Which mineral ion is involved in the opening and closing of stomata?
Calcium
Magnesium
Potassium
Iron
Related Questions
Certain plant species can thrive in soils with high concentrations of heavy metals like nickel. These plants often exhibit modified transport proteins. How might these modified proteins contribute to heavy metal tolerance?
By increasing the influx of nickel into the cytoplasm
By facilitating the efflux of essential nutrients to compensate for nickel toxicity
By converting nickel into less toxic forms
By sequestering nickel into vacuoles, reducing its cytoplasmic concentration
Iron deficiency in plants often leads to interveinal chlorosis. This is primarily due to the role of iron in:
Cell wall formation
Stomatal regulation
Synthesis of chlorophyll
Potassium uptake
What is the most efficient region of water absorption in roots?
Root cap
Growing point
Zone of elongation
Zone of differentiation
Which of the following is essential for the active uptake of mineral ions?
Water
Sunlight
ATP
Carbon dioxide
Unlike facilitated diffusion, active transport:
Does not require energy
Occurs down a concentration gradient
Uses protein channels
Requires energy
A researcher is studying the uptake of iron (Fe) by plant roots. They observe that the process is significantly inhibited by the presence of respiratory inhibitors. Which of the following best explains this observation?
Iron uptake is a passive process driven by diffusion.
Iron uptake is facilitated by anaerobic respiration.
Iron uptake is coupled with the release of oxygen.
Iron uptake is an active process requiring energy from respiration.
Which of the following is NOT a factor affecting the uptake of mineral ions by plants?
Soil pH
Concentration of mineral ions in the soil
Presence of chlorophyll
Root hair density
Which of the following is NOT a mechanism by which mycorrhizae enhance mineral uptake in plants?
Increasing the surface area for absorption
Producing chelating agents that solubilize minerals
Directly converting atmospheric nitrogen into usable forms for the plant
Improving the plant's access to phosphorus
Researchers observed that a specific plant species accumulates high levels of cadmium (Cd) in its tissues, even when grown in soil with relatively low Cd concentrations. Which transport mechanism is MOST likely responsible for this observation?
Passive diffusion across the cell membrane
Facilitated diffusion through non-specific channels
Active transport through Cd-specific transporters with high affinity
Endocytosis of Cd-containing soil particles
The process by which plants accumulate mineral ions against their concentration gradient, requiring energy, is called:
Passive transport
Diffusion
Osmosis
Active transport
