BSC2011 Exam 1 Questions and All
Correct Answers 2026 Updated.
28.1 How can the steps in the table be ordered to describe a plant's response to an invading
pathogen? - Answer 2, 5, 4, 1, 3
28.1 Which action could help a biologist determine whether a particular plant population had
been attacked by a bacterial pathogen in the recent past? - Answer Look for elevated levels of
mRNA transcripts for PR proteins in tissues of plants sampled across the population.
28.1 Plants of different species showed different responses to the same pathogen as
summarized in the table above. Which of the following hypotheses best explains all of the
observations? - Answer Species B is able to defend against the pathogen with a hypersensitive
response, whereas species A does not mount this defense.
28.1 In systemic acquired resistance, which molecule is transported throughout the plant? -
Answer Salicylic acid
25.3 Which would you expect to increase the rate of water transport in a plant? - Answer A
rise in temperature
25.3 According to the current model of fluid flow in xylem, what creates the force that moves
water from the roots to the leaves? - Answer An increase in water tension in leaves
25.3 Where does the energy come from that drives water transport in plants? - Answer The
sun
25.3 What structures allow water vapor to escape the leaves of a plant? - Answer Stomata
25.4 Movement of sucrose and other carbohydrates through the phloem in a plant is called -
Answer translocation.
25.4 The flowchart describes the mechanism underlying fluid flow in phloem. Which phrases
best fill in the blanks? - Answer A = Water movement by osmosis; B = Pressure increase
25.4 In the spring, a plant grows from a root system that had been dormant throughout the
winter. The plant produces a stem, several branches, leaves, and begins to flower. The relative
concentrations of sucrose in cells of various organs of the plant are shown in the table. How
would you describe the fluid pressure in the plant phloem at this time? - Answer Highest in
root and lowest in flower bud
, 25.4 Which of the following statements about the pressure flow model of fluid flow in phloem is
true? - Answer Sucrose concentrations determine the direction of the fluid flow.
27.1 In an angiosperm, a megaspore mother cell is _______ and undergoes _______ to produce
four haploid (n) megaspores. - Answer diploid (2n); meiosis
27.1 In a female reproductive organ of an angiosperm, a multinucleate structure with eight
haploid nuclei forms. This structure is known as the - Answer embryo sac.
27.1 What evolutionary advantage might be gained by a plant carrying out double fertilization
instead of single fertilization? - Answer The plant conserves energy by producing a food source
for zygotes only when zygotes are successfully formed.
27.1 If you were to analyze the source of the genetic material in an angiosperm endosperm,
what ratio of maternal to paternal material would you find? - Answer 2:1
26.2 A biologist isolates cells that are not actively producing auxin from a section of a plant
stem. She places them in a culture dish with a growth medium that keeps the cells alive. When
she adds auxin to the dish, the cells begin synthesizing more cellulose. What is an alternative
that the biologist could add instead of auxin that would allow her to observe the same
response? - Answer acid
26.2 When a plant is illuminated from one side, auxin is transported to the _______ side of the
shoot, where it stimulates cells to _______, causing the shoot to bend toward the light. -
Answer dark; expand
26.2 A biologist investigating the response of a particular plant species to light cues stumbles
upon three mutant plant lines. Each displays a lack of normal phototropic behavior but varies in
the auxin concentrations present in their growing tips. Based on the information given in the
table, what could explain the behaviors of the three mutants? - Answer Mutant 1 is deficient
in an enzyme involved in auxin biosynthesis, whereas mutants 2 and 3 may have defective
expansin and/or proton pump proteins.
26.2 Which is the correct order of events during auxin-mediated cell elongation? - Answer
Proton pump gene expression → ATP hydrolysis → H+ movement into cell wall → expansin
activation
19.1 Morphologically, archaea differ from bacteria because they lack peptidoglycan molecules in
their cell walls. Archaea differ from eukarya because they lack a membrane-bound nucleus.
