Level4/Nat4 Biology
Lesson 7
Producing new cells
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• Learning Intentions
• I understand cell division and its role in growth and repair
in living organisms
• Success Criteria
• I can state that cell division is essential to allow
organisms to grow and repair damaged parts
• I understand that during cell division the parent cell
divides to produce two (genetically) identical cells.
• I can state that the two new cells contain the same
number of chromosomes in their nuclei as the parent cell
• I can state that cancer is uncontrolled cell division.
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• Where do cells come from?
• When does the body need to produce
new cells?
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When does the body need to produce new cells?
Think of the following situations…..
growth
Your body loses cells and cells are constantly dying but
your skin doesn’t disappear and you don’t get smaller.
repair
You cut your finger. The wound is eventually healed and
weeks later you cannot even see where the cut used to be.
reproduction
Your body can make sex cells. In humans, these cells are
sperm or egg cells. These cells contain the same genetic
information that can be found in other body cells.
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How does the body produce new cells?
The body needs to produce new cells for three main reasons:
● growth
● repair
● reproduction
How does it produce these cells?
The body is constantly producing new cells from old cells
dividing. This is called cell division.
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Where do cells come from?
Cell division occurs extremely quickly and each new cell
is also able to divide.
Cell division makes it possible for the body to:
 grow quickly;
 repair cuts and replace dead cells quickly;
 produce an enormous number of reproductive cells.
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Where do cells come from?
New cells are produced by cell division,
but this doesn’t mean that cells split in half.
What would be the problem if cells
did split in half to produce new cells ?
There wouldn’t be much of the cells left!
What actually happens is that cells have to make new
copies of the material inside them, as well as new
membranes before they divide.
Just before a cell divides, it appears to grow slightly as it
reproduces everything inside itself.
The nucleus doubles in size and then divides into two
equal halves.
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Cell division
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• The role of cell division in living organisms
Activity 1
•watch the power point ‘cell growth and reproduction’
•watch the DVD ‘mitosis’ and A GREAT Mitosis Video - YouTube
•complete page 13 of your summary sheet.
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• Activity 2
• In your notebook copy down the headings below.
• Leave a space under each heading.
• Look at the power point on cell division.
• Record the information from each slide in your own way
to show how cell division (mitosis) is involved in each
process.
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Repair of tissue (cuts)
Growth and development in animals
Growth and development in plants
Bacteria reproducing
Tissue culture
Regeneration in starfish
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Blood clotting
Now write a short note
on the role of cell
division
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Fertilization and implantation
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Fertilisation
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Cuttings
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Phototropism Phototropism in Tomatoes - Timelapse - YouTube
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Bacteria Replication
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Cloning using tissue culture
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regeneration
Sea Star Regeneration – YouTube
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Self Evaluation: I have
learned……….
Role of cell division
Root growth
in plants
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Self Evaluation: I have learned……….
• Learning Intentions
• I understand cell division and its role in growth and repair
in living organisms
• Success Criteria
• I can state that cell division is essential to allow
organisms to grow and repair damaged parts
• I understand that during cell division the parent cell
divides to produce two (genetically) identical cells.
• I can state that the two new cells contain the same
number of chromosomes in their nuclei as the parent cell
• I can state that cancer is uncontrolled cell division.
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