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Plants, leaves & photosynthesis
Explore how roots, stems, leaves and flowers support plant growth and photosynthesis. Review suitability for your learners before teaching.
Worksheet StudioPractice pack · Ages 10-12
Plants, leaves & photosynthesis
Take your time. Show your thinking.
1. What sugar do plants produce during photosynthesis to use for energy and growth (or store as starch): glucose or lactose?
2. In which main plant organ does most photosynthesis take place: the leaves or the roots?
3. What chemical reagent turns blue-black when added to a leaf that contains stored starch: iodine solution or pure water?
4. Which three conditions do most seeds need to germinate: water, oxygen and warmth, or darkness, ice and salt?
5. What is the role of the green sepals on the outside of a flower bud: to protect the unopened flower bud, or to absorb soil nitrates?
6. Which gas do plants release as a byproduct of photosynthesis: oxygen or helium?
7. After fertilisation, which part of a flowering plant develops into a fruit enclosing the seeds: the ovary or the sepal?
8. Why do plants need nitrate ions from the soil: to make amino acids and proteins for cell growth, or to freeze water?
9. Why do many insect-pollinated flowers have brightly coloured petals and sweet nectar: to attract pollinators, or to absorb soil water?
10. Why do plants need magnesium ions from the soil: to make green chlorophyll, or to attract wind?
11. In which cell organelles inside palisade leaf cells does photosynthesis occur: chloroplasts or ribosomes?
12. Which gas do plants take in from the air through tiny pores (stomata) to use in photosynthesis: carbon dioxide or nitrogen?
12 questions · Seed 44 · Age guidance, not curriculum certification
View the answer key
Worksheet StudioAnswer key · Ages 10-12
Plants, leaves & photosynthesis
Answers and reasoning. Review before teaching.
1. What sugar do plants produce during photosynthesis to use for energy and growth (or store as starch): glucose or lactose?
GlucosePhotosynthesis synthesises glucose (C₆H₁₂O₆), which plants use in respiration or convert to starch and cellulose.
2. In which main plant organ does most photosynthesis take place: the leaves or the roots?
LeavesBroad green leaves capture sunlight and carbon dioxide for photosynthesis.
3. What chemical reagent turns blue-black when added to a leaf that contains stored starch: iodine solution or pure water?
Iodine solutionYellow-brown iodine solution turns blue-black in the presence of starch.
4. Which three conditions do most seeds need to germinate: water, oxygen and warmth, or darkness, ice and salt?
Water, oxygen and warmthSeeds require water to activate enzymes, oxygen for respiration, and suitable warmth.
5. What is the role of the green sepals on the outside of a flower bud: to protect the unopened flower bud, or to absorb soil nitrates?
To protect the unopened flower budSepals enclose and protect the developing petals before the flower opens.
6. Which gas do plants release as a byproduct of photosynthesis: oxygen or helium?
OxygenOxygen produced during photosynthesis diffuses out of the leaves into the air.
7. After fertilisation, which part of a flowering plant develops into a fruit enclosing the seeds: the ovary or the sepal?
OvaryThe fertilised ovules become seeds while the surrounding ovary wall ripens into a fruit.
8. Why do plants need nitrate ions from the soil: to make amino acids and proteins for cell growth, or to freeze water?
To make amino acids and proteins for cell growthPlants combine glucose with nitrogen from nitrates to synthesise amino acids and proteins.
9. Why do many insect-pollinated flowers have brightly coloured petals and sweet nectar: to attract pollinators, or to absorb soil water?
To attract pollinatorsBees and butterflies visit for nectar and carry pollen between flowers.
10. Why do plants need magnesium ions from the soil: to make green chlorophyll, or to attract wind?
To make green chlorophyllMagnesium is the central atom in every chlorophyll molecule; deficiency causes yellow leaves (chlorosis).
11. In which cell organelles inside palisade leaf cells does photosynthesis occur: chloroplasts or ribosomes?
ChloroplastsChloroplasts contain chlorophyll and the enzymes needed for photosynthesis.
12. Which gas do plants take in from the air through tiny pores (stomata) to use in photosynthesis: carbon dioxide or nitrogen?
Carbon dioxidePlants combine carbon dioxide and water using light energy to make glucose and oxygen.
