Students are learning to distinguish
and describe objects, in order to group them into larger groups. It is easy
for students to group inanimate objects because they group shape, color, or
size. Real organisms are not perfect and therefore, it is more difficult to
recognize similar characteristics within groups.
Living organisms have to consider more a
range of characteristics. For example, a cat could mean a house cat, a lion, a
tiger, or a bobcat. Each have a cat-like look but they are very different
animals. Almost all of the features have to be described. A nose, could be
large, small, flat, or pointed. The nose could have large nostrils or small
Young children need guidance is defining
the ranges and descriptions of each of these characteristics. It is also
important to emphasize is that scientists group organisms into assemblages
with similar characteristics. This practice makes it easy to distinguish and
compare various groups of similar organisms.
- Prior to lab you may want to make
playdough to be used during class. The recipe is as follows:
250 ml flour
125 ml salt
5 ml cream of tartar
250 ml water
about 1/2 ml food coloring about 1/2 ml oil
Cook, while stirring, over medium heat
until the gloppy mess looks like playdough. Knead briefly after the mixture
has cooled a little. You will need to multiply this recipe by 6 to get enough
for a class of 30 students, but it should be made in two batches. Large
amounts of dough are difficult to stir because the mixture becomes firm. Store
the playdough in a plastic bag or a margarine tub.
- Give groups of students a Wild Animal
Placemat to look at. Discuss each of the organism listed on the placemat. Note
that the name of "family" members is given in each box. For
instance, as the students the "family" of elephants. The father is a
bull, mother is a cow, baby is a calf, and a group is called a herd.