Plant Physiology Quiz – 1st Year Biology | Chapter 8 Study Tool
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Total Marks: 50
Time: 60 min
Questions: 25

Biology (SNC) – 1st Year

Chapter: #8 – Plant Physiology
Subject: Biology
Level: 1st Year Science
Type: Practice Quiz
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Chapter 8: Plant Physiology

Multiple Choice Questions (10×1=10)

1
Which of the following is not a function of xylem?
A Transport of water
B Transport of minerals
C Transport of food
D Mechanical support
2
Plants that are adapted to survive in dry conditions:
A Xerophytes
B Hydrophytes
C Mesophytes
D Halophytes
3
Guard cells are characterized by ……
A Being bean-shaped
B Being square-shaped
C Lacking nuclei and mitochondria
D Being present only in roots and containing chloroplasts and lacking chloroplasts and mitochondria
4
…… cells of phloem are responsible for transporting sugars.
A Phloem fibers
B Phloem parenchyma
C Sieve tube elements
D Guard cells
5
…… type of meristem is responsible for the increase in length of roots and shoots.
A Lateral meristem
B Cork cambium
C Intercalary meristem
D Apical meristem
6
Primary growth in plant occurs due to ……
A Apical meristem
B Cork cambium
C Vascular cambium
D Lateral meristem
7
How do cold region plants like oaks and maples avoid cell damage from freezing?
A By altering solute
B By increasing water content in cell
C By shedding all leaves in winter
D By producing heat shock proteins in excess formation
8
Negative geotropism is observed in ……
A Roots growing upward
B Leaves folding at night
C Shoots growing upward
D Vines coiling around supports
9
Short day plants flower when ……
A Nights are longer than a critical length
B Nights are shorter than a critical length
C Day are longer than nights
D Light intensity is high
10
What is the approximate effective temperature range for vernalisation?
A 0°C to 4°C
B 10°C to 15°C
C 20°C to 25°C
D 30°C to 35°C

Short Answer Questions (15×2=30)

Detailed Answer Questions (Answer any 2) (2×5=10)

1. Describe osmoregulation in Hydrophytes and Halophytes.

Plant Adaptations Comparison:
Hydrophytes (Aquatic Plants):
• Thin cuticle or no cuticle
• Large air spaces (aerenchyma)
• Reduced vascular tissue
• Floating leaves with stomata on upper surface

Halophytes (Salt-tolerant Plants):
• Salt glands to excrete excess salt
• Succulent tissues for water storage
• Accumulate compatible solutes (proline, glycine betaine)
• Reduced leaf area to minimize transpiration

2. Analyze the daily cycle of stomatal opening and closing in plants. Why is this rhythm crucial for plant survival and how does it balance the competing need of CO₂ uptake for photosynthesis versus water conservation through transpiration?

Stomatal Regulation:
Daytime (Light):
• Photosynthesis active → CO₂ needed
• Guard cells swell with K⁺ and water
• Stomata open → CO₂ enters, O₂ exits
• Transpiration occurs → Water lost

Nighttime (Dark):
• Photosynthesis stops → Less CO₂ needed
• Guard cells lose K⁺ and water
• Stomata close → Water conserved
• Respiration continues with stored O₂

3. Explain the role of source and sink in phloem translocation providing examples of each.

Source-Sink Relationship:
Source (Sugar Production):
• Mature leaves (photosynthesis)
• Storage organs (tubers, bulbs)
• Sugar loaded into phloem
• Creates high osmotic pressure

Sink (Sugar Consumption):
• Growing roots and shoots
• Developing fruits and seeds
• Storage tissues (when accumulating)
• Sugar unloaded from phloem
Plant Vascular Tissues:
Xylem: Water & Minerals ↑ Phloem: Sugars ↕ (Source to Sink)