ScienceCBSE Class 9 · Tissues in Action

Plant Tissues: Meristems, Simple and Complex Permanent Tissues (Class 9)

Updated 17 October 2026 · Fact-checked

Plant tissues are meristematic (cells that keep dividing: apical for length, lateral for girth, intercalary for regrowth) or permanent (differentiated cells that no longer divide). Simple permanent tissues are parenchyma (storage, living, thin wall), collenchyma (flexible support, corners thickened with pectin) and sclerenchyma (strength, dead, lignified). Complex tissues are xylem (water and minerals upward) and phloem (food from leaves), and tissues form three systems: dermal, ground and vascular.

Notice that apical meristems sit at the tips for length, intercalary above nodes for regrowth, and the lateral ring between bark and wood adds girth.

Illustration drawn for QuestionBuddy.

Understand Plant Tissues: Meristematic and Permanent

Levels and division of labour. A tissue is a team of similar cells doing one job. In many-celled organisms the order is cell, tissue, organ, organ system, organism. In a one-celled organism such as Amoeba one cell does everything; in plants and animals different groups of cells take on different jobs (division of labour). Plant tissues differ from animal tissues because plants are fixed in one place, need rigid support, make their own food by photosynthesis and keep growing in certain regions.

Meristematic tissue. Plants grow in length, in girth and by regrowth after cutting or grazing; all need cells that keep dividing, called meristematic tissue. Apical meristem lies at the tips of root and shoot and increases length. Lateral meristem is a ring along the circumference of the stem and increases girth, making annual rings in trees. Intercalary meristem lies at the base of internodes or just above the nodes (in grasses) and gives regrowth after mowing or grazing. Meristematic cells are small, with thin walls, a large nucleus, dense cytoplasm, no vacuoles (or very small ones) and no intercellular spaces, all of which suit fast division. Annual rings: lateral meristem adds a new layer of wood each year; wide rings mean good years and narrow rings mean poor years; counting rings gives the age of the tree.

Permanent tissue. Cells made by meristem that lose the power to divide and change shape and contents for one job undergo differentiation, giving permanent tissue. Simple permanent tissue has one type of cell (parenchyma, collenchyma, sclerenchyma); complex permanent tissue has more than one cell type working as a unit (xylem, phloem).

Epidermis (protective tissue). The outermost single layer of flat, tightly packed cells, covered by a waxy cuticle (cutin) that reduces water loss and keeps out parasites (thick in desert plants). Root hairs are outgrowths of root epidermal cells that give a large surface for absorbing water and minerals. The leaf epidermis has stomata for gas exchange and transpiration, which creates a pull that draws water up the xylem. In older trees a cork cambium makes dead, waterproof cork cells, the bark.

Simple permanent tissues. Parenchyma: living cells, thin walls, many intercellular spaces; stores food, photosynthesis in green parts, air spaces in water plants. Collenchyma: living, walls thickened unevenly at the corners with pectin, few spaces; gives support with flexibility (leaf stalks, young stems, tendrils). Sclerenchyma: mostly dead, walls thick all round with lignin, almost no spaces; gives strength and hardness (seed coats, coconut husk, walnut shell).

Complex permanent tissues. Xylem carries water and minerals upwards from roots and gives strength; it has tracheids and vessels (dead, thick-walled), xylem parenchyma (the only living part) and xylem fibres. Phloem carries food (sugars) from the leaves up or down; it has sieve tubes joined through sieve plates, companion cells that control sieve tubes, phloem parenchyma and phloem fibres (the only dead part). Tissue systems: dermal (epidermis, later bark), ground (parenchyma, collenchyma, sclerenchyma) and vascular (xylem and phloem).

Totipotency. In 1958 F. C. Steward grew a whole carrot plant from single phloem cells in a nutrient medium; the cells lost their specialisation, divided, then differentiated again into root and shoot. This is the basis of plant tissue culture.

Plant Tissues: Meristematic and Permanent: formulas and key facts

Levels of organisation: 1.Cell
2.tissue
3.organ
4.organ system
5.organism
Meristems: Apical length
lateral girth and annual rings
intercalary regrowth
Simple permanent tissues: Parenchyma living, thin, storage
collenchyma living, pectin corners, flexible
sclerenchyma dead, lignin, strong
Complex tissues: Xylem: water and minerals up | phloem: food from leaves
Tissue systems: $D er ma l ∣ g r o u n d ∣ v a sc u l a r$
Rate and growth: $R a t e = d i s t an ce \div t im e ∣ a g eo f a t r ee = n u mb er o f ann u a l r in g s$

Apical	length
lateral	girth and annual rings
intercalary	regrowth

Parenchyma	living, thin, storage
collenchyma	living, pectin corners, flexible
sclerenchyma	dead, lignin, strong

How to solve Plant Tissues: Meristematic and Permanent questions

Use this method for plant tissue identification and data questions.

