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National 5 Biology – Multicellular Organisms – Stem Cells and Meristems
Cells, Tissues and Organs
You have already learned the basic function of cells, but how do these cells work
together to make you the truly amazing organism that you are?
Some of the key words you will need to use during this section are:
Cell, tissue, organ, system, organism, specialisation
Learning Outcomes
You will be able to:

Explain the term ‘specialisation’ with reference to animal and plant cell.

Describe how the structure of a cell can relate to its function.

Describe the levels of organisation found in animals and plants.
Specialisation
Multicellular organisms are formed from a single fertilized egg (zygote) and
are made of many genetically identical cells working together. These cells
become specialised to form cells which are have a special shape or structure
to carry out particular functions.
Red blood cell
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Plant root hair cell
National 5 Biology – Multicellular Organisms – Stem Cells and Meristems
Levels of Organisation
Specialised cells that perform specific functions will group together and form
tissues. These tissues will then work together to form organs and these organs
will work collaboratively to form a system. Finally these systems will work
together to form an organism.
Learning Activity 1
1. Explain what is meant by the term ‘specialisation’ of cells in animals and
plants.
2. Describe the level of organisation found in animal and plants.
3. Collect and complete the ‘specialised cells’ handout, paste into your notes.
4. Collect and complete the ‘cellular organisation’ handout and paste into
your notes.
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National 5 Biology – Multicellular Organisms – Stem Cells and Meristems
Challenge task
Create a ‘Plant or Animal cell owner’s manual’.
Success Criteria
1. Two A4 pages have been halved and arranged into a booklet.
2. Each page contains a different type of plant cell.
3. Diagrams are to be at least half the page and drawn in pencil.
4. Diagrams/Organelles are labelled accurately.
5. The function of the cell is described.
6. Research is done into how the structure of the cell relates to its
function.
Peer Assessment
Get another group to assess your completed work. They will give 2 positive
comments and one thing that could have been improved. Use the above success
criteria to evaluate the piece of work.
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National 5 Biology – Multicellular Organisms – Stem Cells and Meristems
Stem Cells and Meristems
You know that many cells in an organism are specialised in order to perform
particular functions, but just how do these cells become specialised?
Some of the key words you will need to use during this section are:
Stem cell, specialisation, embryonic stem cells, adult stem cells, meristems
Learning Outcomes
You will be able to:

Explain what is unique about stem cells.

Describe the role of stem cells in animals.

Compare and contrast embryonic stem cells and adult stem cells.

Give examples of the current uses of stem cells in medicine.

Describe the role of meristems in plants.
Stem Cells
Stem cells are unspecialised cells in animals that have the potential to become
different types of cells. Stem cells are involved in growth and repair. They can
 Reproduce themselves by repeated cell division while remaining
unspecialised or undifferentiated.

Differentiate into specialised cells when required to do so.
There are two main types of stem cell: embryonic stem cells and adult stem
cells.
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National 5 Biology – Multicellular Organisms – Stem Cells and Meristems
Embryonic Stem Cells
These stem cells are found in embryos and have the ability to develop into any
type of body cell, allowing organisms to grow from a tiny organism into a fully
formed individual.
Adult Stem Cells
These stem cells are found throughout the body and are slightly more
specialised than embryonic stem cells. For example; stem cells found in the bone
marrow are only capable of becoming a variety of blood cell types.
Therapeutic value of stem cells

Tissue stem cells present in bone marrow are used in bone marrow
transplantation to treat cancers of the blood.

Repair of corneal damage has been successfully carried out using the
patient’s own stem cells at the edge of their cornea.

Human embryonic stem cells have been used to treat burn victims.

Embryonic stem cells may be able to provide treatment for a range of
disease like diabetes, Parkinson’s disease, multiple sclerosis and
Alzheimer’s disease.
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National 5 Biology – Multicellular Organisms – Stem Cells and Meristems
Ethical Issues

Research involving embryonic stem cells involves the destruction of
embryos, many people believe it is wrong to destroy embryos because
they have the potential to grow into a baby.
 Some people believe that the techniques used in stem cell research are
similar to those used in cloning, which many people oppose.
 Many people have safety concerns and fear transplanted stem cells
could become cancerous.
Learning Activity 1
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Sans MS, 14 pt, Bold
Your teacher will show you a short clip on stem cells. Watch the clip and answer
the questions below in sentences.
www.bbc.co.uk?learningzone/clips/stem-cell-research/6013.html
1. What do scientists hope stem cells will enable them to do?
2. What is the easiest way to obtain stem cells at the moment?
3. What are stem cells?
4. Why are stem cells special?
5. How could stem cells be used to help the woman shown in the clip?
6. What are the two main ethical issues surrounding the use of stem cells?
Learning Activity 2
Your teacher will give you each a different “Stem Cell
Opinion” card. Following class discussion of each
characters point of view, you will get into groups and
create a 2 minute presentation to argue why your
character’s viewpoint is right.
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12 pt
National 5 Biology – Multicellular Organisms – Stem Cells and Meristems
Stem Cell Therapy Assessment – Outcomes 2.2 and 2.3
2.2 Describing an application of biology
2.3 Describing a biological issue and its
effect on society
What you need to do:
What you need to do:
Explain what stem cell are
Identify an issue related to stem cell use.
Explain where stem cells come from.
Identify the potential impact of stem cell
therapy in the future.
Explain what stem cell therapy is.
Identify a specific use for stem cell therapy.
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National 5 Biology – Multicellular Organisms – Stem Cells and Meristems
Meristems
Unlike animals, plant growth is
restricted to special points called
meristems. Meristems are the site
of mitosis and produce nonspecialised cells, which have the
potential to become almost any type
of plant cell and contribute to plant
growth. Meristems can be found at
the tips of the roots and shoots
(apical
meristems) and within the
stem and roots (lateral meristems).
Learning Activity 3
1. What is a meristem?
2. Identify TWO locations in a plant where a meristem would be found.
3. Explain the difference between apical and lateral meristems.
4. Collect and complete the hand out ‘Meristems’ and stick into your
notes.
Research Task
Some plants can be cloned in a process called ‘Mericloning’ . Your task is to
find out the following:
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What is Mericloning?
-
Describe the process of mericloning.
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Give examples of plants which may be produced in this way.
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What are the benefits of mericloning?