Weston Middle School
Life Science Course Materials
from the Massachusetts
Curriculum frameworks (2001)
Life Science (Biology)
Science may be described as the attempt to give good accounts of the patterns in nature. The result of scientific investigation is an understanding of natural processes. Scientific explanations are always subject to change in the face of new evidence. Ideas with the most durable explanatory power become established theories or are codified as laws of nature.
Overall, the key criterion of science is that it provide a clear, rational, and succinct account of a pattern in nature. This account must be based on data gathering and analysis and other evidence obtained through direct observations or experiments, reflect inferences that are broadly shared and communicated, and be accompanied by a model that offers a naturalistic explanation expressed in conceptual, mathematical, and/or mechanical terms....
Inquiry,
Experimentation, and Design
in the Classroom
Inquiry-Based Instruction
Engaging students in inquiry-based instruction is one way of developing conceptual understanding, content knowledge, and scientific skills. Scientific inquiry as a means to understand the natural and human-made worlds requires the application of content knowledge through the use of scientific skills. Students should have curricular opportunities to learn about and understand science and technology/engineering through participatory activities, particularly laboratory, fieldwork, and design challenges.
Inquiry, experimentation, and design should not be taught or tested as separate, stand-alone skills. Rather, opportunities for inquiry, experimentation, and design should arise within a well-planned curriculum. Instruction and assessment should include examples drawn from life science, physical science, earth and space science, and technology/engineering standards. Doing so will make clear to students that what is known does not stand separate from how it is known.
Asking Questions
Asking questions and pursuing answers are keys to learning in all academic disciplines. In the science classroom, one way students can do this is by exploring scientific phenomena in a classroom laboratory or an investigation around the school. Investigation and experimentation build essential scientific skills such as observing, measuring, replicating experiments, manipulating equipment, and collecting and reporting data. Students may choose what phenomenon to study or conduct investigations and experiments that are selected and guided by the teacher.
Students can also examine questions pursued by scientists in previous investigations of natural phenomena and processes, as reported or shown in textbooks, papers, videos, the Internet, and other media. These sources are valuable because they efficiently organize and highlight key concepts and supporting evidence that characterize the most important work in science. Such study can then be supported in the classroom by demonstrations, experiments, or simulations that deliberately manage features of a natural object or process. Whatever the instructional approach, science instruction should include both concrete and manipulable materials, along with explanatory diagrams and texts.
Investigations
An inquiry-based approach to science education also engages students in hands-on investigations that allow them to draw upon their prior knowledge and build new understandings and skills. Hands-on experiences should always be purposeful activities that are consistent with current research on how people learn and that develop student understanding of science concepts. Students should also have multiple opportunities to share, present, review, and critique scientific information or findings with others.
The characteristics of investigations develop through the different grade spans:
• In grades PreK–2, scientific investigations can center on student questions, observations, and communication about what they observe. For example, students might plant a bean seed following simple directions written on a chart. Then they can write down what happens over time in their own words.
• In grades 3–5, students can plan and carry out investigations as a class, in small groups, or independently, often over a period of several class lessons. The teacher should first model the process of selecting a question that can be answered, formulating a hypothesis, planning the steps of an experiment, and determining the most objective way to test the hypothesis. Students should incorporate mathematical skills of measuring and graphing to communicate their findings.
• In grades 6–8, teacher guidance remains important but allows for more variation in student approach. Students at this level are ready to formalize their understanding of what an experiment requires by controlling variables to ensure a fair test. Their work becomes more quantitative, and they learn the importance of carrying out several measurements to minimize sources of error. Because students at this level use a greater range of tools and equipment, they must learn safe laboratory practices (see Appendix IV). At the conclusion of their investigations, students in these grades can be expected to prepare reports of their questions, procedures, and conclusions.....
Life Science Frameworks
The life sciences investigate the diversity, complexity, and interconnectedness of life on earth. Students are naturally drawn to examine living things, and as they progress through the grade levels, they become capable of understanding the theories and models that scientists use to explain observations of nature. In this respect, a PreK–12 life science curriculum mirrors the way in which the science of biology has evolved from observation to classification to theory.
By high school, students learn the importance of Darwin’s theory of evolution as a framework for explaining continuity, diversity, and change over time.
Students emerge from an education in the life sciences recognizing that order in natural systems arises in accord with rules that seem to govern the physical world, and can be modeled and predicted through the use of mathematics....
.... In grades 6–8, the emphasis changes from observation and description of individual organisms to the development of a more connected view of biological systems. Students in these grades begin to study biology at the microscopic level, without delving into the biochemistry of cells. They learn that organisms are composed of cells and that some organisms are unicellular and must therefore carry out all of the necessary processes for life within that single cell.
