BIO 1108 EXAM 2 (HERRICK) PRACTICE QUESTIONS
COMPLETE WITH ANSWERS AND RATIONALES
Question 1
A researcher discovers a new species of fungi that form hyphae but not
septa. This fungus also lacks multicellular fruiting bodies and does not
appear to form either endomycorrhizae or ectomycorrhizae with plants.
How should this fungus be classified?
A) Ascomycetes
B) Basidiomycetes
C) Zygomycetes
D) Glomeromycetes
Answer: C) Zygomycetes
Rationale: Zygomycetes are characterized by hyphae that lack septa
(coenocytic hyphae), do not typically form complex multicellular fruiting
bodies, and do not form mycorrhizal associations with plants.
Ascomycetes and Basidiomycetes have septate hyphae, while
Glomeromycetes form endomycorrhizae.
Question 2
A researcher is looking at different Petri dishes containing the yeast C.
albicans. In the first dish she evaluates, she notices that the yeast do
not form hyphae. Is this a mutant strain of yeast?
,A) Yes, because all yeasts can form hyphae under appropriate
conditions
B) No, as yeasts do not normally form hyphae
C) Yes, because C. albicans always forms hyphae
D) No, because hyphae formation requires bacterial co-culture
Answer: B) No, as yeasts do not normally form hyphae
Rationale: Yeasts are unicellular fungi that typically reproduce by
budding and do not normally form hyphae. C. albicans can form hyphae
under certain conditions, but the absence of hyphae does not indicate a
mutant strain.
Question 3
Abscisic acid is a hormone produced by root cap cells as soils dry. What
is its primary function?
A) Stimulates flowering and fruit development
B) Promotes cell elongation and root growth toward water
C) Stimulates root elongation and triggers stomata to close, reducing
demand for water
D) Inhibits seed germination and promotes leaf abscission
Answer: C) Stimulates root elongation and triggers stomata to close,
reducing demand for water
Rationale: ABA is produced in root cap cells in response to soil drying. It
stimulates root elongation to reach deeper water sources and causes
stomatal closure to reduce transpiration and water loss, effectively
reducing the plant's demand for water.
,Question 4
What adaptation in grasses allows them to recover after grazing?
A) Deep taproots that store carbohydrates
B) Stems are short with apical meristems close to the ground and leaves
that are tightly imbricated and continue to grow from the base
C) Production of toxic alkaloids that deter herbivores
D) Rapid seed production before grazing occurs
Answer: B) Stems are short with apical meristems close to the ground
and leaves that are tightly imbricated and continue to grow from the
base
Rationale: Grasses have evolved adaptations to grazing including short
stems that keep apical meristems near the ground where they are less
likely to be removed, tightly overlapping leaves that protect growing
points, and basal meristems that allow continued growth after the
upper portions are consumed.
Question 5
Alkaloids are chemical defenses that:
A) Disrupt cell wall synthesis in herbivores
B) Are nitrogen-bearing compounds that damage the nervous system of
animals
C) Inhibit digestive enzymes in herbivorous insects
D) Attract predators that consume herbivores
, Answer: B) Are nitrogen-bearing compounds that damage the nervous
system of animals
Rationale: Alkaloids are nitrogen-containing compounds that act as
chemical defenses by affecting the nervous systems of animals that
consume them. Examples include atropine, codeine, morphine, quinine,
and ephedrine.
Question 6
What makes alkaloids a costly defense for plants?
A) They require large amounts of carbon to synthesize
B) Their nitrogen richness prevents plants from building proteins for
photosynthesis
C) They require specialized transport tissues
D) They attract more herbivores than they deter
Answer: B) Their nitrogen richness prevents plants from building
proteins for photosynthesis
Rationale: Alkaloids contain nitrogen, which is a limiting nutrient for
plants. The investment of nitrogen into alkaloid production represents a
cost because that nitrogen could otherwise be used for proteins needed
for photosynthesis and growth.