1Ask whether the cells divide (meristem) or not (permanent), and where the tissue is.
2For permanent tissue, check whether the cells are living or dead, the wall thickness and the job.
3Match structure to function: thin walls with air spaces for storage; pectin corners for flexible support; lignin for strength.
4For xylem and phloem, name the direction and the material carried, and which cells are living.
5For ring or rate data, compute totals, means and rates with units (mm, cm per hour).
6Write the answer with a named example of where the tissue is found.

Plant Tissues: Meristematic and Permanent in real life

Each concept, met in an everyday situation. Read the situation, try the problem, then check the solution. The one-line hook is what to remember.

Why a lawn grows back after mowing

Suppose a gardener mows a lawn to a grass height of 3 cm and notes that the blades grow back by 1.5 cm every day.

Name the tissue responsible and find the time to regrow to 12 cm.

Try it first, then show the solutionSolution

Grasses have intercalary meristem at the base of the blades (above the nodes), which keeps dividing after the tip is cut.
Growth needed = 12 − 3 = 9 cm; time = 9 ÷ 1.5 = 6 days.

Answer: Intercalary meristem; 6 days.

Memory hook: Cut the tip, the base keeps growing.

Why a fresh twig bends but a dry coconut husk fibre does not

Suppose a student bends a fresh green twig and a hard coconut husk fibre, and the twig bends while the fibre resists.

Name the tissues and explain the difference.

Try it first, then show the solutionSolution

The fresh twig has collenchyma, whose living cells have walls thickened at the corners with pectin, which acts like rubber and lets the stem bend.
The husk fibre is sclerenchyma: dead cells with thick, lignified walls all round, giving strength and hardness.
Lignin makes the walls hard and waterproof, so the fibre resists bending.

Answer: Collenchyma (flexible) and sclerenchyma (hard).

Memory hook: Pectin bends, lignin stiffens.

Tricks to remember Plant Tissues: Meristematic and Permanent

Short memory aids. Say each one aloud once, then use it on a question the same day.

Apical, Lateral, Intercalary: tip, side, base
Apical at the tip (length), lateral at the side (girth), intercalary at the base of the node (regrowth).
Use it when: Naming meristems and their jobs.
P-C-S: Soft, Flexible, Strong
Parenchyma stores, Collenchyma bends, Sclerenchyma is strong.
Use it when: Simple permanent tissues.
Xylem up water, phloem food around
Xylem: X for 'eXtra water up'. Phloem: P for 'plant food' from leaves.
Use it when: Direction and material carried.
Only part is alive
In xylem only parenchyma is living; in phloem only fibres are dead.
Use it when: Living versus dead cells.

Plant Tissues: Meristematic and Permanent: solved examples

Ordered from board level to HOTS. Try each one before you open the solution.

Example 1: The three meristems · 3 marks · Short answerBoard level

Name the three types of meristem, state where each occurs and what each does, and give two features of meristematic cells.

Try it first, then show the solutionSolution

Apical: at tips of root and shoot, increases length. Lateral: ring along the stem circumference, increases girth and makes annual rings. Intercalary: at the base of internodes or above nodes, regrowth after cutting or grazing. (2)
Meristematic cells are small with thin walls, a large nucleus, dense cytoplasm and no vacuoles or intercellular spaces. (1)

Answer: Apical (length), lateral (girth), intercalary (regrowth); small thin-walled cells with large nucleus and no vacuole.

Example 2: Collenchyma and sclerenchyma · 3 marks · Short answerBoard level

Give three differences between collenchyma and sclerenchyma, and one place where each is found.

Try it first, then show the solutionSolution

Cells: collenchyma is living; sclerenchyma is mostly dead. (1)
Wall: collenchyma is thickened at the corners with pectin; sclerenchyma is thick all round with lignin. Job: flexible support versus strength and hardness. (1)
Places: collenchyma in leaf stalks, young stems and tendrils; sclerenchyma in seed coats, coconut husk and walnut shell. (1)

Answer: Living versus dead, pectin versus lignin, flexible support versus strength; leaf stalk versus coconut husk.

