Transcript File - jj-sct

CAMPBELL
BIOLOGY
TENTH
EDITION
Reece • Urry • Cain • Wasserman • Minorsky • Jackson
31
Fungi
Clicker Questions by
Roberta Batorsky
© 2014 Pearson Education, Inc.
You are presented with several single-celled
organisms, including one thought to belong to the
kingdom Fungi. What unique feature helps you identify
the fungus?
a) presence of mitochondria
b) absence of chloroplasts
c) presence of nuclei
d) presence of chitinous cell walls
© 2014 Pearson Education, Inc.
You are presented with several single-celled
organisms, including one thought to belong to the
kingdom Fungi. What unique feature helps you identify
the fungus?
a) presence of mitochondria
b) absence of chloroplasts
c) presence of nuclei
d) presence of chitinous cell walls
© 2014 Pearson Education, Inc.
Which phylogenetic tree represents the evolutionary
history of the fungi based on the most recent data?
a)
c)
b)
d)
© 2014 Pearson Education, Inc.
Which phylogenetic tree represents the evolutionary
history of the fungi based on the most recent data?
a)
c)
b)
d)
© 2014 Pearson Education, Inc.
You are given a fungus to identify. It has a fruiting body
that contains many structures with eight haploid spores
lined up in a row. What kind of fungus is this?
a) zygomycete
b) chytrid
c) deuteromycete
d) ascomycete
© 2014 Pearson Education, Inc.
You are given a fungus to identify. It has a fruiting body
that contains many structures with eight haploid spores
lined up in a row. What kind of fungus is this?
a) zygomycete
b) chytrid
c) deuteromycete
d) ascomycete
© 2014 Pearson Education, Inc.
Many fungi produce antibiotics, for example, penicillin,
that are effective at stopping bacterial growth. Which do
you think is the evolutionary advantage to the fungus of
secreting antibacterial chemicals?
a) defense: preventing bacteria from infecting the fungus
b) defense: preventing bacteria from killing fungal spores
c) symbiosis: attracting helpful bacteria
d) competition: destroying bacteria that compete
for their food
e) predation: eventually consuming the bacteria
© 2014 Pearson Education, Inc.
Many fungi produce antibiotics, for example, penicillin,
that are effective at stopping bacterial growth. Which do
you think is the evolutionary advantage to the fungus of
secreting antibacterial chemicals?
a) defense: preventing bacteria from infecting the fungus
b) defense: preventing bacteria from killing fungal spores
c) symbiosis: attracting helpful bacteria
d) competition: destroying bacteria that compete
for their food
e) predation: eventually consuming the bacteria
© 2014 Pearson Education, Inc.
Which of the following phyla includes aquatic,
flagellated fungi?
a) Ascomycota
b) Basidiomycota
c) Chytridiomycota
d) Zygomycota
© 2014 Pearson Education, Inc.
Which of the following phyla includes aquatic,
flagellated fungi?
a) Ascomycota
b) Basidiomycota
c) Chytridiomycota
d) Zygomycota
© 2014 Pearson Education, Inc.
Which of the following statements about mycorrhizae
is false?
a) They are important in natural systems and
agriculture.
b) Almost all vascular plants have them.
c) Foresters inoculate pine seedlings with them to
promote growth.
d) They colonize soils by dispersing spores that form
new mycelia.
e) They are in a commensalistic relationship with
plants.
© 2014 Pearson Education, Inc.
Which of the following statements about mycorrhizae
is false?
a) They are important in natural systems and
agriculture.
b) Almost all vascular plants have them.
c) Foresters inoculate pine seedlings with them to
promote growth.
d) They colonize soils by dispersing spores that form
new mycelia.
e) They are in a commensalistic relationship with
plants.
© 2014 Pearson Education, Inc.
All of the following are lineages of fungi except
a) chytrids.
b) zygomycetes.
c) glomeromycetes.
d) ascomycetes.
e) conidia.
© 2014 Pearson Education, Inc.
All of the following are lineages of fungi except
a) chytrids.
b) zygomycetes.
c) glomeromycetes.
d) ascomycetes.
e) conidia.
© 2014 Pearson Education, Inc.
