Life has an astounding variety of forms and occupies a diverse range of habitats. Yet all life shares common characteristics. The structure of DNA, the ability to respond to environmental stimuli, and the existence of a finite lifespan are common to all living organisms. In this unit, students consider the characteristics shared by all living things and how organisms acquire their basic needs from their environment.
When students see or use the word 'environment', we want them to regard all aspects of their surroundings, supportive to life and not, rather than associate a negative connotation - pollution, habitat loss and so on - with the word. Their environment is inside the classroom, just outside the classroom door, and in the schoolyard. It's the yards at home and the open fields and ditches where they can explore. Students should have the opportunity to investigate the life and the life-support system which surrounds them.
This unit establishes a foundation for the consideration of adaptation and succession in a grade 8 unit. The discussion of the consequences of environmental change caused by urbanization and by the agriculture and forestry industries in grade 9 is also based on an understanding of the characteristics and needs of living organisms.
Integrating the study of this unit with the optional unit Microorganisms is strongly recommended.
The study of microorganisms can serve as an engaging introduction to the question "What is life?".
Science writing and reading activities, as discussed in this Guide, should be incorporated into each lesson. Writing in personal, reflective journals, reading from newspapers, and reporting on the activities of science class in a variety of ways are only three strategies through which students may refine their understanding of the concepts of science and develop their ability to communicate through the written word.
Science challenge, as described in this Guide, is meant to extend students' critical and creative thinking abilities in the context of the science concepts being studied. Activities involving science challenge should be incorporated into science lessons in each unit. A good way to generate ideas for such activities is to have students brainstorm every thing they know about a particular topic and then generate questions which arise from what they know, or from gaps in their knowledge.
The challenge is intended to give each student a chance to investigate an area of interest in more depth than would be possible for all students in a class to do. Science challenge is a key strategy for bringing the Adaptive Dimension to the classroom, and for encouraging independent learning.
Note: Many of the resources listed in Science: An Information Bulletin for the Middle Level - Key Resource Correlations describe activities or ideas for activities.
Then, in groups of four, brainstorm a list of characteristics of living things. Once the list is complete, examine it and consider each characteristic. Try to identify organisms which are exceptions to the characteristic under consideration. Try to identify nonliving things (pebbles or water, for example) which fit the characteristic. For each anomaly identified, decide whether the characteristic should be struck from the list or revised to restate the principle.
Compile a class list of characteristics which have made it through the screening process. Repeat the screening procedure as a class group to produce a final list. Compare this class-produced list to a list from a text or other source. Discuss the similarities and the differences.
Objectives: 1.1, 1.2, 1.3, 1.5, 3.2, 4.3, 4.4
Assessment Techniques: individual anecdotal records, self- and peer-assessment checklists, self-assessment journal entries
Instructional Methods: brainstorming, problem solving, reflective discussion
Extension: "I am a rabbit. I have lived in a cage in
the classroom since September. I hear the students talking
about setting me free so that I can live in a natural
environment." What would this mean to the rabbit if the
rabbit was domesticated? wild?
Factors: B1, B2, C3,
C6, C15,
D3, F4,
F6
Objectives: 1.4, 2.2,
2.5, 2.8, 3.3, 3.4, 4.1, 4.4
Assessment Techniques: written presentation, oral
presentation with self- or peer assessment
Intructional Methods: focussed imaging, concept
formation
Assessment Techniques: rating scale, portfolio
entry,
presentation
Instuctional Method: interviewing
Instructions for creating and caring for animal communities
and individuals in the classroom can be found in
Cockroaches and Things (Murawsky, Bandurka, 1982
BB#
6086).
Back in the classroom, divide the leaves into as many
groups
as there are working groups. Ask each working group to list
all the similarities and all the differences of the set of
leaves which they have. Ask them to select one leaf and
produce a magazine add which 'sells' the leaf on the basis
of its appearance and function. Ask each group to present
its advertisement to the rest of the class. Discuss the
various functions of leaves which are promoted in the
advertisements.
How is a tree like a grass plant? How is it
different?
How is a tree like a human? How is it different?
How is a tree like a rock? How is it different?
Discuss responses with the class. Clarify their concept of
what life is and the diversity of life through the
discussions of the responses. Extend this activity using
ideas from Planning Adventures: Synectics from the
Saskatchewan Professional Development Unit and Saskatchewan
Instructional Development and Research Unit.
Pooters were described by Dan Stoker in an outdoor activity
book Monsters and Minibeasts. Materials needed are
two drinking straws, one of slightly smaller diameter than
the other, and a 2 cm square of panty hose material.
Take the square of material, put it over one end of the
straw
with the smaller diameter and slide the combination into one end
of the larger straw. Insert it far enough so that the corners of
the square of material just protrude. Wrap the joint between the
two straws with a piece of masking tape. Hold the pooter to the
light to see if the square of material is in place to act as a
filter. Insects can be drawn into the larger bottom straw by
sucking on the small straw.
Project WILD activity "Owl Pellets" discusses the classroom
use of pellets. Boreal Laboratories carries an owl pellet
kit, catalogue #69831-01.