Example 3: Reading annual rings · 5 marks · Long answerHarder board level

A cross-section of a tree trunk shows rings whose widths from the centre outwards are, in mm: 3, 5, 6, 2, 4, 5, 1, 4.
(a) How old is the tree? (1)
(b) Find the radius of the wood. (1)
(c) Which years were the best and the poorest for growth? (1)
(d) Find the mean radial growth per year. (1)
(e) Name the tissue that makes the rings and explain the narrow ring. (1)

Try it first, then show the solutionSolution

(a) There are 8 rings, so the age is 8 years. (1)
(b) Radius = 3 + 5 + 6 + 2 + 4 + 5 + 1 + 4 = 30 mm. (1)
(c) The widest ring (6 mm, year 3) marks the best year; the narrowest (1 mm, year 7) marks the poorest year. (1)
(d) Mean growth = 30 ÷ 8 = 3.75 mm per year. (1)
(e) The lateral meristem adds a layer of wood each year; a narrow ring means poor growing conditions that year, such as scarce water. (1)

Answer: (a) 8 years; (b) 30 mm; (c) year 3 best, year 7 poorest; (d) 3.75 mm per year; (e) lateral meristem, poor conditions.

Example 4: Following the dye in a stem · 5 marks · Long answerHarder board level

A leafy twig is placed in red-coloured water. After 30 min the dye has risen 12 cm in the stem, and thin red lines show in a thin cross-section.
(a) Find the rate at which the dye rises, in cm per hour. (1)
(b) At the same rate, how far does it rise in 2.5 h? (1)
(c) Name the tissue that carries the dye and the materials it normally carries. (1)
(d) Name the tissue that carries sugars and say in which direction it can carry them. (1)
(e) Which cells of the first tissue are living? (1)

Try it first, then show the solutionSolution

(a) 12 cm in 0.5 h = 24 cm per hour. (1)
(b) 24 × 2.5 = 60 cm. (1)
(c) Xylem, which carries water and minerals upward from the roots (and gives strength). (1)
(d) Phloem carries food (sugars) from the leaves to other parts, upward or downward. (1)
(e) Only the xylem parenchyma is living; tracheids, vessels and fibres are dead, thick-walled cells. (1)

Answer: (a) 24 cm per hour; (b) 60 cm; (c) xylem; (d) phloem, up or down; (e) xylem parenchyma.

Example 5: Cut grass, cut tip and a carrot cell · 4 marks · Case-basedHOTS / competency

Grass cut to 3 cm regrows 1.5 cm per day. A young sapling's tip is cut off, and it does not grow taller for weeks, though its stem thickens a little each year. In 1958 F. C. Steward grew a whole carrot plant from single phloem cells.
(a) How many days does the grass need to reach 12 cm? (1)
(b) Explain why the grass regrows after cutting, but the sapling does not grow taller. (1)
(c) Name the meristem that thickens the sapling's stem and the structure it leaves in an old trunk. (1)
(d) What does Steward's result show about differentiated plant cells? (1)

Try it first, then show the solutionSolution

(a) (12 − 3) ÷ 1.5 = 6 days. (1)
(b) The grass has intercalary meristem at the base of the blades, which is not removed by cutting. The sapling's apical meristem at the tip was removed, and that is the tissue that increases length. (1)
(c) The lateral meristem thickens the stem and leaves annual rings. (1)
(d) Differentiated cells can lose their specialisation, divide and differentiate again, so a single cell can grow into a whole plant: the basis of tissue culture. (1)

Answer: (a) 6 days; (b) intercalary meristem remains, apical meristem was cut; (c) lateral meristem, annual rings; (d) cells can redifferentiate into a whole plant.

Where students lose marks in Plant Tissues: Meristematic and Permanent

The slips examiners see most often, and what to write instead.

Mistake: Saying the xylem carries food.
Xylem and phloem are confused.
Wrong working
Xylem carries food from the leaves to the roots.
Right working
Xylem carries water and minerals upward; phloem carries food from the leaves.
Do this: Xylem = water, phloem = food.
Usually costs: 1 mark.
Mistake: Calling all permanent tissue dead.
Sclerenchyma and xylem vessels are dead.
Wrong working
Permanent tissues are dead cells.
Right working
Parenchyma, collenchyma and phloem cells are living; only sclerenchyma and most of xylem are dead.
Do this: State living or dead for each tissue.
Usually costs: 1 mark.
Mistake: Placing the lateral meristem at the tip.
'Lateral' is not linked with 'side'.
Wrong working
Lateral meristem is at the root tip.
Right working
Lateral meristem is a ring along the side of the stem and gives girth.
Do this: Lateral = side.
Usually costs: 1 mark.
Mistake: Writing that parenchyma has thick lignified walls.
Tissues are mixed up.
Wrong working
Parenchyma has lignin for strength.
Right working
Parenchyma has thin walls; lignin is in sclerenchyma.
Do this: Parenchyma = thin, soft.
Usually costs: 1 mark.
Mistake: Dividing by the wrong time in a rate question.
The time is given in minutes but the rate is asked per hour.
Wrong working
12 cm in 30 min = 12 ÷ 30 = 0.4 cm per hour
Right working
12 cm in 0.5 h = 24 cm per hour
Do this: Convert minutes to hours.
Usually costs: 1 mark.