Lichens are
a) mutually beneficial relationships between fungi and
plant roots.
b) symbiotic associations between photosynthetic
organisms and fungi.
c) a type of plant pathogen.
d) a type of marine eukaryote.
e) single-celled, flagellated protist ancestors of fungi.
© 2014 Pearson Education, Inc.
Lichens are
a) mutually beneficial relationships between fungi and
plant roots.
b) symbiotic associations between photosynthetic
organisms and fungi.
c) a type of plant pathogen.
d) a type of marine eukaryote.
e) single-celled, flagellated protist ancestors of fungi.
© 2014 Pearson Education, Inc.
Chytrids are unique among fungi in that they
a) have flagellated spores
b) form mutualistic relationships with amphibians
c) have led to the decline of sheep and cattle
populations
d) have chitinous cell walls
© 2014 Pearson Education, Inc.
Chytrids are unique among fungi in that they
a) have flagellated spores
b) form mutualistic relationships with amphibians
c) have led to the decline of sheep and cattle
populations
d) have chitinous cell walls
© 2014 Pearson Education, Inc.
The practical uses of fungi include all of the following
except
a) systemic mycoses.
b) reducing high blood pressure.
c) stopping maternal bleeding after childbirth.
d) treating bacterial infections.
e) fuel production.
© 2014 Pearson Education, Inc.
The practical uses of fungi include all of the following
except
a) systemic mycoses.
b) reducing high blood pressure.
c) stopping maternal bleeding after childbirth.
d) treating bacterial infections.
e) fuel production.
© 2014 Pearson Education, Inc.
Scientific Skills Exercises
The first genome of a mycorrhizal fungus to be sequenced was that of
the basidiomycete Laccaria bicolor. In nature, L. bicolor is a common
ectomycorrhizal fungus of trees such as poplar and fir, as well as a freeliving soil organism. In forest nurseries, it is used in large-scale
inoculation programs to enhance seedling growth. The fungus can easily
be grown alone in culture and can establish mycorrhizae with tree roots
in the laboratory. Researchers hope that studying the genome of L.
bicolor will yield clues to the processes by which it interacts with its
mycorrhizal partners--and by extension, to mycorrhizal interactions
involving other fungi.
Using the whole-genome shotgun method and bioinformatics,
researchers sequenced the genome of L. bicolor and compared it with
the genomes of some nonmycorrhizal basidiomycete fungi. By analyzing
gene expression using microarrays, the researchers were able to
compare gene expression levels for different protein-coding genes and
for the same genes in a mycorrhizal mycelium and a free-living
mycelium. They could thus identify the genes for fungal proteins that are
made specifically in mycorrhizae.
© 2014 Pearson Education, Inc.
Based on the table, which fungal species has the
most genes encoding membrane transporters
(membrane transport proteins)?
a) L. bicolor
b) nonmycorrhizal
species 1
c) nonmycorrhizal
species 2
d) nonmycorrhizal
species 3
e) nonmycorrhizal
species 4
© 2014 Pearson Education, Inc.
Based on the table, which fungal species has the
most genes encoding membrane transporters
(membrane transport proteins)?
a) L. bicolor
b) nonmycorrhizal
species 1
c) nonmycorrhizal
species 2
d) nonmycorrhizal
species 3
e) nonmycorrhizal
species 4
© 2014 Pearson Education, Inc.
Why might you expect to find many genes for membrane
transporters in a mycorrhizal fungus such as L. bicolor?
a) Mycorrhizal fungi exchange nutrients with the roots of
their plant hosts and would be expected to use
membrane transporters in this exchange.
b) The numerous chemical reactions that involve
mycorrhizal fungi and their plant hosts are catalyzed by
membrane transport proteins that function as enzymes.
c) Complex chemical communication occurs between
mycorrhizal fungi and their plant hosts, and membrane
transporters are crucial in this process.
d) Special junctions form between the cells of plant roots
and mycorrhizal fungi, and membrane transporters are
an important structural part of these junctions
© 2014 Pearson Education, Inc.
