1. Plant Biology
Form and Function

2. What are we learning today?
Benchmark:
SC.912.L.14.7 – Relate the structure of each of the major plant organs and tissues to physiological processes. AA
Objectives:
Identify the major plant organs
Discuss the functions of the various plant organs

3. What is the essential question?
Plants are complex multicellular organisms with many organs and structures that allow them to carry out all of life’s processes. How do these organs and structures function?

4. What are the types of tissues found in plants?
Plant tissues are organized into three systems:
Dermal tissue is like the “skin” of a plant in that it is the outmost layer of cells.
Vascular tissue is like the plant’s “veins,” transporting water and nutrients throughout the plant, and
Ground tissue is everything else. Ground tissue is made of cells whose cell walls have different thickness.

5. What is vascular tissue?
Forms transport system that moves H2O and nutrients through the plant
Made up of a network of hollow connected cells
Xylem, a H2O conducting tissue,
Phloem, a food conducting tissue,

6. Organs of the Plant
Plants have 3 main organs:
Roots
Stems
Leaves

7. Root Form and Function Two types of roots systems in plants:
Taproots
Fibrous roots
Roots are made up of a
Root cap protects the growth zone of the root
Root hairs increase water absorption rate
Root Functions
Anchor and support the plant
Absorb water and dissolved nutrients from the soil
Store food and water.

8. Root Structure

9. Root Form and Function How is a taproot different from a fibrous root?
What are the two main functions of roots?
How does a root prevent erosion?
How are the roots of most plants adapted to perform the major root functions?
How root hairs increases the ability of a plant to absorb water from the soil the plants grows in?

10. Stem Form and Function
Stem shape and growth are adaptations to the environment
Stems grow in length and thickness
Stems have several functions
Transport materials between a plant’s roots and its leaves
Support leaves and other structures
Store food and water

11. How do plants grow in length?
Meristems are clusters of tissue that are responsible for continuing growth throughout a plant’s lifetime.
The new cells produced in meristematic tissue are undifferentiated.
An apical meristem is a group of undifferentiated cells that divide to produce increased length of stems and roots.
Plants grow as long as they live.
Undifferentiated means that they have not yet become specialized for specific functions.
All cells originated in meristems look very much alike. Gradually, these cells develop into mature cells with specialized structures and functions, a process called differentiation.

12. What is primary and secondary growth?
Primary growth is a type of plant growth that occurs at the tips of roots and shoots
produced by cell divisions in the apical meristem.
Increases length
Secondary growth is the type
of growth that increases the plant’s
stem width (makes it thicker).
Via the cork cambium and
vascular cambium

13. How do plants transport water?
Three processes combined to move water up in a tree
Root pressure
Capillary action
Transpiration
Pressure created by water entering the tissues of a root can push water upward in a plant stem.
However, root pressure does not exert enough pressure to lift water up into trees.
How do plants fight against gravity?
To the Teacher: Use the analogy of a very tall building to understand the problems a large tree like General Sherman (Height feet, Circumference feet, Maximum Diameter - 36 feet. ) to get water to the top.

14. How does capillary action work?
H2O molecules are attracted to one another by a force called cohesion.
H2O molecules can also be attracted to other substances resulting from a force called adhesion.
H2O is then attracted to the walls in xylem, and H2O molecules are attracted to one another.
The tendency of H2O to rise in a thin tube is called capillary action.
Cohesion is the attraction of molecules of the same substance to each other.
Adhesion is the attraction between unlike molecules.
The thinner the tube, the higher the water will rise inside it.

15. Stem Form and Function What are the three main functions of stems?
How do the functions of a stem relate to the roots and leaves of a plant?
Describe how water is transported through a plant?
What is the difference between primary and secondary growth?

16. Leaf Form and Function Main organs that carry out photosynthesis
Most leaves are flat to absorb sunlight
Leaves have small openings called stomata (stoma) that control gas exchange and water loss.
A major limitation of photosynthesis is insufficient water
Tiny structures called guard cells control the size of the stomata.

17. Leaf Form and Function What is the function of the stomata?
What is the function of guard cells?
What is function of leaf veins?
Would a 10 foot tree with no leaves but healthy roots be able to move water to its top? Explain your answer.
How does the thin, flat structure of leaf helps increase the efficiency of photosynthesis?
How does a leaf structure is an adaptation that allows intake of carbon dioxide with minimal water loss?
Vein
Leaf cross section
Mesophyll
CO2 O2
Stomata

18. Seed Form and Function
Seeds are the reproductive structure that contains a plant embryo
Seeds store food that the embryo uses for germination
Seeds have a protective coat (Cotyledon)
Seed may contain one (monocot) or two (dicot) seed coats.

19. Flower Form and Function
Flower: Modified leaves
Reproductive structure of angiosperms
During pollination, pollen (the male gamete) is transferred from the stamen to the stigma
Many attract animals
Others are wind pollinated
After fertilization it develops into a fruit.
Aids in dispersal of seeds
Protects the seed

20. Draw and label the parts of the flower Male parts: -Stamen (anther and
Filament)
Female parts:
-Carpel
Stigma
Style
Ovary

21. Cone Form and Function
Reproductive organ of gymnosperms (“naked seeds”)
Male cones produce sperm
Female cones produce eggs.
Wind pollinated
After fertilization, a seed develops
Seeds are not enclosed in protective fruit.
Most gymnosperms are hermaphrodites (see picture). Why would it bear male cones on the lower branches, below the female cones?

22. Reproduction Form and Function
How are the different part of a flower involved in reproduction?
Why is it adaptive for some seeds to remain dormant before they germinate?
Why did the development of the seed was a major factor in the success of plants?
How do the flowers of wind-pollinated plants differ from the flowers of animal-pollinated plants?
How might it be an advantage for a plant to have many flowers together?
Why might wind-pollinated plants create more problems for allergy sufferers than animal-pollinated plants?

23. What is the essential question?
Plants are complex multicellular organisms with many organs and structures that allow them to carry out all of life’s processes. How do these organs and structures function?

24. Independent Practice: EOC workbook
Page 78-83