Structure of Flowering Plants

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

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 partsVein pattern in leafArrangement of Vascular Bundles Number of Cotyledons in the seedWoody 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

Over ground shoot system

Under ground root system

External Structure of Flowering Plants

Label Diagram of flowering plant

Root Types

Many equal sized roots arising from stem base eg grass

3. Adventitious Roots

Roots that do not develop from the radicle. E.g. gripping roots of ivy.

2. Fibrous Roots

1. Tap Roots

One main root growingfrom the radicle eg Carrot

Root Functions

1. Anchor plant in the ground

2. Absorb Water

3. Absorb minerals

4. Transport absorbed materials to shoot

5. Store food

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

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

Protection Zone

Quiz

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

Year3

Year2

Year1

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 ofboth companion and sieve tube cell

Phloem Structure

Sieve plates

Mature cells have no nucleus

Cytoplasm extendsfrom cell to cell through thesieve 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