Plant tissues — AQA GCSE Biology
Test yourself on Plant tissues with AQA GCSE practice questions.
7 days Premium · Then free forever · No card, no charge
Plant tissues explained
Plant tissues are groups of similar cells working together for a shared job, and each tissue's structure matches that job.
Read the full explanation
Epidermal tissue forms a thin, flat protective covering; its waxy cuticle reduces water loss. Palisade mesophyll is packed with chloroplasts and sits near the upper surface, so it absorbs light for photosynthesis. Spongy mesophyll has rounded cells with large air spaces, allowing carbon dioxide to diffuse to photosynthesising cells. Xylem contains dead, hollow, lignified cells that carry water and mineral ions upward and give support. Phloem contains living cells with sieve plates that translocate dissolved sugars. Meristem tissue at shoot and root tips divides to produce new growth. Explaining means linking each structural feature to the function it performs, not merely naming the tissue.
Plant tissues include: • epidermal tissues • palisade mesophyll • spongy mesophyll • xylem and phloem • meristem tissue found at the growing tips of shoots and roots.
A plant tissue is a group of similar cells adapted to carry out a particular function. Epidermal tissue covers plant surfaces and protects them; in leaves it also bears stomata and a waxy cuticle. Palisade mesophyll lies near the upper leaf surface and is packed with chloroplasts for photosynthesis. Spongy mesophyll has loosely arranged cells with air spaces that let gases diffuse through the leaf. Xylem transports water and mineral ions upward and supports the plant, while phloem translocates dissolved sugars. Meristem tissue is found at the growing tips of shoots and roots, where unspecialised cells divide to produce new growth. Recognising each tissue's location and role allows you to explain how a leaf or root carries out its functions.
The leaf is a plant organ. Knowledge limited to epidermis, palisade and spongy mesophyll, xylem and phloem, and guard cells surrounding stomata.
An organ is a group of tissues working together to carry out a function, and the leaf is the plant organ specialised for photosynthesis. Its upper and lower epidermis protect the leaf and reduce water loss through the waxy cuticle. Palisade mesophyll sits near the upper surface, where its many chloroplasts absorb light. Spongy mesophyll has air spaces that allow carbon dioxide to diffuse to the photosynthetic cells. Xylem delivers water and mineral ions, while phloem removes dissolved sugars. Guard cells surround stomata and change shape to open or close the pore, controlling gas exchange and water loss. Explaining the leaf as an organ means showing how these tissues cooperate, for example carbon dioxide entering through a stoma diffusing through spongy mesophyll to a palisade cell.
Your focus
- Identify the main plant tissues and state where each is found.
- Link at least one structural feature of each tissue to the function it performs.
- Use correct terminology such as cuticle, chloroplast, lignin, sieve plate and meristem when explaining adaptations.
Show all 9 objectives
- Name the main plant tissues listed in the specification.
- State the location and basic function of each named plant tissue.
- Distinguish transport tissues from photosynthetic and growth tissues.
- Explain why the leaf is classified as an organ.
- Describe the roles of the listed leaf tissues and guard cells.
- Relate the arrangement of leaf tissues to efficient photosynthesis and controlled gas exchange.
Plant tissues exam tips
Marking Points
- Epidermal tissue is a thin protective layer; in leaves it is covered by a waxy cuticle that reduces water loss by evaporation.
- Palisade mesophyll cells contain many chloroplasts and are positioned near the upper leaf surface, increasing light absorption for photosynthesis.
- Spongy mesophyll cells are loosely packed with air spaces between them, so carbon dioxide can diffuse quickly to palisade cells.
- Xylem tissue is made of dead, hollow cells strengthened with lignin; this allows water and mineral ions to move upward and provides support.
- Phloem tissue contains living cells with sieve plates; dissolved sugars are translocated from sources such as leaves to sinks such as roots and growing regions.
- Meristem tissue at the growing tips of shoots and roots contains cells that divide by mitosis, producing new cells for growth.
- Epidermal tissue forms a protective outer layer and, in leaves, secretes a waxy cuticle that limits water loss.
- Palisade mesophyll is a photosynthetic tissue containing many chloroplasts and positioned near the upper leaf surface.
- Spongy mesophyll contains loosely packed cells with air spaces that allow carbon dioxide and oxygen to diffuse within the leaf.
- Xylem is a transport tissue that carries water and mineral ions from the roots upward and provides structural support.
- Phloem is a transport tissue that translocates dissolved sugars from sources to sinks.
- Meristem tissue occurs at the growing tips of shoots and roots and contains cells that divide to produce new cells.
- The leaf is an organ because several tissues work together to carry out photosynthesis.
- Epidermal tissue protects the leaf and its waxy cuticle reduces water loss; stomata in the epidermis allow gases to enter and leave.
- Palisade mesophyll contains chloroplasts and is positioned near the upper surface to absorb light for photosynthesis.
- Spongy mesophyll has air spaces that allow carbon dioxide to diffuse through the leaf to the palisade cells.
- Xylem supplies water and mineral ions to leaf cells, and phloem transports dissolved sugars away from the leaf.
- Guard cells surround stomata and open or close the pore, balancing gas exchange with the need to limit water loss.
Examiner Tips
- 💡Use the connectives 'because' and 'so that' to turn each structural feature into a functional explanation.
- 💡When a question asks about a named tissue, refer to its location in the plant as well as its structure.
- 💡Check that every tissue named in the question has been addressed before finishing your answer.
- 💡Learn each tissue with its location and one key function so you can answer identification and explanation questions.
- 💡If asked to name tissues in a diagram, use the exact terms from the specification rather than everyday words.
- 💡For extended answers, group tissues by role, such as transport, photosynthesis and growth, to keep your response organised.
- 💡When explaining why the leaf is an organ, name at least two tissues and state how their functions combine.
- 💡Use the terms epidermis, palisade mesophyll, spongy mesophyll, xylem, phloem and guard cells accurately in labelled diagrams and written answers.
- 💡Link stomatal opening and closing to both gas exchange and water loss to show balanced understanding.
Common Mistakes
- Naming tissues without linking structure to function; the correction is to state the feature and then explain the job it enables, for example air spaces allow faster carbon dioxide diffusion.
- Claiming that xylem cells are living; the correction is that mature xylem cells are dead and hollow, which allows unimpeded water movement.
- Saying phloem carries water; the correction is that phloem translocates dissolved sugars, while xylem transports water and mineral ions.
- Confusing xylem and phloem; the correction is to remember that xylem carries water and mineral ions while phloem carries dissolved sugars.
- Placing meristem tissue throughout the whole plant; the correction is that it is found at the growing tips of shoots and roots.
- Describing spongy mesophyll as tightly packed; the correction is that its cells are loosely arranged with air spaces between them.
- Describing the leaf as a tissue; the correction is that the leaf is an organ made of several tissues working together.
- Saying stomata are cells; the correction is that stomata are pores, and the guard cells are the cells that surround and control each pore.
- Stating that guard cells only open stomata; the correction is that they can also close the pore to reduce water loss.