Homework
Stem cells task
Stem cells are undifferentiated cells that can differentiate into specialised cells such as
nerve or muscle cells.
There are two types of stem cells:
Embryonic stem cells
Adult stem cells
Stem cells are currently used to treat cancers such as leukaemia. Other diseases that stem
cells may help include:
Parkinson's disease
Use jgrundy@edublogs.org to help
you
Stroke
Spinal cord injuries
Alzheimer's disease
Type I diabetes
Your task is to produce an information sheet (one A4 side only) to explain what stem cells
are and how they are used in medicine. You must include:
-A definition of stem cells
-A description of the 2 different types of stem cells
-A definition of therapeutic cloning
-A list of diseases that stem cells are currently used to treat and suggestions of future uses of
stem cells in medicine.
-A comment on some of the ethical issues involved in the use of stem cells.
Key words and definitions- sort them out!
DNA
Cell
Gene
Chromosome
Nucleus
The part of a cell that contains genetic
information.
Thread-like structures holding genes.
The chemical from which chromosomes
are made.
The basic building block of a living
organism.
A section of DNA controlling a
characteristic.
Mitosis
Learning Objective:
In order to be successful in this lesson you must be able to:
explain how asexual reproduction and mitosis are related.
Mitosis
state that body
cells divide by
mitosis for
growth and
repair.
draw simple
diagrams to
describe mitosis
PROGRESS
explain how asexual
reproduction and
mitosis are related.
Why do cells in the body need to
divide by mitosis?
Mitosis is the type of cell division that leads to
growth or repair. When a cell divides by
mitosis:
• two new cells form
• each cell is identical to the other one
http://www.bbc.co.uk/education/clips/zsd8q6f
1) chromosomes
duplicate or
make exact copies
of self
2. Nuclei
divide
How many times does the cell
divide?
How many daughter cells are
formed?
What can you say about those
daughter cells?
3. Identical
daughter cells
formed
Mitosis and asexual reproduction
In asexual reproduction, one individual produces offspring that are genetically
identical to itself. These offspring are produced by mitosis.
There are many invertebrates, including sea stars and sea anemones for
example, that produce by asexual reproduction.
Meiosis
Learning Objective:
In order to be successful in this lesson you must be able to:
Explain that the cell divides twice to form 4 gametes, each with as
single set of chromosomes
Meiosis
state that cells in
reproductive
organs divide to
produce
gametes
draw simple
diagrams to
describe meiosis
PROGRESS
Explain that the
cell divides twice
to form 4
gametes, each
with as single set
of chromosomes
Why do cells in the body need to
divide by meiosis?
Meiosis is the type of cell division that produces
gametes.
A human body cell contains 46 chromosomes arranged in 23 pairs. Human
gametes are haploid – so their nucleus only contains a single set of 23
unpaired chromosomes.
Meiosis
http://www.cellsalive.com/meiosis_js.htm
How many times does
the cell divide?
How many gametes are
formed?
What can you say about
those gametes?
Meiosis
produces four
genetically
different
haploid cells.
Unlike mitosis,
meiosis is a
reduction
division – the
chromosome
number is
halved from
diploid (46
chromosomes
in 23 pairs in
humans) to
haploid (23
chromosomes
in humans).
Comparing mitosis and meiosis
Comparing mitosis and meiosis