Science Bank: Biology
Programme 9: Cells and Tissues
Activity 1 worksheet: Exploring cell growth
This is an activity which may need to be done at school. Use prepared slides of a root tip to look at
cells and measure their size. Here’s what you do:
1. Set up slide on
microscope stage
microscope stage
clip holds slide in place
glass microscope slide
sample of root tip cells in this area
2. Use an acetate film with a one
centemetere scale accurately printed
on it
3. Place the scale on top of the microscope
slide, and secure it with the clips
scale printed
on acetate
0
1
2
3
4
5
6
7
8
9
10
cell of root tip
The centimetre is into ten millimetres.
Each millimetre is accurately divided
into tenths
How many cells fit along the part of the
scale which is 0.1mm?
Estimate the size of the cells by
comparing them to the scale
© 2000 Channel Four Television Corporation
page 1 of 6
Science Bank: Biology
Programme 9: Cells and Tissues
Activity 1 worksheet: Exploring cell growth
• Start at the tip of the root where you can see the outlines of cells clearly. Measure at least 5 cells.
•
•
What is their average length?
Move further back from the root tip and measure at least 5 cells.
Repeat this procedure and fill in the results’ table below.
position of sample moving back from the tip
average size of cells (mm)
1
2
3
4
4
5
6
7
8
9
10
• What happens to the size of cells as they get further back from the tip?
• What other changes can you see in cells between the tip and further back?
• Suggest two processes that happen when new cells at the root tip form and grow.
© 2000 Channel Four Television Corporation
page 1 of 6
Science Bank: Biology
Programme 9: Cells and Tissues
Activity 2 worksheet: DNA and identification
All around the world, scientists, medical charities and industries are working to discover where
genes are located on human DNA. This is called the Human Genome Project (HUGO). This
information is useful because many diseases are inherited, and knowing which genes are
responsible is a starting point for developing treatments.
The graphic shows a section of human DNA which has been treated so that the components show
up like a ‘barcode’ pattern. Each person (except an identical twin) has their own unique pattern, and
so this technique can be used to identify a sample of DNA from someone.
1. Why do humans have unique DNA?
2. Why do identical twins have almost identical DNA?
3. Which of the samples in the graphic are most likely to come from the same person? How can
you tell?
Try finding out more about how analysing DNA can help solve crimes. You can try some of these
search words on the net.
Forensic science
DNA analysis
HUGO
© 2000 Channel Four Television Corporation
page 3 of 6
Science Bank: Biology
Programme 9: Cells and Tissues
Activity 3 worksheet: What happens in mitosis?
Here are some diagrams showing the process of mitosis. This is the type of cell division that
happens in the human body when we are growing. Mitosis also happens throughout life to replace
worn out cells, for example especially in the skin.
In this activity you have to put the events of mitosis in the correct order. You may need to go back to
the video programme to find out more about this.
1. DNA forms chromosomes which replicate, becoming double-stranded.
2. Double strand chromosomes attach at the centre of the cell.
3. Single strands separate and move to opposite ends.
4. Nuclei start to form, the cell starts to divide, chromosomes disperse.
5. Two new identical cells are formed.
© 2000 Channel Four Television Corporation
page 4 of 6
Science Bank: Biology
Programme 9: Cells and Tissues
Activity 3 worksheet: What happens in mitosis?
Here are some diagrams showing the process of mitosis. This is the type of cell division that
happens in the human body when we are growing. Mitosis also happens throughout life to replace
worn out cells, for example especially in the skin.
The correct sequence of events in mitosis is shown below.
1
2
4
3
5
1. DNA forms chromosomes which replicate, becoming double-stranded.
2. Double strand chromosomes attach at the centre of the cell.
3. Single strands separate and move to opposite ends.
4. Nuclei start to form, the cell starts to divide, chromosomes disperse.
5. Two new identical cells are formed.
© 2000 Channel Four Television Corporation
page 5 of 6
Science Bank: Biology
Programme 9: Cells and Tissues
Activity 4 worksheet: Human genetics
This is a research activity. Find out as much as possible about some of these topics. You may get an
opportunity to talk with other students about what you have learned. Here are some ideas:
• HUGO the Human Genome project, which is aiming to find out the sequence of genes and the
characteristics that each genes code for.
• Genetic diseases such as cystic fibrosis, haemophilia and sickle cell anaemia.
• The genetic link with breast cancer.
• Genetic counselling.
Further activities
• Make up a factsheet on the components of a cell including nucleus and DNA - this can be used
for revision purposes.
• Ask your teacher for GCSE-type questions on genetic engineering and the use of cells for
producing medicines and materials.
• Interpret cell squashes in terms of the chromosomes (mitosis and meiosis).
© 2000 Channel Four Television Corporation
page 6 of 6