Question 7
The alternation of generations in plants involves:
COMPLETE WITH ANSWERS AND RATIONALES
Question 1
A researcher discovers a new species of fungi that form hyphae but not
septa. This fungus also lacks multicellular fruiting bodies and does not
appear to form either endomycorrhizae or ectomycorrhizae with plants.
How should this fungus be classified?
A) Ascomycetes
B) Basidiomycetes
C) Zygomycetes
D) Glomeromycetes
Answer: C) Zygomycetes
Rationale: Zygomycetes are characterized by hyphae that lack septa
(coenocytic hyphae), do not typically form complex multicellular fruiting
bodies, and do not form mycorrhizal associations with plants.
Ascomycetes and Basidiomycetes have septate hyphae, while
Glomeromycetes form endomycorrhizae.
Question 2
A researcher is looking at different Petri dishes containing the yeast C.
albicans. In the first dish she evaluates, she notices that the yeast do
not form hyphae. Is this a mutant strain of yeast?
,A) Yes, because all yeasts can form hyphae under appropriate
conditions
B) No, as yeasts do not normally form hyphae
C) Yes, because C. albicans always forms hyphae
D) No, because hyphae formation requires bacterial co-culture
Answer: B) No, as yeasts do not normally form hyphae
Rationale: Yeasts are unicellular fungi that typically reproduce by
budding and do not normally form hyphae. C. albicans can form hyphae
under certain conditions, but the absence of hyphae does not indicate a
mutant strain.
Question 3
Abscisic acid is a hormone produced by root cap cells as soils dry. What
is its primary function?
A) Stimulates flowering and fruit development
B) Promotes cell elongation and root growth toward water
C) Stimulates root elongation and triggers stomata to close, reducing
demand for water
D) Inhibits seed germination and promotes leaf abscission
Answer: C) Stimulates root elongation and triggers stomata to close,
reducing demand for water
Rationale: ABA is produced in root cap cells in response to soil drying. It
stimulates root elongation to reach deeper water sources and causes
stomatal closure to reduce transpiration and water loss, effectively
reducing the plant's demand for water.
,Question 4
What adaptation in grasses allows them to recover after grazing?
A) Deep taproots that store carbohydrates
B) Stems are short with apical meristems close to the ground and leaves
that are tightly imbricated and continue to grow from the base
C) Production of toxic alkaloids that deter herbivores
D) Rapid seed production before grazing occurs
Answer: B) Stems are short with apical meristems close to the ground
and leaves that are tightly imbricated and continue to grow from the
base
Rationale: Grasses have evolved adaptations to grazing including short
stems that keep apical meristems near the ground where they are less
likely to be removed, tightly overlapping leaves that protect growing
points, and basal meristems that allow continued growth after the
upper portions are consumed.
Question 5
Alkaloids are chemical defenses that:
A) Disrupt cell wall synthesis in herbivores
B) Are nitrogen-bearing compounds that damage the nervous system of
animals
C) Inhibit digestive enzymes in herbivorous insects
D) Attract predators that consume herbivores
, Answer: B) Are nitrogen-bearing compounds that damage the nervous
system of animals
Rationale: Alkaloids are nitrogen-containing compounds that act as
chemical defenses by affecting the nervous systems of animals that
consume them. Examples include atropine, codeine, morphine, quinine,
and ephedrine.
Question 6
What makes alkaloids a costly defense for plants?
A) They require large amounts of carbon to synthesize
B) Their nitrogen richness prevents plants from building proteins for
photosynthesis
C) They require specialized transport tissues
D) They attract more herbivores than they deter
Answer: B) Their nitrogen richness prevents plants from building
proteins for photosynthesis
Rationale: Alkaloids contain nitrogen, which is a limiting nutrient for
plants. The investment of nitrogen into alkaloid production represents a
cost because that nitrogen could otherwise be used for proteins needed
for photosynthesis and growth.
Question 7
The alternation of generations in plants involves:
