BIOD 102 MODULE 2 EXAM 2026/2027 | Essential
Biology II with Lab | Verified Q&A | Grade A |
Portage Learning | Pass Guaranteed - A+ Graded
SECTION 1: PLANT STRUCTURE & FUNCTION
Q1: Which vascular tissue is responsible for transporting water and dissolved minerals
from the roots to the aerial portions of the plant?
A. Phloem transports sugars and organic nutrients throughout the plant. [INCORRECT]
B. Xylem transports water and dissolved minerals from roots to shoots. [CORRECT]
C. The epidermis serves as the protective outer layer and does not conduct water.
[INCORRECT]
D. The cortex stores starch and facilitates radial transport but is not the primary
water-conducting tissue. [INCORRECT]
Correct Answer: B
Rationale: Xylem consists of tracheids and vessel elements that form hollow, lignified
tubes specialized for unidirectional water and mineral transport from roots to leaves via
transpiration pull. VERIFIED ✓ — Portage Learning BIOD 102 Module 2 Curriculum.
Q2: A botanist examines the root system of a mature oak tree and observes one large,
dominant vertical root with smaller lateral branches. This root system is classified as:
A. A fibrous root system composed of many thin, branching roots of similar diameter.
[INCORRECT]
B. A taproot system characterized by one large, dominant central root with lateral
branches. [CORRECT]
C. An adventitious root system arising from stems or leaves rather than the radicle.
[INCORRECT]
D. A prop root system that grows from the lower stem to provide structural support.
[INCORRECT]
Correct Answer: B
Rationale: Taproots feature a primary root that grows vertically downward and remains
dominant, with secondary roots branching laterally; this contrasts with fibrous systems
,where roots are roughly equal in size. VERIFIED ✓ — Portage Learning BIOD 102 Module
2 Curriculum.
Q3: In a cross-section of a dicot stem, vascular bundles are arranged in a distinct ring
pattern. How are vascular bundles typically arranged in a monocot stem?
A. In a ring pattern surrounding the pith, identical to dicot arrangement. [INCORRECT]
B. Scattered throughout the ground tissue without a defined ring. [CORRECT]
C. Concentrated only in the central pith region. [INCORRECT]
D. Arranged in a double ring with phloem interior and xylem exterior. [INCORRECT]
Correct Answer: B
Rationale: Monocot stems exhibit scattered vascular bundles embedded within the
ground tissue, whereas dicot stems organize vascular bundles in a distinct ring,
reflecting differences in vascular cambium activity and secondary growth capacity.
VERIFIED ✓ — Portage Learning BIOD 102 Module 2 Curriculum.
Q4: During a laboratory examination of a leaf cross-section, a student identifies the layer
of cells containing chloroplasts and responsible for most photosynthetic activity. This
layer is the:
A. Upper epidermis, which is transparent and lacks chloroplasts to allow light
penetration. [INCORRECT]
B. Palisade mesophyll, a columnar cell layer rich in chloroplasts and the primary site of
photosynthesis. [CORRECT]
C. Spongy mesophyll, which facilitates gas exchange but contains fewer chloroplasts
than the palisade layer. [INCORRECT]
D. Lower epidermis, which primarily houses stomata and guard cells for gas regulation.
[INCORRECT]
Correct Answer: B
Rationale: The palisade mesophyll consists of tightly packed, columnar parenchyma
cells containing the highest chloroplast density in the leaf, maximizing light capture for
photosynthesis. VERIFIED ✓ — Portage Learning BIOD 102 Module 2 Curriculum.
Q5: Which structural feature distinguishes primary growth from secondary growth in
woody plants?
