Structure of Flowering Plants

You need to know details on…

1. Structure & function of root and shoot systems

2. Root zonations and all outer stem parts

3. Meristem function / location in root & shoot

4. Location of 3 tissue types in transverse and

long sections of root and stem

5. Xylem & Phloem structure and function

6. Distinguish between Moncots and Dicots

7. Mandatory Activity….TS Dicot stem

3.2.1 Objectives

1 Label a diagram of the external parts of a

typical flowering plant

Shoot, root, stem, leaves, flower, fruit, seed.

2 State the function of the root and shoot

3 Identify tap and fibrous root systems

4 Explain the term Meristem and give its

location in the stem and root

5 Name and give the function of four zones in

a longitudinal section of a root

6 State the function of Vascular Tissue

7 Give the location of three tissue types,

Dermal, Ground and Vascular, in transverse

sections of the of the root and stem and leaf

8 Give the location of three tissue types,

Dermal, Ground and Vascular, in

longitudinal sections of the root and stem.

9 Identify and draw the structure of Xylem and

Phloem and state their function

10 Distinguish between Xylem Vessels and

Xylem tracheids, and between Phloem

Sieve Tube Cells and Companion Cells

11 Identify Monocots and Dicots under the

Headings

Number of flower parts

Vein pattern in leaf

Arrangement of Vascular Bundles

Number of Cotyledons in the seed

Woody or Herbaceous

12 Mandatory Practical:

Prepare and examine a transverse section of

a Dicot stem under the microscope

What Flowering Plant typically have

5. Flowers

3. Stems

6. Fruits & Seeds

1. Transport (Vascular) Structures

2. Roots

4. Leafs

Plants are divided into two portions

Over ground shoot

system

Under ground

root system

Meristem

Apical meristems are found

at the tip of the shoot and

tip of the root and give an

increase in length

An area of active cell division

Lateral meristems are

found around the edges of

some plants and give an

ìncrease in width

Root Functions

Anchor

Absorb Water

Absorb minerals

Transport absorbed materials to shoot

Store food

Two Root Types

Many equal sized roots

arising from stem base

eg grass

2. Fibrous Roots

1. Tap Roots

One main root growing

from the radicle

eg Carrot

Four Root Zones

Protection Zone

Meristematic Zone

Elongation Zone

Differentiation Zone

Root Zones

2. Ground Tissue

1. Dermal tissue

Here cells develop

into 3 different

types of tissue

Differentiation Zone

3. Vascular tissue

Here cells increase in

size

Elongation Zone

Root Zones

Root Zones

Here new cells are

produced by mitosis

divisions

Meristematic Zone

Root Zones

A root cap protects

the cells as the root

pushes through the

soil

Potection Zone

Learning Check 1

1. Name the two types of root system

2. Explain the term Meristem

3. Name the four zones in a root

4. What is the function of the root cap ?

Tissue location in the root (transverse section)

Vascular

Tissue

Phloem

Xylem

Dermal Tissue

Ground

Tissue

Tissue location in the root

(transverse section)

Vascular

Tissue

Phloem

Xylem

Dermal Tissue

Ground

Tissue

Tissue location in the root

(transverse section) (Center part of root)

Vascular

Tissue

Phloem

Xylem

Ground

Tissue

Tissue location in the root (Longitudinal section)

Vascular Tissue

Dermal Tissue

Ground Tissue

Dermal Tissue

Ground Tissue

Stem Functions

1. Support the arial

parts of the plant

2. Transport water and

minerals from roots to

leafs

4. Sometimes store food

3. Transport food from

leafs to roots

Function of outer stem parts

Terminal Bud

Increase stem length

Lateral Bud

Grow side branches

Lenticels

Gas exchange

A= Terminal Bud

D= Lateral Bud

C= Scale Scar

B= Leaf Scar

Lenticels

Year

3

Year

2

Year

1

Tissue location in stem

(Transverse section)

Vascular

Tissue

Phloem

Xylem

Dermal Tissue

Ground

Tissue

Tissue location in stem ( Longitudinal section)

Dermal

Ground

Vascular

Ground

Vascular

Ground

Dermal

Learning Check 2 ….. Label the diagram

Leaf parts

• Some leaves do not have a petiole (They are called sessile leaves)

• Veins contain the vascular tissue

Leaf Functions

1. Photosynthesis

2. Transpiration

3. Gas exchange

4. Sometimes store food

Tissue Location in the Leaf

Dermal Tissue

Dermal

Tissue

Vascular

Tissue

Ground

Tissue

Flower Function

Sexual

Reproduction

Vascular Tissue

1. Xylem

2. Phloem

Function

Function

Transport water

Transport minerals

Transport food

Xylem Structure….Two types of Cell

Xylem Tracheids Xylem Vessels

On maturity both

are dead, hollow

and contain no

cytoplasm

Found in conifers Found in deciduous trees

Xylem Tracheid Structure

Long cells tapered at both ends

Pits in the walls – allow water

and minerals to move

sideways from cell to cell

Walls thickened with

lignin for support

Xylem Vessels Structure

Elongated cells

Spiral lignin for

strength

No end walls – form a

continuous tube

Pits to allow sideways

movement of water

Nucleus controls

activities of

both companion

and sieve tube

cell

Phloem Structure

Sieve plates

Mature cells

have no

nucleus

Cytoplasm extends

from cell to cell

through the

sieve plate

2 Companion

Cells

1. Sieve tube

cells

Longitudinal and Transverse sections

Phloem

Example of Monocot and Dicot

Monocot Dicot

Grass Buttercup

Differences between Monocots & Dicots

Monocotyledons Dicotyledons

Number of

cotyledons

One Two

Arrangement of

vascular

bundles in the

stem

Scattered in the

stem

In a ring pattern

Leaf venation Parallel Netted

Number of

flower parts

In threes In fours and fives

Woody or

herbaceous

Almost all are

herbaceous

May be woody or

herbaceous

Identification of Monocots & Dicots

Learning Check 3

1. State two functions of a leaf

2. Distinguish between xylem vessels and

xylem tracheids

3. What is the role of the companion cell in

phloem tissue

4. How is a transverse section of a monocot

stem different to the TS od a Dicot stem ?

End