Other organisms, including human beings, are multicellular, with cells working together. Students should observe that the cells of a multicellular organism can be physically very different from each other, and should relate that fact to the specific role that each cell has in the organism (specialization). For example, cells of the eye or the skin or the tongue look different and do different things. Students in these grades also examine the hierarchical organization of multicellular organisms and the roles and relationships that organisms occupy in an ecosystem.
As is outlined in the National Science Education Standards, students in grades 6–8 should be exposed in a general way to the systems of the human body, but are not expected to develop a detailed understanding at this grade level. They should develop the understanding that the human body has organs, each of which has a specific function of its own, and that these organs together create systems that interact with each other to maintain life.
At the macroscopic level, students focus on the interactions that occur within ecosystems. They explore the interdependence of living things, specifically the dependence of life on photosynthetic organisms such as plants, which in turn depend upon the sun as their source of energy.
Students use mathematics to calculate rates of growth, derive averages and ranges, and represent data graphically to describe and interpret ecological concepts.
Learning standards for grades 6–8 fall under the following eight subtopics:
- Classification of Organisms;
- Structure and Function of Cells;
- Systems in Living Things;
- Reproduction and Heredity;
- Evolution and Biodiversity;
- Living Things and Their Environment;
- Energy and Living Things; and Changes in Ecosystems Over Time.
LEARNING STANDARDS
Classification of Organisms
1. Classify organisms into the currently recognized kingdoms according to characteristics that they share. Be familiar with organisms from each kingdom.
Structure and Function of Cells
2. Recognize that all organisms are composed of cells, and that many organisms are single-celled (unicellular), e.g., bacteria, yeast. In these single-celled organisms, one cell must carry out all of the basic functions of life. Observe, describe, record, and compare a variety of unicellular organisms found in aquatic ecosystems.
3. Compare and contrast plant and animal cells, including major organelles (cell membrane, cell wall, nucleus, cytoplasm, chloroplasts, mitochondria, vacuoles). Observe a range of plant and animal cells to identify the cell wall, cell membrane, chloroplasts, vacuoles, nucleus, and cytoplasm when present.
4. Recognize that within cells, many of the basic functions of organisms (e.g., extracting energy from food and getting rid of waste) are carried out. The way in which cells function is similar in all living organisms.
Systems in Living Things
5. Describe the hierarchical organization of multicellular organisms from
cells to tissues to organs to systems to organisms.
6. Identify the general functions of the major systems of the human body (digestion, respiration, reproduction, circulation, excretion, protection from disease, and movement, control, and coordination) and describe ways that these systems interact with each other.
7. Recognize that every organism requires a set of instructions that specifies its traits. These instructions are stored in the organism’s chromosomes.Heredity is the passage of these instructions from one generation to another.
8 . Recognize that hereditary information is contained in genes located in the chromosomes of each cell. A human cell contains about 30,000 different genes on 23 different chromosomes.
9 . Compare sexual
reproduction (offspring inherit half of their genes from each parent)
with asexual reproduction (offspring is an identical copy of the parent’s
cell).
Evolution and Biodiversity
10 . Give examples of ways in which genetic variation and environmental
factors are causes of evolution and the diversity of organisms.
11 . Recognize that evidence drawn from geology, fossils, and comparative anatomy provides the basis of the theory of evolution.
12 . Relate the extinction of species to a mismatch of adaptation and the environment.
Living Things and Their Environment
13. Give examples
of ways in which organisms interact and have different functions within
an ecosystem that enable the ecosystem to survive. Study several symbiotic
relationships such as oxpecker (bird) with rhinoceros (mammal). Identify
specific benefits received by one or both partners.
Energy and Living Things
14. Explain the roles and relationships among producers, consumers, and decomposers in the process of energy transfer in a food web. Distribute pictures of various producers, consumers, and decomposers to groups of students. Have each group organize the pictures according to the relationships among the pictured species and write a paragraph that explains the roles and relationships.
15. Explain how dead plants and animals are broken down by other living organisms and how this process contributes to the system as a whole. Observe decomposer organisms in a compost heap on the school grounds, a compost column in a plastic bottle, or a worm bin. Use compost for starting seeds in the classroom or in a schoolyard garden.
16. Recognize that producers (plants that contain chlorophyll) use the energy from sunlight to make sugars from carbon dioxide and water through a process called photosynthesis. This food can be used immediately, stored for later use, or used by other organisms. Test for sugars and starch in plant leaves.
Changes in Ecosystems Over Time
17. Identify ways in which ecosystems have changed throughout geologic time in response to physical conditions, interactions among organisms, and the actions of humans. Describe how changes may be catastrophes such as volcanic eruptions or ice storms. Study changes in an area of the schoolyard or a local ecosystem over an extended period. Students might even compare their observations to those made by students in previous years.
18. Recognize that
biological evolution accounts for the diversity of species developed through
gradual processes over many generations.
Links
geDNA
Simulation Activity2