Introduction
Slide 4.1
5 minutes
Show Slide 4.1 and outline the objectives for the session.
Slide 4.1
Objectives
• To provide a teaching strategy for identifying and correcting pupils’
misconceptions on cells
• To establish the importance of models in the teaching of cells
Remind participants of the misconceptions they identified in Session 1 relating
to cells.
Identifying pupils’ ideas on cells
15 minutes
Say that the following task illustrates a technique that can be used to determine
pupils’ ideas on cells.
Task F
Slide 4.2
15 minutes
Show Slide 4.2.
Slide 4.2
‘The four Ws’
Where?
When?
Cells
Why?
What?
Ask participants, working in groups, to write a question they could ask pupils
for each of the four Ws.
After 5 minutes ask the groups in turn to share their questions. Ask which
misconception on cells the questions could be used to find.
Make the point that it is important that teachers think about the key questions
they might ask pupils in advance and note them down in their lesson plans.
Skilful questioning needs planning.
Additional guidance
This activity can be used as a starter activity with pupils. Get the pupils to fold a
piece of paper into four. Put the key word in the centre and write the question
they want answering in each quarter.
Using models to teach about cells
Handout 4.3
10 minutes
Give out Handout 4.3.
Use it to explain how participants can use models to teach cells.
32 | Misconceptions in Key Stage 3 science | notes for course tutors
© Crown copyright 2002
Make the following points:
• The QCA scheme of work invites teachers to use models to teach cells, such
as in Units 7A and 8A.
• Research has shown that the choice of materials in making model cells is
important and can lead to misconceptions. For instance, the use of wallpaper
paste in animal cell models can contain air bubbles. These bubbles have
subsequently been drawn by pupils who think that all cells contain them
(vacuoles in plant cells are not randomly generated like air bubbles). It is important
for teachers to discuss with pupils what each part of the model represents.
• It is equally important to discuss the strengths and weaknesses of the model;
this is something that is not always done – you might like to stress the
importance of this.
• Cells will be a new area of the curriculum for pupils at Key Stage 3; they often
have difficulty recognising that animals and plants are multicellular organisms
and that cells are three-dimensional.
• Many teachers introduce cells using three-dimensional models. The QCA
scheme of work does this in Unit 7A.
• Research has shown that if this modelling of cells is continued, so that pupils
model specialised cells and build tissue and organs from model cells, they
make even better progress.
Slide 4.4
Use Slides 4.4, 4.5 and 4.6 to show some models that pupils have made.
Slide 4.5
Slide 4.6
Models of typical animal and plant cell
33 | Misconceptions in Key Stage 3 science | notes for course tutors
Slide 4.4
© Crown copyright 2002
Slide 4.5
Specialised cells – pupils’ models
Spermatozoa
Cells arranged as tissue in a tank
Handout 4.7
Nerve Cell
Slide 4.6
Refer participants to Handout 4.7.
Say that:
• When teaching cells we can adopt a similar approach to that of teaching
particles, by increasing the sophistication of the teaching model step by
step.
Additional guidance
It would be useful if you had some model cells prepared to demonstrate what
can be produced. Unfortunately there is no time available in this unit to allow
participants to make their own, but by having some already made you could
provide useful examples of how they could do this in their own schools. A
model of many cells forming a model tissue could also be demonstrated.
34 | Misconceptions in Key Stage 3 science | notes for course tutors
© Crown copyright 2002
Reference
Models and modelling project 2001
(Hampshire LEA, Southampton LEA and the University of Reading)
Plenary
Slide 4.8
5 minutes
Remind participants of the objectives for the session. Show Slide 4.8 which
describes the anticipated outcomes relating to the objectives.
Slide 4.8
Plenary for Session 4
By the end of this session participants should:
• have had the opportunity to carry out a strategy to determine pupils’ understanding of
cells;
• be aware of an approach they could use to teach cells using models;
• be developing an understanding of a ‘good enough’ approach to using models to
teach cells.
Invite any further questions and points participants might like to make, and
encourage them to complete the evaluation form for Session 4. Tell them that
now is a good time to note any points which they want to follow up in school.
35 | Misconceptions in Key Stage 3 science | notes for course tutors
© Crown copyright 2002
An approach to teaching
cells using models
Handout 4.3
• Build three-dimensional models of typical plant and animal cells
• Discuss what each part represents, developing specific
language
• Discuss strengths and weaknesses of any model and how
each may be improved
• Ask pupils to build their own models of specialised cells,
identifying any strengths and weakness
• Build a model tissue from model cells as a class
• Relate the model to what is seen through a microscope
• Consider how you might construct some model organs from
model tissue, e.g. leaf, heart, eye
36 | Misconceptions in Key Stage 3 science | notes for course tutors
© Crown copyright 2002
Developing a sequence of
‘good enough’ cell models
Handout 4.7
Scientific idea
Teaching model
Can be used to
explain
The cell is the basic
building block of living
material, consisting of
nucleus, cytoplasm
and membrane
Plastic bag filled with
water or jelly and a
table tennis ball
All living things have
similar structures
Plant cells also have a
cell wall and vacuole
Plastic bag filled with
wallpaper paste
(shows vacuole)
placed in jar (shows
cell wall)
Differences between
plant and animal cells
Cells are adapted to
their function and have
specialised forms
Different materials can
be used to show how
cells are specialised
and adapted to their
function such as
balloons for guard
cells, football for egg
and marble with tail for
sperm (to show
relative size)
Differences in cell form
reflect their functions
Tissue is composed of
groups of the same
type of cells and
different tissues can
form organs
Plastic bag cells
placed in fish tank to
show tissue; compare
this with looking down
the microscope to see
layers
Tissue under the
microscope contains
many cells that are the
same
The cell membrane is
differentially
permeable
Visking tubing and
particle-sieve models
Gas exchange in the
lungs, respiration,
digestion, water
uptake in root hair,
photosynthesis
Nucleus contains
genetic material and
can divide causing cell
division
Nucleus made of
jumble of pipe
cleaners, animations
Reproduction and
growth
37 | Misconceptions in Key Stage 3 science | notes for course tutors
© Crown copyright 2002