Highlighted Phenomena from Discipline Specific Grade 7
- Scientists sometimes find isotopic traces of ocean biomass in inland forests (likely transported by bears who caught salmon returning upstream to spawn).
- Maps of the human genome show that about 10 percent of our genetic code matches the genetic code of specific viruses.
- All living organisms have cells that use the same basic structure made out of the same basic materials.
- The diet of the person’s mother while she was pregnant may affect the age that person eventually starts puberty.
- During El Niño years, large numbers of sea lion pups have been showing up malnourished and abandoned by their parents on the beaches in Southern California.
Introduction to Discipline Specific Grade 7
The framework presents life science as “systems within systems within systems” in which cells interact to create body systems which interact to create organisms which interact to create ecosystems. The example instructional sequence in the Discipline Specific grade seven begins at the tangible, macroscopic scale of ecosystems, zooms into the level of cells, and then zooms back out again to revisit ecosystems. The section is rich with example phenomena that illustrate important interactions at each scale.
Students begin by describing the interactions between organisms within an ecosystem in IS1 (Interdependent Ecosystems). A snapshot illustrates how students, after reading an informational text about wolverines, can create a food web as a systems model and then predict the effects of human behavior on this system.
Instructional segment 2 (Photosynthesis and Respiration) focuses on two of the most important mechanisms by which matter cycles through ecosystems—the chemical processes of photosynthesis and respiration. A snapshot shows how students develop physical models of these chemical reactions to explain how matter moves from one organism to another.
In IS3 (Cells and Body Systems), students examine where these chemical reactions happen within individual organisms—within the microscopic system of a cell and by interactions between those cells. Systems thinking allows students to predict the impacts of changes to a system. A vignette asks students, What happens when one system breaks down within the human body? and illustrates how teachers can help students develop their systems thinking enough to construct explanations of the consequences.
In IS4 (Evidence of Evolution), students ask and answer questions about how different organisms have similar body systems but vary slightly in body structures. Students then explain the mechanisms that cause this phenomenon during the next several instructional segments. A snapshot in IS5 (Inheritance and Genetics) shows how students can obtain information from an interactive computer lesson to create systems models illustrating how parents pass on their genetic code to offspring in sexual and asexual reproduction. They then examine the arguments in favor of and against genetically modified food in order to develop a model for how genetic code can be modified at human timescales through tangible interventions. Students analyze data in IS6 (Natural Selection) to see how similar modifications occur naturally over much longer timescales. Instructional segment 6 includes a series of snapshots that illustrate how teachers can scaffold instruction to help students analyze different population data and relate it to environmental conditions. Students track how sardine and anchovy populations change in response to El Niño conditions and how organisms, such as moose in Norway and pygmies in the tropics, have body sizes that are well adapted for heat retention in their local climate.
Grade seven culminates in IS7 (Revisiting Ecosystems) with students returning to the ecosystem scale. They apply their understanding of natural changes to predict the effects of rapid changes due to human activities. Students define problems that may result from human activities and design solutions that minimize these impacts. Solutions can be very local and practical, such as the engineering connection in which students design and optimize a compost system to reduce the waste from their school cafeteria.
from d’Alessio, Matthew A. (2018). Executive Summary: Science Framework for California Public Schools: Kindergarten Through Grade Twelve. Sacramento: Consortium for the Implementation of the Common Core State Standards.