Why might you expect to find many genes for membrane
transporters in a mycorrhizal fungus such as L. bicolor?
a) Mycorrhizal fungi exchange nutrients with the roots
of their plant hosts and would be expected to use
membrane transporters in this exchange.
b) The numerous chemical reactions that involve
mycorrhizal fungi and their plant hosts are catalyzed by
membrane transport proteins that function as enzymes.
c) Complex chemical communication occurs between
mycorrhizal fungi and their plant hosts, and membrane
transporters are crucial in this process.
d) Special junctions form between the cells of plant roots
and mycorrhizal fungi, and membrane transporters are
an important structural part of these junctions
© 2014 Pearson Education, Inc.
The researchers used the phrase “small secreted proteins”
(SSPs) to refer to proteins less than 100 amino acids in
length that the fungi secrete; their function is not yet known.
What is most striking about the SSP data from the table?
a) The number of genes for SSPs is much higher for
L. bicolor than for the other species tested.
b) L. bicolor is the only fungus tested that has more
genes for SSPs than genes for membrane
transporters.
c) All the species tested have approximately the same
number of genes for SSPs.
d) The number of genes for SSPs is much lower for
L. bicolor than for the other species tested.
© 2014 Pearson Education, Inc.
The researchers used the phrase “small secreted proteins”
(SSPs) to refer to proteins less than 100 amino acids in
length that the fungi secrete; their function is not yet known.
What is most striking about the SSP data from the table?
a) The number of genes for SSPs is much higher for
L. bicolor than for the other species tested.
b) L. bicolor is the only fungus tested that has more
genes for SSPs than genes for membrane
transporters.
c) All the species tested have approximately the same
number of genes for SSPs.
d) The number of genes for SSPs is much lower for
L. bicolor than for the other species tested.
© 2014 Pearson Education, Inc.
The SSP genes shared a common feature that indicated
the encoded proteins were destined for secretion. Genes
for secretory proteins have a signal-peptide coding
sequence at the leading end. The signal peptide at or near
the leading end of the polypeptide targets the protein to the
ER. Which of the following is a plausible hypothesis for the
roles of SSPs in mycorrhizae.
a) SSPs are proteins secreted by mycorrhizal fungi.
b) SSPs in mycorrhizal species allow specific substances
from the soil to cross a cell membrane.
c) The function of SSPs in mycorrhizal species is likely to be
the same as in nonmycorrhizal species.
d) SSPs play important roles in the mycorrhizal
interaction.
© 2014 Pearson Education, Inc.
The SSP genes shared a common feature that indicated
the encoded proteins were destined for secretion. Genes
for secretory proteins have a signal-peptide coding
sequence at the leading end. The signal peptide at or near
the leading end of the polypeptide targets the protein to the
ER. Which of the following is a plausible hypothesis for the
roles of SSPs in mycorrhizae.
a) SSPs are proteins secreted by mycorrhizal fungi.
b) SSPs in mycorrhizal species allow specific substances
from the soil to cross a cell membrane.
c) The function of SSPs in mycorrhizal species is likely to be
the same as in nonmycorrhizal species.
d) SSPs play important roles in the mycorrhizal
interaction.
© 2014 Pearson Education, Inc.
The table in the following slide shows data from gene expression
studies for the four L. bicolor genes whose transcription was most
increased (“upregulated”) in mycorrhizae. For the gene encoding the
first protein listed, what does the number 22,877 indicate?
a) The amount of RNA transcript of this gene made in Douglas fir
mycorrhizae was 22,877 times higher than the amount made in
poplar mycorrhizae.
b) The amount of RNA transcript of this gene made in mycorrhizal
parts of the fungus when associated with Douglas fir was 22,877
times higher than the amount made in soil mycelium away from
plant roots.
c) The amount of RNA transcript of this gene made in poplar
mycorrhizae was 22,877 times higher than the amount made in
Douglas fir mycorrhizae.
d) The amount of RNA transcript of this gene made in soil mycelium
away from plant roots was 22,877 times higher than the amount
made in mycorrhizal parts of the fungus associated with Douglas fir.
© 2014 Pearson Education, Inc.
© 2014 Pearson Education, Inc.
