Junior Science Round 1
Teacher Material
Investigation of the variety of living things
Introduction
In these investigations there are three specific differences in the approach used, compared to more
traditional methods.
•
Students identify the plants and animals themselves rather than simply being told what they
are.
•
Through the use of keys students develop their powers of deductive reasoning, they learn about
the classification of living organisms based on the factors which identify them.
•
Students are required to make observations, and to make judgments based on these
observations. They will only proceed to the next step if their reasoning is correct. This
promotes logical patterns of thought.
The skill of using a key is central to the study of living things, and will be essential for any habitat
study. By working with plants and animals in this way, students may become more aware of their local
environment.
The revised primary school curriculum, introduced in September 2003, requires students from infants
to sixth class to study the variety of living things. They will learn how to design and use simple keys to
plants and animals. This material relates to OB38 and OB39 and it provides a foundation for the
ecology study in OB59 (Page 15 of the syllabus document).
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Junior Science Round 1
Teacher Material
Types of Biological keys
(a) Dichotomous Key using paired clues
The most common and simplest type of key to use is a dichotomous key, dichotomous meaning
‘branching in two’. By following the key and making the correct choices, you should be able to
identify a specimen. There is no apparent uniformity in presentation for dichotomous keys. An extract
from this type of key is shown here.
1
Bean is round ------------------------------- Garbanzo Bean
Bean is oval --------------------------------- Go to 2
2
Bean is white/green ------------------------ Northern Bean
Bean has dark colours ---------------------- Go to 3
(b) Dichotomous Key using branched pathways
This type of key uses a series of questions, the answers to which lead the student down branching
pathways. The questions are structured to allow the student to follow a simple "yes" or "no" path to the
next question. An extract from this type of key is pictured here.
Extract from Field Studies Council guide OP39 - see details in teacher resource list
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Junior Science Round 1
Teacher Material
Here are some rules to keep in mind when using keys.
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—
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Read both statements carefully. Decide which description fits the sample better.
Keep note of the steps taken. This will allow double-checking of the work.
If a student is unsure of which choice to make between a pair of statements, follow both (one at
a time). After working through the next pair of statements, it should become clear which path to
take.
—
Work with more than one sample if possible. This will allow the student to tell whether the
sample being looked at is typical. This is especially true when working with plants - examine
more than one leaf, branch, seed or flower.
—
When a sample is keyed out, do not take the first effort as the final result. It is always a good
idea to double-check the result.
Why do we need keys?
A class discussion is used to introduce the concept of using keys as an aid to the identification and
classification of living organisms. Various methodologies, such as questioning, brainstorming, ‘think,
pair, and share’, may be used to ascertain students' prior knowledge and skill level. These also promote
discussion within the class.
Student Material
Question 1 could bring out a great variety of answers - cattle, groceries, cars, CDs and, it is hoped,
living things.
Question 2 could have suggestions that sorting and classifying bring about order, save time, and make
it easier to find and name objects.
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Junior Science Round 1
Teacher Material
Investigation 1
How to use a key
Students are given a very short key to simple beans, and some bean samples. It may be necessary to
guide the students in identifying one of the beans. The students then proceed to identifying the other
samples. Using unfamiliar beans allows the students to concentrate on the process of following the
key.
A short class discussion at the end of the exercise asks the students which features they have looked at
in the beans in order to key them out. Using this key, students look at shape followed by colour.
The ‘best practice’ rules should be read with the students before they use the next key. A simple
interactive version of this key is available at www.juniorscience.ie.
Answer.
A
A= Northern bean (white bean)
B
E
B= Garbanzo bean (chickpea)
C= Pinto bean
D= Black Bean (turtle bean)
C
E= Kidney bean (chilli bean)
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Junior Science Round 1
Teacher Material
Investigation 2
Living Things - A simple guide to "Who's Who?"
Class Discussion
Students need to know how to differentiate between a plant and an animal and also between a
vertebrate and an invertebrate. Discussing questions and deciding on answers as a group could be used
to determine students' present capacity to do so, and to present some facts that they should know
before proceeding to further investigations. Students will bring all sorts of ideas to the discussion – it is
important at this stage to clarify misconceptions that students may have. Teacher-led discussion should
lead students to the facts that:
•
animals move around;
•
animals eat plants and other animals – they cannot make their own food;
•
plants do not move around;
•
plants are usually green – the presence of chlorophyll may be mentioned;
•
plants can make their own food.
Sorting Exercise
Students sort the living organisms into ‘plant’ and ‘animal’ groups, giving a reason for each decision.
They could work from the list in the worksheet, or use cards with images or names on them. The use of
coloured images of plants from magazines would reinforce the idea of the green colour in plants.
