Activity 9

By researching cell division, I can explain its role in growth and repair and can discuss how some cells can be used therapeutically SCN 4-13a

I can debate the moral and ethical issues associated with some controversial biological procedures SCN 4-13c

http://www.eurostemcell.org

Task 1 Lesson Starter

Here are the opening paragraphs from two websites introducing genetic engineering – which one is Greenpeace and which is Monsanto – a Multinational Agricultural Biotechnology Company?

1. Today, biotechnology holds out promise for consumers seeking quality, safety and taste in their food choices; for farmers seeking new methods to improve their productivity and profitability; and for governments and non-governmental public advocates seeking to stave off global hunger, assure environmental quality, preserve bio-diversity and promote health and food safety.

2. Genetic engineering enables scientists to create plants, animals and micro-organisms by manipulating genes in a way that does not occur naturally. These genetically modified organisms (GMO) can spread through nature and interbreed with natural organisms, thereby contaminating non 'GE' environments and future generations in an unforeseeable and uncontrollable way. Their release is 'genetic pollution' and is a major threat because GMOs cannot be recalled once released into the environment.

Task 2

http://www.eurostemcell.org/films/a-stem-cell-story/English (15mins)

Video on IVF production of Stem Cells and Ethical Issues (4.5mins)http://www.bbc.co.uk/learningzone/clips/stem-cell-research-and-medicine/6013.html

1 stem cell

Self renewal – makes sure stem cells don’t run out

Why self-renew AND differentiate?1 stem cell

4 specialized cells

Differentiation - replaces dead or damagedcells throughout your life

Stem cells in your body = Tissue stem cellssurface of the eye brain

skin breast

muscles intestines (gut)

bone marrow

Blood stem cells: A type of tissue stem cell

blood stem cell

found in bone marrow

differentiation

only specialized types of blood cell

white blood cells

red blood cells

Blood stem cells in action

Why are scientists so interested in stem cells?Scientists around the world are trying to1. understand how and why stem cells can self renew and

differentiate.

2.They want to use them to help understand about human development.

3.Find out if they can be used to treat disease.

4.Use them as human stem cell models to help understand what goes wrong in cells.

5. Have more realistic ways to test new treatments on human cells

The challenge

The big challenge for scientists is to learn how to control these fascinating cells.

If we could force stem cells to make whatever kind of cell we want, then we would have a powerful tool for developing treatments for disease.

Example, perhaps we could grow new pancreas cells to transplant into the pancreas of a patient with diabetes, which could then make it’s own insulin to control blood sugar levels.

embryonic stem cells

skin

liver

neurons

ES cells can make many kinds of specialised cells in the lab!

Embryonic stem cells

blastocyst - a very early embryo (5

days)around 100-150 cells

One cell removed and grown in a dish in a lab

Induced pluripotent stem cells – iPS cells

These cells were first made in a laboratory by a scientist in 2006. iPS cells are made by adding four special genes to a tissue stem

cell and these reprogrammed the cell. What was produced was a cell that could make any cell type. Therefore it was very similar to an embryonic stem cell.

The scientist who created it thought this would help alleviate the controversial issues surrounding embryonic stem cells.

http://www.eurostemcell.org/factsheet/reprogramming cells

Task 3

Complete the Worksheet on Stem Cells using the work cards and the information that you have gathered in this lesson.

Activity 2 – ExtensionComparing Embryonic and Tissue Stem Cells

Comparing Embryonic and Tissue Stem Cells

These are cells found in many areas of the body that need to be renewed throughout the life of the person.

However these stem cells are already partly specialised and will only make up all the cell types of the tissue they are found in.

e.g blood stem cells make all the different cells of the blood, Skin stem cells make all the different cells of the skin.

It is much easier and less controversial to grow these stem cells in the laboratory and cells can be taken from a patient

Why might Scientists not find these stem cells as useful as Embryonic stem cells?

Or maybe they have other advantages over Embryonic stem cells?

What we’ve learnt today - Summary

Stem cells can:• Self-renew = copy themselves• Differentiate = make other types of cell

There are different kinds of stem cell:• Tissue stem cells – in our bodies all our lives

– only make particular cell types• Embryonic stem cells – in the early embryo

– can make all the cells of the body• iPS cells – reprogrammed tissue stem cell

– can make all cell types of the body We need stem cells to…• Replace cells that die or get damaged• In the future, we might use them to treat diseases or test drugs