1. Multicellular Organisms
Key Area 2.1
Cells, tissues and organs

2. Cell Specialisations Learning Intention:
To learn about multicellular organisms by viewing cells and tissues using a microscope
Success Criteria:
Be able to define the term “multicellular organism”
Describe the organisation of cells, tissues and organs in a multicellular organism

3. Starter Activity
In your pair, discuss the structures found in a typical animal cell and their functions
Discuss the structures found in a typical plant cell and their functions
Name three other types of cell that you have studied so far
Twig: What is a cell?

4. Think, Pair, Share What is a unicellular organism?
What is a multicellular organism?
Give two examples of each

5. Unicellular organisms
Paramecium
Euglena
Yeast
Amoeba
Bacteria

6. Multicellular organisms

7. Multicellular organisms
Multicellular organisms are made up of more than one cell.
These cells can be organised into tissues and organs.
Twig: Tissues

8. What do all of these cells have in common?

9. Cell specialisations
The cells on the previous slide all have typical structures such as:
cytoplasm
cell membrane
cell wall
nucleus
chloroplasts
However, the structure each type of cell is different so that it can carry out a particular function.

10. What is a specialised cell?
Plants and animals consist of many cells and so are known as multicellular.
They contain many different types of cell.
Each type of cell is designed to carry out a particular job or function.
This is known as cell specialisation.
Twig: Different types of cell

11. Did You Know?
There are over 100 different types of cell in the human body!
These are just a few examples………..

12. Head contains nucleus and mitochondria
Sperm cell
Head contains nucleus and mitochondria
Tail
Sperm cells swim towards the egg to carry out fertilisation. They have a tail to enable them to swim and many mitochondia for producing energy.
Twig: Sperm cell

13. Egg cell (ovum) Made in the ovaries of mammals.
Cytoplasm containing food store
Made in the ovaries of mammals.
An egg cell is large compared to sperm.
Contains a food store in the cytoplasm for nourishing the embryo.
Nucleus
Twig: Egg cell

14. Ciliated cell nucleus Help to prevent dust and bacteria entering lungs
Line the windpipe (trachea)
Have tiny hairs called cilia
Cilia sweep mucus with trapped dust and bacteria up to mouth to be swallowed
cilia

15. Nerve cell (neurone) Longest cells in the body
extension of the cytoplasm (axon)
nucleus
Longest cells in the body
Transmit electrical nerve impulses in body
Twig: Nerve cell

16. Red blood cell No nucleus
Contain haemoglobin to carry oxygen around the body
“Biconcave” shape for large surface area
Twig: Blood

17. Palisade mesophyll cell
Found in leaves of plants
Packed with chloroplasts to trap light for photosynthesis
nucleus
chloroplasts

18. Root hair cell
Root hair increases surface area for uptake of water and minerals from soil
Thin cell wall so water can move in easily
thin cell wall
root hair
cell membrane
vacuole

19. Cell Specialisations Task
Your teacher will provide a worksheet for this task
Use your knowledge of cells to name each cell in the worksheet
Write how the structure of each cell allows it to carry out a particular function

20. Cell Specialisations Task
Check your work using the table opposite
You may have remembered additional information!

21. Tissues Learning Intention:
To learn about different tissues in animals and plants
Success Criteria:
View tissues using a light microscope
Be able to identify and name different types of tissue

22. Tissues What are tissues?
Can you give some examples of tissues in the human body?
Can you give some examples of tissues in plants?
What is the difference between tissues and organs?

23. Tissues Tissues are groups of cells that perform the same function.
Examples of human tissues include epithelial tissue and muscle tissue.
The study of tissue is known as histology or, in connection with disease, histopathology.

24. Tissues

25. Epithelial tissue
Epithelial tissue covers body surfaces and lines cavities and tubes.
These include the airways and digestive tract.
Some epithelial tissue is specialised to form glands like oil and sweat glands in the skin.

26. Muscle tissue
Muscle tissue helps in body movement because it can contract and relax.
There are three different types of muscle tissue:
cardiac
skeletal
smooth

27. Smooth muscle tissue
The structure of these cells allows them to perform a specific function
Are spindle shaped
Can contract and relax
This allows the cells to slide easily across one another

28. Smooth muscle tissue

29. Plant tissues
Plants also have different types of cells that are grouped together into tissues.
In each case, the structure of each cell is related to its function.
Plant tissues include epidermal, palisade mesophyll and spongy mesophyll.

30. Epidermal tissue Epidermal cells fit together like a jigsaw
From Greek word meaning “over-skin”
Create a strong and protective layer on the outside of leaves, roots and stems
epidermal

31. Palisade mesophyll tissue
These cells have many chloroplasts to trap light for photosynthesis
Are column shaped so that they can be densely packed near the surface of the leaf
palisade mesophyll

32. Spongy mesophyll tissue
These cells have a rounded shape
This allows them to be loosely arranged so that they can take up carbon dioxide by diffusion
Carbon dioxide can then be used for photosynthesis
spongy mesophyll

33. Cross section through a leaf

34. You are a histologist for the day!
Histology Task
You are a histologist for the day!
You must…
Use a light microscope to view slides of different tissues.
You should…
Use your knowledge of tissues to name each tissue type: can you name which part of the organism it comes from?
You could…
Make a pencil drawing of what you see and record how the structure of each cell type allows it to perform a specific function: do this for at least four different tissues.
Tissue 1:______
Tissue 2:______
Tissue 3:______
Tissue 4:______
Record your observations on one full page in your note book or on one piece of A4 paper.

35. Organs A group of tissues working together form an organ.
Examples of animal organs include the heart, lungs, brain and kidneys.
Examples of plant organs include roots, stems, flowers, seeds and fruits.

36. Systems
A group of related tissues and organs eg. blood, heart, arteries, capillaries and veins make up a system.
The tissues an organs above make up the circulatory system.

37. Systems Examples or organ systems in animals include: skeletal
muscular
digestive
respiratory
nervous
circulatory

38. Systems
Examples of organ systems in plants include the vascular system in the roots and shoots.
This includes xylem and phloem. You will learn about these specialised cells later.

39. Summary
Cells have different ___________ that allow them to carry out a particular__________.
These are known as cell specialisations.
Many __________ cells working together form a __________.
A group of tissues that work together form an ___________.
Organs are found in both _______ and plants. A group of related tissues and organs form a __________.
animal
specialised
organ
tissue
structures
function
system

40. Summary
Cells have different _________ that allow them to carry out a particular__________.
These are known as cell specialisations.
Many __________ cells working together form a ______.
A group of tissues that work together form an _______.
Organs are found in both _______ and plants.
A group of related tissues and organs form a __________.
structures
function
specialised
tissue
organ
animal
system

42. Key Area 2.1 Consolidation Tasks…
You must complete…
In the back of your notebook: Exercise 1 & 2 from the new unit 2 homework booklet.
Review your KA 2.1 cells, tissue & organs key words.
Review your KA 2.1 cells, tissues & organs learning outcomes.
You should complete…
N5 Text book: Read page 114 – 118
In the back of your notebook: complete Activity (p116) & Activity (p118)
You could complete…
On plain A4 paper: Activity (p116) & Activity (p118)
Collect 4 study cards and create quiz cards (questions & answers) about cells, tissues & organs.