Plant Nutrition
Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.
Photosynthesis
SubtopicPhotosynthesis under Plant Nutrition for Grade 12 IGCSE.
Preview questions (no answers)
- 1.
Why do aquatic plants, like Elodea, produce bubbles when placed in bright light?
A.They are releasing carbon dioxide
B.They are releasing oxygen gas
C.They are absorbing nitrogen
D.The water is boiling
- 2.
Which of the following is the correct word equation for photosynthesis?
A.Glucose + Oxygen -> Carbon Dioxide + Water
B.Carbon Dioxide + Oxygen -> Glucose + Water
C.Carbon Dioxide + Water -> Glucose + Oxygen
D.Glucose + Water -> Carbon Dioxide + Oxygen
- 3.
When testing a leaf for starch, why is a water bath used to heat the ethanol?
A.To keep the ethanol at exactly
B.Because ethanol is highly flammable
C.To prevent the leaf from dissolving
D.To speed up the reaction with iodine
- 4.
What does a 'limiting factor' mean in the context of photosynthesis?
A.The factor that is in excess
B.The factor that is at its optimum
C.The factor that is in shortest supply and restricts the rate
D.The factor that the plant does not need
- 5.
If the rate of photosynthesis is measured by the volume of oxygen produced per minute, why might this be an 'underestimate' of the actual rate?
A.Some oxygen is used up by the plant for aerobic respiration
B.Some oxygen dissolves into the surrounding water
C.The bubbles may contain nitrogen as well as oxygen
D.Photosynthesis also produces carbon dioxide which cancels out the oxygen
- 6.
Which of the following correctly pairs a leaf adaptation with its benefit?
A.Thin leaf - Reduces the distance for gas diffusion
B.Thick cuticle - Increases light absorption
C.Many stomata on the upper surface - Reduces water loss
D.Air spaces in spongy mesophyll - Increases structural rigidity
- 7.
In the experiment to show that is necessary for photosynthesis, what substance is used to absorb from the air in a sealed bell jar?
A.Sodium hydrogencarbonate
B.Potassium hydroxide (or Soda Lime)
C.Distilled water
D.Calcium carbonate
- 8.
In the reduction step of the Calvin cycle, what happens to the Glycerate-3-phosphate (GP)?
A.It is oxidized by NADPH and phosphorylated by ATP.
B.It is reduced by NADPH and phosphorylated by ATP.
C.It is carboxylated by Rubisco.
D.It is converted into RuBP using 2 molecules of ATP.
- 9.
If a plant is under severe water stress, why does the rate of photosynthesis decrease even if light intensity is high?
A.The stomata close to prevent transpiration, which limits the supply.
B.Water is no longer available to be used as a pigment.
C.The plant uses instead of for photolysis.
D.The chloroplasts migrate to the center of the cell where there is no light.
- 10.
What is the primary role of the thylakoid membrane structure in ATP synthesis?
A.It provides a large surface area for Rubisco to bind.
B.It acts as an impermeable barrier to maintain a proton gradient.
C.It contains pores that allow glucose to exit the chloroplast.
D.It absorbs and stores it for the Calvin cycle.
Download the worksheet for Plant Nutrition - Photosynthesis to practice offline. It includes additional chapter-level practice questions.
Leaf structure
SubtopicLeaf structure under Plant Nutrition for Grade 12 IGCSE.
Preview questions (no answers)
- 1.
Why is a leaf classified as an organ in a plant?
A.It is made of only one type of cell
B.It is part of the root system
C.It is made of several different tissues working together
D.It can move from one place to another
- 2.
Which mesophyll layer is located further away from the top surface of the leaf?
A.Palisade mesophyll
B.Spongy mesophyll
C.Upper epidermis
D.Vascular bundle
- 3.
How does the waxy cuticle interact with sunlight?
A.It reflects all light
B.It absorbs all light
C.It allows light to pass through
D.It turns light into sugar
- 4.
Which mineral ion is essential for the leaf to produce chlorophyll?
A.Calcium
B.Magnesium
C.Potassium
D.Sodium
- 5.
Which of the following is the best description of the leaf as an organ?
A.A collection of similar cells performing one function
B.A group of different tissues working together to carry out photosynthesis
C.A part of the plant that only functions during the day
D.A structure made entirely of mesophyll cells
- 6.