A. Primary growth increases girth and diameter through lateral meristem activity.
[INCORRECT]
,B. Secondary growth increases length through apical meristem activity at root and
shoot tips. [INCORRECT]
C. Primary growth increases length through apical meristems, while secondary growth
increases girth through lateral meristems. [CORRECT]
D. Both primary and secondary growth occur exclusively at the tips of stems and roots.
[INCORRECT]
Correct Answer: C
Rationale: Primary growth is driven by apical meristems at root and shoot apices,
elongating the plant body, whereas secondary growth is driven by vascular and cork
cambiums (lateral meristems), adding woody tissue and increasing diameter. VERIFIED
✓ — Portage Learning BIOD 102 Module 2 Curriculum.
Q6: The cohesion-tension theory explains water movement in xylem primarily through
which mechanism?
A. Active transport of water molecules against their concentration gradient using ATP.
[INCORRECT]
B. Transpiration pull creating negative pressure, combined with hydrogen bonding
between water molecules and adhesion to xylem walls. [CORRECT]
C. Bulk flow driven by positive pressure generated in roots pushing water upward.
[INCORRECT]
D. Osmotic movement of water into phloem vessels at the source and out at the sink.
[INCORRECT]
Correct Answer: B
Rationale: Transpiration from leaf stomata creates negative pressure (tension) in xylem
vessels; water molecules cohere via hydrogen bonds and adhere to hydrophilic xylem
walls, enabling continuous upward movement without metabolic energy. VERIFIED ✓ —
Portage Learning BIOD 102 Module 2 Curriculum.
Q7: According to the pressure-flow hypothesis, translocation of sugars in phloem
occurs because:
A. Water potential gradients drive sugars from areas of high solute concentration
(sources) to low solute concentration (sinks) via bulk flow. [CORRECT]
B. Active transport of sucrose into xylem vessels creates a positive pressure gradient
that pushes water upward. [INCORRECT]
C. Transpiration pull generates negative pressure that draws sugars from leaves to
roots. [INCORRECT]
, D. Osmotic water movement into the source decreases hydrostatic pressure, causing
passive sugar diffusion. [INCORRECT]
Correct Answer: A
Rationale: At source tissues, active loading of sucrose into phloem decreases water
potential, causing water entry via osmosis and increasing turgor pressure; this pressure
drives sap to sinks where sugars are unloaded, completing the pressure-flow
mechanism. VERIFIED ✓ — Portage Learning BIOD 102 Module 2 Curriculum.
Q8: A student observes a plant with a distinct ring of vascular cambium producing
secondary xylem inwardly and secondary phloem outwardly. Over several years, the
central region of the stem becomes darker and non-functional. This central region is
termed:
A. Sapwood, which remains active in water transport. [INCORRECT]
B. Heartwood, consisting of older, non-living xylem that no longer conducts water but
provides structural support. [CORRECT]
C. Bark, which includes all tissues exterior to the vascular cambium. [INCORRECT]
D. Pith, the central ground tissue derived from the apical meristem. [INCORRECT]
Correct Answer: B
Rationale: Heartwood comprises older secondary xylem in which conducting cells have
become clogged with resins, tannins, and pigments, ceasing water transport but
providing durable mechanical support; sapwood remains the functional outer wood.
VERIFIED ✓ — Portage Learning BIOD 102 Module 2 Curriculum.
Q9: Which of the following is classified as an essential macronutrient required for plant
growth?
A. Iron, required in trace amounts for chlorophyll synthesis. [INCORRECT]
B. Zinc, necessary as a cofactor for enzyme activity in small quantities. [INCORRECT]
C. Nitrogen, a major component of amino acids, proteins, and nucleic acids required in
large quantities. [CORRECT]
D. Molybdenum, needed in minute amounts for nitrogen metabolism. [INCORRECT]
Correct Answer: C
Rationale: Macronutrients (N, P, K, Ca, Mg, S) are required in relatively large amounts for
plant structure and metabolism, whereas micronutrients (Fe, Mn, Zn, Cu, B, Mo, Cl, Ni)
are needed only in trace quantities. VERIFIED ✓ — Portage Learning BIOD 102 Module 2
Curriculum.
