A free printable leaf structure and plant function worksheet for Grade 11 biology.
This free leaf structure worksheet shows how a leaf is built to make food and move water. Students label ten parts of a drawn leaf cross-section, from the waxy cuticle to the guard cells, and match each structure to its job.
They then apply what they know: photosynthesis, a potometer experiment on transpiration, counting stomata under a drawn microscope field to calculate stomatal density, and the effects of plant hormones. The transpiration rates and stomatal density in the key were calculated and checked.
| Part | Skill practised | Marks |
|---|---|---|
| A | Label a leaf cross-section (10 parts) | 5 |
| B | Match structures to functions | 3 |
| C | Photosynthesis and leaf adaptations | 3 |
| D | Transpiration data and water transport | 6 |
| E | Counting stomata and stomatal density | 2 |
| F | Plant hormones | 2 |
| G | Spot the mistake | 2 |
It supports the Ontario Grade 11 biology curriculum expectations in the Plants: Anatomy, Growth and Function unit.
A leaf is only a few cells thick, but every layer has a job. This is the diagram from Part A of the leaf structure worksheet:
The tightly packed palisade mesophyll does most of the photosynthesis, while the loose spongy mesophyll and its air spaces let gases move through the leaf. Gases enter and leave through stomata, each opened and closed by a pair of guard cells. For more detail, see the leaf on Wikipedia.
| Structure | Function |
|---|---|
| Palisade mesophyll | Tightly packed cells with many chloroplasts where most photosynthesis happens |
| Spongy mesophyll | Loosely packed cells with air spaces that let gases diffuse through the leaf |
| Stomata | Openings that let CO₂ in and O₂ and water vapour out |
| Guard cells | Swell or shrink to open and close each stoma |
| Xylem | Carries water and minerals up from the roots |
| Phloem | Carries sugars from the leaves to the rest of the plant |
Students match these in Part B of the leaf structure worksheet. Photosynthesis itself, carbon dioxide + water → glucose + oxygen, is covered in Part C.
Water evaporating from the leaf through the stomata pulls a continuous column of water up the xylem. Water molecules stick together (cohesion), so the pull reaches all the way to the roots. In Part D, a potometer measures water uptake under four conditions:
| Condition | Water taken up in 30 min (mL) | Rate (mL/h) |
|---|---|---|
| Normal room conditions | 1.2 | 2.4 |
| Fan blowing on the plant | 2.1 | 4.2 |
| In the dark | 0.4 | 0.8 |
| Clear plastic bag over the plant | 0.5 | 1.0 |
Wind removes humid air from around the leaf and speeds transpiration; darkness closes the stomata and slows it. Moving water through a plant has a lot in common with moving blood through the body, which the circulatory system worksheet covers.
In Part E, students count the stomata in a microscope field of view and calculate the stomatal density. With 14 stomata in a circle 0.40 mm across, the area is π × 0.20² = 0.126 mm², so the density is about 111 stomata per mm².
The same method works in a real lab: paint clear nail polish on the underside of a leaf, peel it off with tape and count the stomata in the imprint.
These questions match the leaf structure worksheet PDF, which has the full-size diagrams, word bank and ruled answer space.
Questions 1–10: label the ten numbered parts of the leaf cross-section above.
Questions 11–16: match each structure to its function.
Questions 26–29: match auxin, gibberellin, ethylene and abscisic acid to their effects.
Open each part of the leaf structure worksheet answers to check your work. The printable key is at the end of the PDF.
Review with the photosynthesis quiz, and see how plants and animals use the glucose with the cellular respiration quiz.
Yes. The worksheet and its answer key are free to download and print as a PDF, with no account needed.
Cuticle, upper epidermis, palisade mesophyll, spongy mesophyll, lower epidermis (with stomata and guard cells), and a lower cuticle. Veins containing xylem and phloem run through the mesophyll.
It sits just under the upper surface, where light is strongest, so packing chloroplasts there makes photosynthesis as efficient as possible.
Xylem carries water and dissolved minerals up from the roots. Phloem carries sugars made in the leaves to growing parts and storage organs.
Wind, light, heat and low humidity all increase transpiration. Darkness and humid air slow it down.
Ready to start? Download the free leaf structure worksheet PDF (use the Download button above), print it double-sided, and keep the answer key pages for marking.