If a leaf is deprived of light for 48 hours, what would you expect to happen to its starch levels?
A.Starch levels would increase as the plant saves energy
B.Starch levels would stay the same
C.Starch would be converted back to sucrose and transported away
D.Starch would be converted into cellulose for growth
- 7.
How do guard cells differ structurally from other epidermal cells regarding their cell walls?
A.They have uniformly thin walls
B.They have walls that are thicker on the side adjacent to the pore
C.They have walls made of lignin rather than cellulose
D.They have no cell walls
- 8.
In the leaf of a xerophyte, the 'multiseriate' (multiple-layered) epidermis serves what primary structural function?
A.Increasing the rate of photosynthesis by adding more chloroplast-containing cells
B.Acting as a water storage tissue and an extra barrier to prevent water loss
C.Providing a site for the accumulation of excess salts
D.Allowing for the leaf to rapidly change its shape in response to light
- 9.
The 'index of stomatal frequency' is the percentage of epidermal cells that are stomata. If two leaves have the same stomatal density but different indices, what must be true?
A.The leaf with the higher index has smaller epidermal cells
B.The leaf with the lower index has more trichomes
C.The leaf with the higher index has a thicker cuticle
D.The leaf with the lower index is from a C4 plant
- 10.
Why are 'vein endings' in the leaf mesophyll usually surrounded by a high density of tracheids rather than vessels?
A.Tracheids are better at filtering out pathogens before they reach the mesophyll
B.Tracheids provide a larger surface-area-to-volume ratio for the unloading of water into the apoplast
C.Vessels are too wide to fit into the small spaces between mesophyll cells
D.Tracheids are the only type of xylem tissue that can remain alive at maturity
Download the worksheet for Plant Nutrition - Leaf structure to practice offline. It includes additional chapter-level practice questions.
Mineral requirements
SubtopicMineral requirements under Plant Nutrition for Grade 12 IGCSE.
Preview questions (no answers)
- 1.
What is the primary function of mineral ions in plants?
A.To provide a source of energy
B.To serve as building blocks and maintain metabolic processes
C.To provide structural support to the cell wall only
D.To increase the temperature of the plant
- 2.
Mineral ions are transported around the plant in which tissue?
A.Xylem
B.Phloem
C.Epidermis
D.Cortex
- 3.
A plant with very small, pale leaves and a thin stem is likely lacking in:
A.Nitrogen
B.Magnesium
C.Iron
D.Potassium
- 4.
Which element is needed to produce amino acids, which are then used to make proteins?
A.Nitrogen
B.Magnesium
C.Carbon
D.Oxygen
- 5.
Which molecule in the plant contains both nitrogen and phosphorus?
A.Glucose
B.DNA
C.Chlorophyll
D.Cellulose
- 6.
Why is the uptake of minerals by a plant considered a selective process?
A.Because only certain minerals can dissolve in water
B.Because specific carrier proteins in the cell membrane only move certain ions
C.Because the plant only takes up minerals when it is sunny
D.Because minerals are only absorbed by the flowers
- 7.
A plant leaf shows 'burnt' edges and curling. This is often a sign of deficiency in which ion that regulates water balance?
A.Magnesium
B.Nitrate
C.Potassium
D.Phosphate
- 8.
Which of the following is a role of Silicon () in plants, particularly in grasses and horsetails?
A.It is a component of the chlorophyll molecule.
B.It is deposited in cell walls as silica to provide structural strength and defense against herbivores.
C.It is the main enzyme for the fixation of .
D.It is used to store genetic information instead of phosphorus.
- 9.
What happens to the rate of active mineral uptake if the soil temperature drops significantly?
A.It increases because the minerals are more stable at low temperatures.
B.It decreases because the kinetic energy of molecules is lower and membrane fluidity is reduced, slowing down carrier proteins.
C.It stays the same because active transport is independent of temperature.
D.It increases because the plant needs more minerals to generate heat.
- 10.
A plant experiencing 'Blossom End Rot' in its fruits is likely deficient in which nutrient, often due to irregular watering rather than a lack of the nutrient in the soil?
A.Nitrogen
B.Calcium
C.Potassium
D.Phosphorus
Download the worksheet for Plant Nutrition - Mineral requirements to practice offline. It includes additional chapter-level practice questions.