The table in the previous slide shows data from gene expression
studies for the four L. bicolor genes whose transcription was most
increased (“upregulated”) in mycorrhizae. For the gene encoding the
first protein listed, what does the number 22,877 indicate?
a) The amount of RNA transcript of this gene made in Douglas fir
mycorrhizae was 22,877 times higher than the amount made in
poplar mycorrhizae.
b) The amount of RNA transcript of this gene made in mycorrhizal
parts of the fungus when associated with Douglas fir was
22,877 times higher than the amount made in soil mycelium
away from plant roots.
c) The amount of RNA transcript of this gene made in poplar
mycorrhizae was 22,877 times higher than the amount made in
Douglas fir mycorrhizae.
d) The amount of RNA transcript of this gene made in soil mycelium
away from plant roots was 22,877 times higher than the amount
made in mycorrhizal parts of the fungus associated with Douglas fir.
© 2014 Pearson Education, Inc.
Do the data in the table support the hypothesis that SSPs
play important roles in the mycorrhizal interaction?
a) Yes, because a majority of SSPs in the L. bicolor genome
are upregulated in the ectomycorrhizal mycelium.
b) No, because two of the most upregulated genes in the
ectomycorrhizal mycelium encode an enzyme and an
enzyme inhibitor rather than SSPs.
c) No, because it is impossible to draw a conclusion based
on data from only four genes when L. bicolor has a total of
2,191 genes for SSPs.
d) Yes, because two of the most upregulated genes in the
ectomycorrhizal mycelium encode SSPs.
© 2014 Pearson Education, Inc.
Do the data in the table support the hypothesis that SSPs
play important roles in the mycorrhizal interaction?
a) Yes, because a majority of SSPs in the L. bicolor genome
are upregulated in the ectomycorrhizal mycelium.
b) No, because two of the most upregulated genes in the
ectomycorrhizal mycelium encode an enzyme and an
enzyme inhibitor rather than SSPs.
c) No, because it is impossible to draw a conclusion based
on data from only four genes when L. bicolor has a total of
2,191 genes for SSPs.
d) Yes, because two of the most upregulated genes in
the ectomycorrhizal mycelium encode SSPs.
© 2014 Pearson Education, Inc.
How do the data for poplar tree mycorrhizae compare
with those for Douglas fir mycorrhizae?
a) All four genes are more upregulated in poplar
mycorrhizae than in Douglas fir mycorrhizae.
b) All four genes are more upregulated in Douglas fir
mycorrhizae than in poplar mycorrhizae.
c) Some of the genes that are upregulated in Douglas fir
mycorrhizae are downregulated in poplar mycorrhizae
and vice versa.
d) The four genes are all upregulated in the
mycorrhizae of both trees, but the relative
amounts of upregulation differ.
© 2014 Pearson Education, Inc.
© 2014 Pearson Education, Inc.
How do the data for poplar tree mycorrhizae compare
with those for Douglas fir mycorrhizae?
a) All four genes are more upregulated in poplar
mycorrhizae than in Douglas fir mycorrhizae.
b) All four genes are more upregulated in Douglas fir
mycorrhizae than in poplar mycorrhizae.
c) Some of the genes that are upregulated in Douglas fir
mycorrhizae are downregulated in poplar mycorrhizae
and vice versa.
d) The four genes are all upregulated in the
mycorrhizae of both trees, but the relative
amounts of upregulation differ.
© 2014 Pearson Education, Inc.
Which of the following is the most plausible hypothesis
to explain the differences in gene expression between
poplar tree mycorrhizae and Douglas fir mycorrhizae?
a) Poplars, but not Douglas firs, have turned off the
expression of some L. bicolor SSP genes.
b) Differences in the trees’ environments affect which
genes are expressed most.
c) Poplars need more enzyme inhibitors, but fewer
enzymes and SSPs, than Douglas firs.
d) The two types of trees are associated with different
species of mycorrhizal symbionts, which have
different patterns of gene expression.
© 2014 Pearson Education, Inc.
Which of the following is the most plausible hypothesis
to explain the differences in gene expression between
poplar tree mycorrhizae and Douglas fir mycorrhizae?
a) Poplars, but not Douglas firs, have turned off the
expression of some L. bicolor SSP genes.
b) Differences in the trees’ environments affect
which genes are expressed most.
c) Poplars need more enzyme inhibitors, but fewer
enzymes and SSPs, than Douglas firs.
d) The two types of trees are associated with different
species of mycorrhizal symbionts, which have
different patterns of gene expression.
© 2014 Pearson Education, Inc.