Biology II with Lab | Verified Q&A | Grade A |
Portage Learning | Pass Guaranteed - A+ Graded
SECTION 1: PLANT STRUCTURE & FUNCTION
Q1: Which vascular tissue is responsible for transporting water and dissolved minerals
from the roots to the aerial portions of the plant?
A. Phloem transports sugars and organic nutrients throughout the plant. [INCORRECT]
B. Xylem transports water and dissolved minerals from roots to shoots. [CORRECT]
C. The epidermis serves as the protective outer layer and does not conduct water.
[INCORRECT]
D. The cortex stores starch and facilitates radial transport but is not the primary
water-conducting tissue. [INCORRECT]
Correct Answer: B
Rationale: Xylem consists of tracheids and vessel elements that form hollow, lignified
tubes specialized for unidirectional water and mineral transport from roots to leaves via
transpiration pull. VERIFIED ✓ — Portage Learning BIOD 102 Module 2 Curriculum.
Q2: A botanist examines the root system of a mature oak tree and observes one large,
dominant vertical root with smaller lateral branches. This root system is classified as:
A. A fibrous root system composed of many thin, branching roots of similar diameter.
[INCORRECT]
B. A taproot system characterized by one large, dominant central root with lateral
branches. [CORRECT]
C. An adventitious root system arising from stems or leaves rather than the radicle.
[INCORRECT]
D. A prop root system that grows from the lower stem to provide structural support.
[INCORRECT]
Correct Answer: B
Rationale: Taproots feature a primary root that grows vertically downward and remains
dominant, with secondary roots branching laterally; this contrasts with fibrous systems
,where roots are roughly equal in size. VERIFIED ✓ — Portage Learning BIOD 102 Module
2 Curriculum.
Q3: In a cross-section of a dicot stem, vascular bundles are arranged in a distinct ring
pattern. How are vascular bundles typically arranged in a monocot stem?
A. In a ring pattern surrounding the pith, identical to dicot arrangement. [INCORRECT]
B. Scattered throughout the ground tissue without a defined ring. [CORRECT]
C. Concentrated only in the central pith region. [INCORRECT]
D. Arranged in a double ring with phloem interior and xylem exterior. [INCORRECT]
Correct Answer: B
Rationale: Monocot stems exhibit scattered vascular bundles embedded within the
ground tissue, whereas dicot stems organize vascular bundles in a distinct ring,
reflecting differences in vascular cambium activity and secondary growth capacity.
VERIFIED ✓ — Portage Learning BIOD 102 Module 2 Curriculum.
Q4: During a laboratory examination of a leaf cross-section, a student identifies the layer
of cells containing chloroplasts and responsible for most photosynthetic activity. This
layer is the:
A. Upper epidermis, which is transparent and lacks chloroplasts to allow light
penetration. [INCORRECT]
B. Palisade mesophyll, a columnar cell layer rich in chloroplasts and the primary site of
photosynthesis. [CORRECT]
C. Spongy mesophyll, which facilitates gas exchange but contains fewer chloroplasts
than the palisade layer. [INCORRECT]
D. Lower epidermis, which primarily houses stomata and guard cells for gas regulation.
[INCORRECT]
Correct Answer: B
Rationale: The palisade mesophyll consists of tightly packed, columnar parenchyma
cells containing the highest chloroplast density in the leaf, maximizing light capture for
photosynthesis. VERIFIED ✓ — Portage Learning BIOD 102 Module 2 Curriculum.
Q5: Which structural feature distinguishes primary growth from secondary growth in
woody plants?
