1. Ch. 8 Cell Diversity

2. cell – tissue – organ - system
Defn: A cell is the smallest basic unit of living things Defn: A tissue is a group of similar cells that are modified (or adapted) to carry out the same functions Simple Tissue = 1 cell type Complex Tissue = > 1 cell type

3. Plant Tissue (need to know 2)
Main types
1.Dermal 2. Vascular 3. Ground 4. Meristematic
Dermal Tissue
A single layer of cells that surrounds different parts of a plant.
E.g. The Epidermis

4. E.g. The Epidermis Location An outer covering on leaves, stems & roots
Description
Living, rectangular shaped cells
Slightly thickened cell wall
Can have a waterproof layer called the Cuticle on outer surface
Function
Protection
Waterproofing if Cuticle is present

5. (2) Vascular Tissue Transportation of minerals around plant
A complex tissue – 2 types of cells i.e. xylem & phloem

6. Xylem
Description
Hollow tubes running from root, through stem & into leaves
Function
Transport water & dissolved minerals
Support in woody plants

7. Phloem Description Tube like structures Found in leaves, stems & roots
Function
- Transport food from leaves to other parts of plant

10. Animal Tissue
4 main types: Epithelial, Connective, Muscular (can contract) & Nervous Tissue **need to know 2 in detail

11. Connective Tissue connects/binds other tissues together
E.g.'s Adipose tissue (stores fat),
Cartilage,
Bone
Blood

12. Blood Tissue Consists of: - red cells (carry oxygen),
- white cells (defence)
platelets (clot blood)
All suspended in a liquid called plasma

13. Nervous tissue Description Compound of nerve cells called Neurons
Function
Neurons carry electrical impulses to & from brain & spinal cord

14. Learning Check Can you name 3 types of cell? What is a tissue?
Can you recall 2 types of animal tissue?
Can you recall 2 types of plant tissue?

15. Tissue culture
Defn: Tissue culture is the growth of cells in or on a sterile nutrient medium outside an organism
How it works?
A tissue sample is removed from a plant or animal & grown in glassware (in vitro – outside the body) in a bath of sterile nutritive fluid which often contains hormones and growth substances

16. Growth is by mitosis and produces a cluster of identical offspring - a clone
Main conditions necessary for Tissue culture
Absence of contaminating microorganisms
Food, vitamins & minerals
Substances to stimulate growth (e.g hormones)
Oxygen
Correct pH

17. Q. Suggest a reason why sterile conditions are needed in tissue culture?
A. to prevent bacterial growth or contamination

18. Stages in Tissue Culture
Example of tissue culture is Organ transplants
Skin cells obtained
Enzymes added
Individual Cells isolated
Controlled culture medium
Sheets of cells grown

19. Applications of Tissue Culture
Plant breeding = Micropropagation
Cancer research
Skin grafts
**need to know 2

20. Applications of tissue cultures
Virus reproduction
Hela cells used to grow and investigate viruses
**Micropropagation of plants
Produces exact copies
Quickly produces mature plants
Doesn’t need pollinators or seeds
Producing plants that are disease resistant and virus free

22. Applications of tissue cultures
**Growing human tissue for organ transplants
Skin cells
Liver cell
Pancreas cells
Producing biotechnology products
Insulin
Interferon
Pregnancy testing kits
Drug testing kits
Cancer testing kits

23. (2) Skin Grafts
New skin can be grown from cells (usually stem cells)

26. Learning Check What is Tissue Culture?
What kind of conditions do cells in tissue culture need?
What are the stages of tissue culture?
Can you name two uses for tissue culture?

27. Organs
Defn: An organ is a structure composed of a number of tissues that work together to carry out one or more functions
Examples of Plant Organs: root, stem, leaves, flowers, stems & fruit
Examples of Animal Organs: stomach, brain, liver, kidney & heart

28. Need to know 1 E.g. of a Plant Organ
Organ: Leaf
Tissues it contains:
Dermal (found in Epidermis)
Vascular ( found in Vascular bundle as Xylem & Phloem tissue)
Ground ( found as Palisade & Mesophyll Cells)

29. Highlight Tissue types in the diagram in your book

30. E.g. of An Animal Organ Organ: Heart Tissues it Contains:
Muscle tissue called Cardiac Muscle
Enclosed in Pericardium (a membrane - contains epithelial tissue)
Connective Tissue ( blood & vessels)
Controlled by Nervous Tissue

31. An Organ System: consists of a number of organs working together to carry out one or more functions All organ systems combine to make the organism

32. Numerous organ systems in human
The Circulatory System: heart, blood vessels, blood & lymph Function: transport materials & fight infection The Digestive System: mouth, oesophagus, stomach, small intestine, large intestine & Anus Function: Take in food, break it down, & transfer it to the circulatory system.

33. Learning Check What is an organ? Can you name 2 plant organs?
Can you name 2 animal organs?
What is an organ system?
Can you recall 2 animal organ systems?