Exam tips

Use a table comparing the three simple tissues on cell state, wall, spaces, job and location.
For xylem and phloem, list the parts and mark which are living.
Draw and label a longitudinal section of xylem and phloem with sieve plates and companion cells.
In ring questions count rings for age and sum the widths for radius.
Always link structure to function when asked why a tissue has a particular feature.

Practice questions on Plant Tissues: Meristematic and Permanent

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

Q1 · 2 marks · Very short answerBoard level
Why are meristematic cells small, thin-walled and free of vacuoles, and what is the use of the large nucleus?
Hint
These cells divide very quickly.
Answer
Small cells with thin walls and dense cytoplasm can divide quickly, and there is no room or need for large vacuoles or intercellular spaces (1 mark). The large nucleus controls the repeated cell division (1 mark).
Q2 · 3 marks · Short answerHarder board level
A tree trunk has 25 annual rings with a mean width of 2.4 mm. (a) Find the age of the tree and the radius of the wood. (b) If the trunk is 12 cm across (wood only) at ring 25, check that it agrees. (c) State what a very narrow ring tells us.
Hint
Radius = rings × mean width.
Answer
(a) Age = 25 years; radius = 25 × 2.4 = 60 mm (1 mark). (b) Diameter = 2 × 60 = 120 mm = 12 cm, which agrees (1 mark). (c) A very narrow ring means poor growth that year, for example a dry year (1 mark).
Q3 · 2 marks · Assertion-reasonBoard level
Assertion (A): Collenchyma allows a leaf stalk to bend without breaking. Reason (R): The walls of collenchyma cells are thickened at the corners with pectin. Choose: (a) A and R both true, R explains A; (b) A and R both true, R does not explain A; (c) A true, R false; (d) A false, R true.
Hint
Pectin behaves a little like rubber.
Answer
(a). The pectin-thickened corners give support but keep the tissue flexible, so the stalk can bend without breaking.
Q4 · 3 marks · Short answerHarder board level
Name the tissue described and one place where it occurs: (i) living cells, thin walls, many air spaces, store food; (ii) dead cells with lignified walls that form a coconut husk; (iii) living tubes joined by sieve plates with companion cells.
Hint
Think of wall thickness and the living or dead state.
Answer
(i) Parenchyma, in soft parts of stem, root, leaf or fruit (1 mark). (ii) Sclerenchyma, in the coconut husk, seed coats (1 mark). (iii) Phloem, which carries food from the leaves (1 mark).
Q5 · 4 marks · Case-basedHOTS / competency
A student places a leafy twig in red water for 2 h and finds the dye has risen 30 cm. (a) Find the rate in cm per hour. (b) Name the tissue that carried the dye. (c) When the leaves are covered with polythene, the rate falls; give a reason using transpiration. (d) Which tissue would carry sugar made in the leaves to the root, and in which direction does it work?
Hint
Transpiration creates a pull on the water in the xylem.
Answer
(a) 30 ÷ 2 = 15 cm per hour (1 mark). (b) Xylem (1 mark). (c) Covering the leaves stops transpiration, so the pull that draws water up the xylem is reduced and the rate falls (1 mark). (d) Phloem, which carries food from the leaves up or down to other parts, here down to the root (1 mark).

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1.Which meristem increases the girth of a stem?Show answer
Lateral meristem.
2.Which tissue carries water and minerals upwards?Show answer
Xylem.
3.What makes the walls of sclerenchyma hard?Show answer
Lignin.
4.Name the pores in the leaf epidermis.Show answer
Stomata.
5.Which cells control the sieve tubes in phloem?Show answer
Companion cells.
6.What does a wide annual ring show?Show answer
A good growing year.

Plant Tissues: Meristematic and Permanent: frequently asked questions

Why does grass grow back after mowing?

It has intercalary meristem at the base of its blades, which keeps dividing after the top is cut.

What is differentiation?

The change by which cells formed by a meristem lose the power to divide and take on a specific shape and function.

Why are desert plants' cuticles thick?

A thick waxy cuticle reduces water loss.

Is cork living tissue?

No. Cork cells are dead and waterproof; they form the bark made by the cork cambium.

What is transpiration good for?

It creates a pull that draws water up the xylem and also helps remove wastes.