Science Group
Explore subjects and practice MCQs
7
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Total MCQs
Science Group
Answer: Phloem carries organic food by translocation from leaves to other plant parts.
Answer: Sieve tubes are living phloem cells that conduct sugars and other organic food.
Answer: Guttation occurs through hydathodes, which are special pores found at leaf margins.
Answer: When transpiration is low and root pressure is high, water is forced out as droplets through hydathodes.
Answer: Cohesive forces hold water molecules together, keeping the xylem water column continuous.
Answer: Lenticels are pores on woody stems and some roots that allow gaseous exchange.
Answer: The three types of transpiration are stomatal, cuticular and lenticular; xylary transpiration does not exist.
Answer: Stomatal transpiration accounts for roughly 90% of the water lost by a plant.
Answer: Photosynthesis combines carbon dioxide and water to make glucose while releasing oxygen.
Answer: Low humidity, high temperature, wind and light all increase the rate of transpiration.
Answer: Root pressure pushes water up the xylem and is a major cause of guttation.
Answer: Mineral ions are usually taken up actively, using energy, against the concentration gradient.
Answer: Respiration breaks down glucose and releases carbon dioxide, water and energy.
Answer: Diffusion is the passive movement of molecules from higher to lower concentration.
Answer: Active transport uses metabolic energy (ATP) to move substances against the concentration gradient.
Answer: The conducting cells of xylem are dead and hollow, forming continuous tubes for water flow.
Answer: Food transport is carried out by the phloem, not by transpiration.
Answer: Translocation is the movement of organic food through the phloem from source to sink.
Answer: Leaves that make food act as the source, while storage and growing parts act as sinks.
Answer: The external hypertonic solution draws water out of the cell by osmosis, causing plasmolysis.