Biology Test Plant Biology 2 — Questions and Answers
Question 1: Which organelle is unique to plant cells and is responsible for photosynthesis?
- Mitochondria
- Chloroplast (Correct answer)
- Ribosome
- Lysosome
Correct answer: Chloroplast
Chloroplasts contain chlorophyll and are the sites of photosynthesis, converting light energy into chemical energy.
Question 2: What type of vascular tissue transports water and minerals from roots to leaves?
- Phloem
- Cortex
- Xylem (Correct answer)
- Epidermis
Correct answer: Xylem
Xylem transports water and dissolved minerals upward from roots through the stem to leaves.
Question 3: Which plant hormone is primarily responsible for fruit ripening?
- Auxin
- Gibberellin
- Cytokinin
- Ethylene (Correct answer)
Correct answer: Ethylene
Ethylene is a gaseous hormone that triggers fruit ripening, leaf abscission, and other senescence processes.
Question 4: What is the term for the movement of water across a semipermeable membrane from low to high solute concentration?
- Diffusion
- Active transport
- Osmosis (Correct answer)
- Facilitated diffusion
Correct answer: Osmosis
Osmosis is the passive movement of water molecules across a semipermeable membrane toward higher solute concentration.
Question 5: In C4 plants, where does initial CO2 fixation occur?
- Bundle sheath cells
- Guard cells
- Mesophyll cells (Correct answer)
- Epidermal cells
Correct answer: Mesophyll cells
In C4 plants, CO2 is initially fixed in mesophyll cells into a 4-carbon compound before being transferred to bundle sheath cells for the Calvin cycle.
Question 6: What structure regulates gas exchange in plant leaves?
- Trichomes
- Lenticels
- Stomata (Correct answer)
- Cuticle
Correct answer: Stomata
Stomata are pores in the leaf epidermis flanked by guard cells that open and close to regulate CO2 intake and water vapor loss.
Question 7: Which process describes the loss of water vapor from plant leaves?
- Transpiration (Correct answer)
- Respiration
- Guttation
- Translocation
Correct answer: Transpiration
Transpiration is the evaporation of water from plant surfaces, primarily through stomata, and drives the transpiration stream.
Biology Test Plant Biology 2
Which organelle is unique to plant cells and is responsible for photosynthesis?