What can be concluded about when these two features evolved along the phylogenetic tree
Correct Answers 2026 Updated.
28.1 How can the steps in the table be ordered to describe a plant's response to an invading
pathogen? - Answer 2, 5, 4, 1, 3
28.1 Which action could help a biologist determine whether a particular plant population had
been attacked by a bacterial pathogen in the recent past? - Answer Look for elevated levels of
mRNA transcripts for PR proteins in tissues of plants sampled across the population.
28.1 Plants of different species showed different responses to the same pathogen as
summarized in the table above. Which of the following hypotheses best explains all of the
observations? - Answer Species B is able to defend against the pathogen with a hypersensitive
response, whereas species A does not mount this defense.
28.1 In systemic acquired resistance, which molecule is transported throughout the plant? -
Answer Salicylic acid
25.3 Which would you expect to increase the rate of water transport in a plant? - Answer A
rise in temperature
25.3 According to the current model of fluid flow in xylem, what creates the force that moves
water from the roots to the leaves? - Answer An increase in water tension in leaves
25.3 Where does the energy come from that drives water transport in plants? - Answer The
sun
25.3 What structures allow water vapor to escape the leaves of a plant? - Answer Stomata
25.4 Movement of sucrose and other carbohydrates through the phloem in a plant is called -
Answer translocation.
25.4 The flowchart describes the mechanism underlying fluid flow in phloem. Which phrases
best fill in the blanks? - Answer A = Water movement by osmosis; B = Pressure increase
25.4 In the spring, a plant grows from a root system that had been dormant throughout the
winter. The plant produces a stem, several branches, leaves, and begins to flower. The relative
concentrations of sucrose in cells of various organs of the plant are shown in the table. How
would you describe the fluid pressure in the plant phloem at this time? - Answer Highest in
root and lowest in flower bud
, 25.4 Which of the following statements about the pressure flow model of fluid flow in phloem is
true? - Answer Sucrose concentrations determine the direction of the fluid flow.
27.1 In an angiosperm, a megaspore mother cell is _______ and undergoes _______ to produce
four haploid (n) megaspores. - Answer diploid (2n); meiosis
27.1 In a female reproductive organ of an angiosperm, a multinucleate structure with eight
haploid nuclei forms. This structure is known as the - Answer embryo sac.
27.1 What evolutionary advantage might be gained by a plant carrying out double fertilization
instead of single fertilization? - Answer The plant conserves energy by producing a food source
for zygotes only when zygotes are successfully formed.
27.1 If you were to analyze the source of the genetic material in an angiosperm endosperm,
what ratio of maternal to paternal material would you find? - Answer 2:1
26.2 A biologist isolates cells that are not actively producing auxin from a section of a plant
stem. She places them in a culture dish with a growth medium that keeps the cells alive. When
she adds auxin to the dish, the cells begin synthesizing more cellulose. What is an alternative
that the biologist could add instead of auxin that would allow her to observe the same
response? - Answer acid
26.2 When a plant is illuminated from one side, auxin is transported to the _______ side of the
shoot, where it stimulates cells to _______, causing the shoot to bend toward the light. -
Answer dark; expand
26.2 A biologist investigating the response of a particular plant species to light cues stumbles
upon three mutant plant lines. Each displays a lack of normal phototropic behavior but varies in
the auxin concentrations present in their growing tips. Based on the information given in the
table, what could explain the behaviors of the three mutants? - Answer Mutant 1 is deficient
in an enzyme involved in auxin biosynthesis, whereas mutants 2 and 3 may have defective
expansin and/or proton pump proteins.
26.2 Which is the correct order of events during auxin-mediated cell elongation? - Answer
Proton pump gene expression → ATP hydrolysis → H+ movement into cell wall → expansin
activation
19.1 Morphologically, archaea differ from bacteria because they lack peptidoglycan molecules in
their cell walls. Archaea differ from eukarya because they lack a membrane-bound nucleus.
What can be concluded about when these two features evolved along the phylogenetic tree
