Grade 10 ยท Molecular, Cellular & Tissue Level ยท Lesson 4

Plant & Animal Tissues

Cells don't work alone โ€” they group into tissues, each specialised for a particular job. Explore the seven plant tissue types and see how tissue specialisation gets underway in animals too.

What is a tissue?

A tissue is a group of similar cells, working together, that perform a particular function. Individual cells become specialised (differentiated) for a specific job โ€” this is called cell differentiation.

The seven plant tissues

Plants have several distinct tissue types, each built for a specific role. Explore each one in detail in the Explore tab.

TissueFunction
MeristematicUndifferentiated, actively dividing cells found at root and shoot tips โ€” responsible for growth
EpidermisA protective outer layer covering the whole plant
ParenchymaPacking and storage tissue; also carries out photosynthesis in leaves
CollenchymaFlexible support in young, growing stems
SclerenchymaRigid support; cells are dead at maturity, with thick, hardened walls
XylemTransports water and minerals; made of dead, hollow cells forming tubes
PhloemTransports manufactured food (sugars); made of living cells
In a stem or root, these tissues are arranged in specific patterns that can be seen in cross-section under a microscope โ€” you'll study this arrangement in more detail in the next lesson on transport in plants.

Animal tissues โ€” an introduction

Just like plants, animal cells differentiate into specialised tissues suited to a particular structure and function. This is only a brief introduction here โ€” you'll explore specific animal tissue types (such as bone, cartilage, and muscle) in more depth in the next lesson on support systems in animals.

Same idea, different scale: cells โ†’ tissues โ†’ organs โ†’ organ systems โ†’ organism.

Plant Tissue Explorer

Click each tissue type to see a simplified cross-section and learn its function.

Meristematic tissue
ROOT & SHOOT TIPS
Small, tightly-packed, undifferentiated cells that divide rapidly by mitosis, producing new cells for growth in length.
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Review the explanations above.
Answer in your exercise book.
Question 1 ยท (2 marks)
Define the term "tissue".
Question 2 ยท (4 marks)
Name FOUR plant tissues involved in support, and state which are living and which are dead at maturity.
Question 3 ยท (4 marks)
Distinguish between xylem and phloem in terms of what they transport and their cell structure.
Question 4 ยท (2 marks)
Where is meristematic tissue found, and why is this location important for plant growth?
Question 5 ยท (3 marks)
Arrange the following in order from simplest to most complex: organ, cell, tissue, organism, organ system.
Question 6 ยท (6 marks)
A learner examines three plant tissues under a light microscope and measures the diameter of each cell/vessel as it appears in the eyepiece, at the magnification shown:

TissueImage diameter measured (mm)Magnification used
Parenchyma cell15ร—150
Xylem vessel8ร—100
Sclerenchyma fibre5ร—200
Use the formula: Actual size = Image size รท Magnification (remember 1 mm = 1000 ฮผm).
(a) Calculate the actual diameter, in micrometres (ฮผm), of the parenchyma cell. (2)
(b) Calculate the actual diameter, in micrometres (ฮผm), of the xylem vessel and the sclerenchyma fibre. (2)
(c) The sclerenchyma fibre has by far the smallest actual diameter of the three. Suggest why a narrow lumen (internal space) with very thick surrounding walls suits sclerenchyma's role in the plant. (2)