1. 4.1 Systems in Plants
Plants including mosses, ferns, conifers and flowering plants are all multicellular organisms
Plants have two obvious features:
they are typically green in colour
they cannot move from place to place
Their green colour is caused by chlorophyll, which is a chemical that plants use to photosynthesize
Plants all have structures to anchor them in place, these are usually roots
Chapter 4: Plant Systems, we just covered animal systems, plants are equally important, they are the primary producers of energy, convert solar energy from the sun into chemical energy
Do you think chlorophyll absorbs or reflects the green wavelength of light? Reflects it, that is why we can see it, chlorophyll absorbs all the other colours

2. We will be focusing on the structures in flowering plants
Other plants (mosses, ferns, conifers) have different structures
The plant body is divided into two main body systems:
Shoot System
Root System
Are animals made up of just to systems?

3. Plants perform photosynthesis to make their own food
This means that they do not need to move around in search of food
As a direct consequence, plants have no need for the complex organ systems found in animals, such as:
Musculoskeletal system (muscles, bones)
Nervous system (brain, spinal cord, nerves)
Digestive system (stomach, intestines)
Which we use to perform movements, sense our surrounds, ingest prey items

4. Plants need to exchange gases with their surroundings
However, plants do have to perform many of the same functions as animals
Plants need to exchange gases with their surroundings
They require an internal transportation system to move water and nutrients around within their bodies
They must have a way of reproducing
Respiratory system, circulatory system, reproductive system

5. Organization of the Plant Body
Because plants are so different from animals, the terminology that describes them is different as well
The root system is made up of one or more separate roots
The shoot system consists of the stem, leaves and flowers
Remember the differences between animals and plants goes all the way down to cell structure? Animal and plant cells differences, and cells makes up tissues, tissues make up organs, organs make up systems, systems make up organisms

6. There are three main types of plant tissue systems:
The dermal tissue system is made up of tissues that form the outer surfaces of plant parts
The vascular tissue system is made up of tissues specialized for the transportation of water, minerals and nutrients throughout the plant
The tissues in the ground tissue system make up all of the other structures within a plant

7. The Root System
The root system typically grows below ground which anchors the plant, absorbs water and minerals from the soil and stores food
Most of the water and minerals obtained by the plant are absorbed by root hairs: fine extensions of dermal tissue cells
Roots can also be above ground or above water
Huge variation in structure: carrots, beets, ginger

8. The Shoot System
The shoot system is the system that is specialized for two main functions:
conduct photosynthesis
produce flowers for sexual reproduction
Shoot systems are comprised of three parts:
leaf
flower
stem
Each has its own distinctive functions
Surviving (obtaining energy) and reproducing (making offspring) allows a species to persist

9. The Leaf The leaf is the main photosynthetic structure
During photosynthesis, tissues in the leaf use carbon dioxide (CO2), water (H2O) and light energy to produce glucose sugar (C6H12O6) and oxygen (O2)
Chlorophyll
Light Energy + CO2 + H2O C6H12O6 + O2

10. The cell structure that actually performs photosynthesis is an organelle called a chloroplast
Chloroplasts contain flat, disc-like structures called thylakoids, which are arranged in stacks called grana
The grana act as solar conductors by using chlorophyll in the membranes of thylakoids
Do animal cells contain chloroplasts?

11. Some leaves are also adapted for:
Support (tendrils on cucumber plant)
Protection (sharp spines on cactus)
Reproduction and attraction (red leaves on poinsettia)

12. The Flower
Flowers are specialized structures developed for sexual reproduction
They contain male or female reproductive structures, or sometimes both
Male reproductive structures produce pollen grains
Females reproductive structure produce eggs
Eggs are fertilized by pollen

13. After pollination, the female flower parts form seeds
In most flowering plants, the seeds are contained within a specialized structure called a fruit
Pollination occurs with the help of wind or animals
Colourful flowers and nectar production are plant adaptions to attract pollinators (insects, birds, bats)
Mosses, ferns, conifers do not flower and have different reproductive systems (ex: conifers – cones)