A. Primary growth increases girth and diameter through lateral meristem activity.
[INCORRECT]
,B. Secondary growth increases length through apical meristem activity at root and
shoot tips. [INCORRECT]
C. Primary growth increases length through apical meristems, while secondary growth
increases girth through lateral meristems. [CORRECT]
D. Both primary and secondary growth occur exclusively at the tips of stems and roots.
[INCORRECT]
Correct Answer: C
Rationale: Primary growth is driven by apical meristems at root and shoot apices,
elongating the plant body, whereas secondary growth is driven by vascular and cork
cambiums (lateral meristems), adding woody tissue and increasing diameter. VERIFIED
✓ — Portage Learning BIOD 102 Module 2 Curriculum.
Q6: The cohesion-tension theory explains water movement in xylem primarily through
which mechanism?
A. Active transport of water molecules against their concentration gradient using ATP.
[INCORRECT]
B. Transpiration pull creating negative pressure, combined with hydrogen bonding
between water molecules and adhesion to xylem walls. [CORRECT]
C. Bulk flow driven by positive pressure generated in roots pushing water upward.
[INCORRECT]
D. Osmotic movement of water into phloem vessels at the source and out at the sink.
[INCORRECT]
Correct Answer: B
Rationale: Transpiration from leaf stomata creates negative pressure (tension) in xylem
vessels; water molecules cohere via hydrogen bonds and adhere to hydrophilic xylem
walls, enabling continuous upward movement without metabolic energy. VERIFIED ✓ —
Portage Learning BIOD 102 Module 2 Curriculum.
Q7: According to the pressure-flow hypothesis, translocation of sugars in phloem
occurs because:
A. Water potential gradients drive sugars from areas of high solute concentration
(sources) to low solute concentration (sinks) via bulk flow. [CORRECT]
B. Active transport of sucrose into xylem vessels creates a positive pressure gradient
that pushes water upward. [INCORRECT]
C. Transpiration pull generates negative pressure that draws sugars from leaves to
roots. [INCORRECT]
, D. Osmotic water movement into the source decreases hydrostatic pressure, causing
passive sugar diffusion. [INCORRECT]
Correct Answer: A
Rationale: At source tissues, active loading of sucrose into phloem decreases water
potential, causing water entry via osmosis and increasing turgor pressure; this pressure
drives sap to sinks where sugars are unloaded, completing the pressure-flow
mechanism. VERIFIED ✓ — Portage Learning BIOD 102 Module 2 Curriculum.
Q8: A student observes a plant with a distinct ring of vascular cambium producing
secondary xylem inwardly and secondary phloem outwardly. Over several years, the
central region of the stem becomes darker and non-functional. This central region is
termed:
A. Sapwood, which remains active in water transport. [INCORRECT]
B. Heartwood, consisting of older, non-living xylem that no longer conducts water but
provides structural support. [CORRECT]
C. Bark, which includes all tissues exterior to the vascular cambium. [INCORRECT]
D. Pith, the central ground tissue derived from the apical meristem. [INCORRECT]
Correct Answer: B
Rationale: Heartwood comprises older secondary xylem in which conducting cells have
become clogged with resins, tannins, and pigments, ceasing water transport but
providing durable mechanical support; sapwood remains the functional outer wood.
VERIFIED ✓ — Portage Learning BIOD 102 Module 2 Curriculum.
Q9: Which of the following is classified as an essential macronutrient required for plant
growth?
A. Iron, required in trace amounts for chlorophyll synthesis. [INCORRECT]
B. Zinc, necessary as a cofactor for enzyme activity in small quantities. [INCORRECT]
C. Nitrogen, a major component of amino acids, proteins, and nucleic acids required in
large quantities. [CORRECT]
D. Molybdenum, needed in minute amounts for nitrogen metabolism. [INCORRECT]
Correct Answer: C
Rationale: Macronutrients (N, P, K, Ca, Mg, S) are required in relatively large amounts for
plant structure and metabolism, whereas micronutrients (Fe, Mn, Zn, Cu, B, Mo, Cl, Ni)
are needed only in trace quantities. VERIFIED ✓ — Portage Learning BIOD 102 Module 2
Curriculum.