When asked if it is difficult to sort animals into vertebrate and invertebrate groups, most students will
probably answer ‘Yes’. Allowing them to discuss their difficulties at this stage may help them in later
investigations.
Vertebrate key
This can be done as group work, individual class exercise or homework.
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Junior Science Round 1
Teacher Material
Using games
This sorting exercise could be presented as a game in which each student becomes the plant or animal
represented on a card the teacher gives them. Ask those who consider themselves ‘plants’ to remain
seated and ‘animals’ to stand up. Those who are not sure should ask for help. Each can call out what
they are. This helps to avoid any mistakes in classification at this stage of the game. Then ask the
‘animals’ to migrate to one corner if they are vertebrate and another if they are ‘invertebrate’.
Check the accuracy of the groups as they have formed. Some organisms, like a snake or a lobster, may
cause confusion among students. It is important to clarify this before students return to the worksheet
to note their answers.
Sample image and name cards for photocopying are included at the end of the teacher material.
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Junior Science Round 1
Teacher Material
Investigation 3
Identifying invertebrates using a key
Students work through a key to simple invertebrates. Students may work with live samples, preserved
samples, plastic models, photocopied images or projected images.
Some students may need to be led through the key with an example and should then be able to key out
a range of organisms for themselves. The example of the common earwig (O’Connor and Ashe, Irish indoor
insects) is
keyed out here.
Pincer
Antenna
Leg
1
Legs?
No --------- Go to 2
Yes -------- Go to 5
Once the student sees the difference between antenna, pincers and legs, they are off to 5.
5
Six legs?
No --------- Go to 6
Yes -------- Insect
When the legs have been counted, the student has successfully keyed out the earwig as an insect!
The student notes also contain a simple key to trees. This very simple key will help students to identify
five common trees using the winter twig as the sample.
Éanna Ní Lamhna’s Transition Year book, ‘Be an Environmental Scientist’ contains an excellent
detailed key to common invertebrates. Links to excellent interactive websites for tree identification can
be found at www.juniorscience.ie.
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Junior Science Round 1
Teacher Material
Investigation 4
Identifying plants and animals in local habitats:
Each group needs:
•
a variety of plant and animal keys suitable for the local area;
•
a variety of suitable collecting equipment – pooter, bucket, specimen jars, plastic bags, forceps,
etc.;
•
a variety of suitable viewing equipment – nature viewers, bug viewers, magnifying glass, etc.
Each student needs:
•
suitable clothing;
•
clipboard, pencil;
•
copy of worksheets 1 and 2.
Teacher preparation
•
Give clear instruction to each group:
a. these are the limits of the area we work in today;
b. observe the variety of the living things you observe within the area;
c. return each organism to the habitat when finished identifying and drawing.
•
Set an appropriate time limit.
•
Either circulate among groups to help, or remain in a designated area so that students know
where to go to ask questions.
•
If there is a digital camera available, the students' activity can be recorded for display purposes,
and photographs taken of the living things observed in situ. It is particularly useful for
recording images of species not covered in the keys taken to the field, so that they can be later
identified in the lab.
Safety considerations
Teachers should follow appropriate safety procedures in carrying out the activities described in this
section.
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Junior Science Round 1
Teacher Material
Resource materials
1. Field Studies Council laminated Field Keys available by mail order from:
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IPCC, 119 Capel Street, Dublin 1, Tel: 01 8722397, www.ipcc.ie;
Field Studies Centre, Derrygonnelly, Co. Fermanagh, Tel: 048 68641675
(mail order payment in Stg. £ only);
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FSC Publications, Preston, Montford, Shrewesbury, SW41HW,
Tel: 0044 1743 852140, Fax: 0044 1743 852101
Email: publications@field-studies-council.org.
2. Nature viewers and ‘bug viewers’ are available from all scientific suppliers.
3. Beans from health food stores or most supermarkets (white beans may prove difficult to find
but can be replaced with flageolet beans).
4. Copyright-free teachers worksheets with excellent images of living things, and a variety of keys
are available at www.chatburnwildlife.org.uk.
Reference books
& Biokeys, Blackie Press, ISBN 0216924170
& John Kilbracken’s series of books ‘The Easy Way to Identify…’
Birds:
ISBN 0752300261
Flowers:
ISBN 0752300274
Trees:
ISBN 0752300288
(currently out of print but available in most Irish public libraries)
& Be an Environmental Scientist, Éanna Ní Lamhna, ISTA publications
& Irish Indoor Insects, A Popular Guide, O'Connor & Ashe, ISBN 1860590950
Online information
Links to useful websites may be found at www.juniorscience.ie.
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Junior Science Round 1
Teacher Material
Sorting Cards
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