feeders
Suck or mop up liquids
like nectar, plant sap,
blood, or fruit juice
168
Deposit feeders
Ingest organic material
that has been deposited
within a substrate or on
its surface
169
Mass feeders
Take chunks of food
into their mouths
170
Key aspect of cephalization:
* Concentration of sensory organs in head region
* Great deal of diversity of sensory abilities and structures among the animals
171
Most animals also have some ability
to sense temperature
172
how many types of skeletal systems are there and what are they
three
hydrostatic skeleton
endoskeleton
exoskeleton
173
Hydrostatic skeletons:
support from flexible body wall in tension surrounding
fluid or soft tissue under compression
174
Endoskeletons
derive support from rigid structures inside the body, such as
bones in vertebrates and spicules in sponges
175
Exoskeletons
derive support from rigid structures on the outside of the body, such
as the external armor of arthropods
176
types of limbs
lobe like limbs
parapodia
arms and tentacles
tube feet
jointed limbs
177
External fertilization is associated
with water
178
internal fertilization is related to
land
179
Ovoviviparous
eggs + live bearing
180
viviparous
live bearing
181
oviparous
egg bearing
182
when did the animal phyla EXPLODE
cambrian explosion
183
what is a special feature of the cambrian period
diversity of body types
184
most sexually reproducing animals have ...
diploid dominant life cycles
185
metamorphosis
drastic change from one developmental stage to another
186
metamorphosis contrast with
direct developement where an animal is born essentially as a smaller version of the adult form
187
INdirect development of metamorphisis
:
– Embryogenesis produces larvae (larva), which:
Look radically different from adults
Live in different habitats and eat different foods
– Metamorphosis transforms larvae into juveniles, which:
Look like adults
Live in the same habitats and eat the same foods
Are still sexually immature
– Growth and maturation transform the juveniles into adults—reproductive
stage in life cycle
188
Fossil record and phylogeny of animals agree that
– Porifera (sponges)
– Ctenophora (comb jellies) and
– Cnidaria (jellyfish and others)
are most ancient of all
major animal lineages
189
Porifera (sponges), Ctenophora (comb jellies), Cnidaria all have
global marine distribution
190
what are the five major animal lineages
Sponges
-Comb jellies
-Corals and jellyfish
-Protostomes - deuterostomes
| SOMEONE DOUBLE CHECK THIS
191
what ratio of the animal phyla are prostomes
22/30
192
what are some roles that protostomes fill
- Live in virtually every aquatic and terrestrial habitat
– Can be detritivores, herbivores, or carnivores
– Ecological importance of protostomes extends to human health
193
two major subgroups of protostomes
lophotrochozoans and ecdysozoans
194
protostome phyla have what kind of diversity
ALL KINDs, some have very little species and some have very many species
195
Fossils indicate protostomelineages originated
in the ocean
196
HOW many times did protosomes make transition from aquatic to terrestrial environments
MULTIPLE TIME
197
Most protostome lineages, especially snails (Mollusca) and Arthropoda, survived on land and experienced ....
– Experience adaptive radiation
198
what is adaptive radiation
Period of rapid speciation
199
200
why transition to land
ecological opportunity--> open up entirely new habitats and new resourcers to exploit
201
protostomes transition to land coincided with
adaptive raditation of plants on land
202
land plant thrive in
increased availability pf sunlight and co2 on land compared to water which resulted in high net primary productivity of land plants
203
what are the challenged of land transitions
1. Exchange gases
2. Avoid drying out
3. Hold up their bodies under their own weight
204
why are protosomes important
– Major direct source of food for humans (seafood!)
– Provide ecosystem services (pollination!)
– Some damage crops (pests)
– Some produce materials such as silk and pearls
– Cause or transmit human diseases and are parasites
(mosquitoes, ticks, etc)
– Include two of the most important model organisms:
Fruit fly Drosophila melanogaster and roundworm
Caenorhabditis elegans
205
key innovations in round worms and earthworms to adapt to land
- Have high surface-area-to-volume ratio
– Increases efficiency of gas exchange across their body
surface in their moist environments
206
Terrestrial arthropods and mollusks adaptations to land?
-Have gills or other respiratory structures located inside
the body
– Minimizes water loss when moving onto land
207
key innovations in insects to move to land
evolved a waxy layer to minimize water loss from body surface (cuticle)
– If environment dries, openings to respiratory passages
can be closed
208
Desiccation-resistant eggs evolved ....
Evolved repeatedly in populations that made transition
to life on land
209
Modular body plans allow for
phenotypic innovation through minor expression changes
210
Protostomes such as mollusks and arthropods have
compartmentalized body
plans
211
compartmentalized body
plans is a key inovation for
evolutionary flexibility
212
Mechanism for dramatic diversification in new ecological contexts:
Gene expression of regulatory genes
– Produce structural and functional innovation
– Example: Hox genes
213
What are lophotrochozoans
Monophyletic group—all descendants of common ancestor
* 13 phyla include rotifers, flatworms, annelids, and mollusks
214
key feactures of lophotrochozoans
lophophore (ring of cilia) and
trochophore (ring of cilia but for larvae)
215
lophophore?
Specialized structure that rings mouth of these animals and functions in suspension
feeding
216
trochophore
Type of larva common to several phyla of lophotrochozoa (has a ring of cilia)
217
Trochophore larvae have a ______ ____ ______ around their middle that functions in sweeping
and, sometimes, in feeding
ring of cilia
218
Trochophore larvae occur in animals that undergo
indirect development
219
Trochophore larvae originated early in
Originated early evolution of lophotrochozoans:
Later evolved into different larval types in some groups
220
Lophotrochozoans possess what type of cleavage
spiral cleavage
221
what is a synapomorphy in Lophotrochozoans
spiral cleavage
222
spiral cleavage is
When cells divide at oblique angles,
spiraling pattern of cells in blastula
results
223
– Spiral cleavage has been _________ ____________ in some lophotrochozoan
phyla, but has been ...
highly conserved, modified or lost in others
224
Cuticle and exoskeleton?
– Protect these animals from predators
– Provide an effective structure for muscle attachment
225
During molting,
animal’s soft body is exposed and vulnerable:
226
ecdysone
is a hormone important in regulation of molting cycle
227
Lophotrochozoans and Ecdysozoans Differ
in Their Mechanism of Growth.
228
Ecdysozoans grow
intermittently by molting:
– Shedding of the soft cuticle or hard exoskeleton
229
Ecdysozoans undergo ______________ as they grow
succession of molts
230
what can happen during molts of ecdysozoans
Sometimes dramatic morphological transformations occur during these
molts