14. The Stem
The stem, or trunk in the case of trees, support branches, leaves, flowers and provides a way to transport materials between these different plant structures
The stem contains a significant amount of vascular tissue for carrying substances to and from roots, leaves, flowers and fruits
Some stems are specialized for food storage, protection, photosynthesis and reproduction
Huge variation: from sugar cane to maple trunk
Remember the three tissue types are dermal, vascular, ground, vascular is for transport

15. 4.2 Plant Tissue Systems
Plant tissues are classified into three tissue systems
Each tissue includes a variety of specialized cell types that enable them to carry out specific functions within the plant body
Just as in animals, these specialized cells develop from unspecialized cells during the process of cellular differentiation

16. Cellular Differentiation and Specialization in Plants
When a seed starts to grow, the cells divide very quickly
As the seed develops into an embryo, many of the cells start to differentiate into specific tissues
The regions of growth are located at the tips of the plant’s roots and shoots
Plants with woody stems (trees) also have a region of growth just below their stems

17. Plant growth occurs because undifferentiated cells are actively growing and dividing in these regions
As these new cells mature, some of them specialize and develop different features according to their location and future function
Ex: cells in leaves are very different from those in the roots and stem of the plant
Structure determines function

18. Meristematic Cells
Just as animals contain unspecialized cells called stem cells, plants have unspecialized cells called meristematic cells
These meristematic cells can differentiate into specialized tissue types
Germinating seed with meristematic cells differentiating into various plant structures

19. Tissue Systems in Plants
Each of the three tissue systems contains different types of specialized cells
The tissues of the three systems are found in all parts of the plant body and have a distinct arrangement

20. The dermal tissues cover the entire outer surface of the plant, but do not occur within the plant
The vascular tissue system is continuous, joining all plant parts together
The ground tissues account for all other internal tissues in the root, stem and leaves

21. Dermal Tissue System Outermost layer of plant
Includes both epidermal and periderm tissues
Epidermal tissue (epidermis): thin layer of cells that covers the surfaces of leaves, stems and roots
In woody plants the epidermal tissue is replaced by periderm tissue that forms bark on stems and large roots

22. Cells of the dermal tissue system are specialized to perform a variety of functions
Some epidermal root cells have root hairs = long extensions for absorption of water and minerals from soil
Most epidermal leaf cells produce a layer of wax called the cuticle that prevents water loss, others have spike for defence

23. Vascular Tissue System
The transportation system within the plant
Plants must be able to distribute the water and other substances absorbed by its roots
Plants must also be able to distribute the sugars and other substances produced by photosynthesis in its leaves
As the plant grows the “tubing” of this transportation system extends throughout the growing tips, maintaining connectivity

24. There are two types of vascular tissue:
Xylem:
Transports water and dissolved minerals upward from the roots
Solution travels along network to the stems and leaves
Made up of elongated cells
Hollow tubes with rigid walls
Cells do not contain organelles = no longer living tissue

25. Phloem:
Transports solutions of sugars produced by photosynthesis
As well as other dissolved nutrients and hormones throughout the plant
Food materials are transported downward from photosynthesizing leaves to stems and roots
Food materials are also transported upward from roots and stems to leaves
Made up of elongated cells
Cells are mature and functioning = alive

26. Don’t forget: All plants and animals use sugars to provide energy for cell processes = cellular respiration which requires oxygen
Ground Tissue System
The “filler” between the dermal and vascular tissues
Most of the cells of young plants are ground tissue cells
In green parts: make nutrients using photosynthesis
In stems: provide storage and support
In roots: store carbohydrates
Convert excess glucose into starch, store in roots, potato structure
Homework: 4.1 page 128 #2, 4, 5
4.2 page 133 #1-6