12 questions · Seed 44 · Age guidance, not curriculum certification
Worksheet StudioPractice pack · Ages 10-12
Plants, leaves & photosynthesis
Take your time. Show your thinking.
1. What sugar do plants produce during photosynthesis to use for energy and growth (or store as starch): glucose or lactose?
2. In which main plant organ does most photosynthesis take place: the leaves or the roots?
3. What chemical reagent turns blue-black when added to a leaf that contains stored starch: iodine solution or pure water?
4. Which three conditions do most seeds need to germinate: water, oxygen and warmth, or darkness, ice and salt?
5. What is the role of the green sepals on the outside of a flower bud: to protect the unopened flower bud, or to absorb soil nitrates?
6. Which gas do plants release as a byproduct of photosynthesis: oxygen or helium?
7. After fertilisation, which part of a flowering plant develops into a fruit enclosing the seeds: the ovary or the sepal?
8. Why do plants need nitrate ions from the soil: to make amino acids and proteins for cell growth, or to freeze water?
9. Why do many insect-pollinated flowers have brightly coloured petals and sweet nectar: to attract pollinators, or to absorb soil water?
10. Why do plants need magnesium ions from the soil: to make green chlorophyll, or to attract wind?
11. In which cell organelles inside palisade leaf cells does photosynthesis occur: chloroplasts or ribosomes?
12. Which gas do plants take in from the air through tiny pores (stomata) to use in photosynthesis: carbon dioxide or nitrogen?
12 questions · Seed 44 · Age guidance, not curriculum certification
Worksheet StudioAnswer key · Ages 10-12
Plants, leaves & photosynthesis
Answers and reasoning. Review before teaching.
1. What sugar do plants produce during photosynthesis to use for energy and growth (or store as starch): glucose or lactose?
GlucosePhotosynthesis synthesises glucose (C₆H₁₂O₆), which plants use in respiration or convert to starch and cellulose.
2. In which main plant organ does most photosynthesis take place: the leaves or the roots?
LeavesBroad green leaves capture sunlight and carbon dioxide for photosynthesis.
3. What chemical reagent turns blue-black when added to a leaf that contains stored starch: iodine solution or pure water?
Iodine solutionYellow-brown iodine solution turns blue-black in the presence of starch.
4. Which three conditions do most seeds need to germinate: water, oxygen and warmth, or darkness, ice and salt?
Water, oxygen and warmthSeeds require water to activate enzymes, oxygen for respiration, and suitable warmth.
5. What is the role of the green sepals on the outside of a flower bud: to protect the unopened flower bud, or to absorb soil nitrates?
To protect the unopened flower budSepals enclose and protect the developing petals before the flower opens.
6. Which gas do plants release as a byproduct of photosynthesis: oxygen or helium?
OxygenOxygen produced during photosynthesis diffuses out of the leaves into the air.
7. After fertilisation, which part of a flowering plant develops into a fruit enclosing the seeds: the ovary or the sepal?
OvaryThe fertilised ovules become seeds while the surrounding ovary wall ripens into a fruit.
8. Why do plants need nitrate ions from the soil: to make amino acids and proteins for cell growth, or to freeze water?
To make amino acids and proteins for cell growthPlants combine glucose with nitrogen from nitrates to synthesise amino acids and proteins.
9. Why do many insect-pollinated flowers have brightly coloured petals and sweet nectar: to attract pollinators, or to absorb soil water?
To attract pollinatorsBees and butterflies visit for nectar and carry pollen between flowers.
10. Why do plants need magnesium ions from the soil: to make green chlorophyll, or to attract wind?
To make green chlorophyllMagnesium is the central atom in every chlorophyll molecule; deficiency causes yellow leaves (chlorosis).
11. In which cell organelles inside palisade leaf cells does photosynthesis occur: chloroplasts or ribosomes?
ChloroplastsChloroplasts contain chlorophyll and the enzymes needed for photosynthesis.
12. Which gas do plants take in from the air through tiny pores (stomata) to use in photosynthesis: carbon dioxide or nitrogen?
Carbon dioxidePlants combine carbon dioxide and water using light energy to make glucose and oxygen.
12 questions · Seed 44 · Age guidance, not curriculum certification