Key Idea 1: Living things are both similar to and different from each other and from nonliving things.

PERFORMANCE INDICATOR 1.1: Explain how diversity of populations within ecosystems relates to the stability of ecosystems.

MAJOR UNDERSTANDING 1.1b: An ecosystem is shaped by the nonliving environment as well as its interacting species. The world contains a wide diversity of physical conditions, which creates a variety of environments.

MAJOR UNDERSTANDING 1.1d: The interdependence of organisms in an established ecosystem often results in approximate stability over hundreds and thousands of years. For example, as one population increases, it is held in check by one or more environmental factors or another species.

MAJOR UNDERSTANDING 1.1f: Every population is linked, directly or indirectly, with many others in an ecosystem. Disruptions in the numbers and types of species and environmental changes can upset ecosystem stability.

Key Idea 6: Plants and animals depend on each other and their physical environment.

PERFORMANCE INDICATOR 6.1: Explain factors that limit growth of individuals and populations.

MAJOR UNDERSTANDING 6.1e: In any particular environment, the growth and survival of organisms depend on the physical conditions including light intensity, temperature range, mineral availability, soil/rock type, and relative acidity (pH).

PERFORMANCE INDICATOR 6.2: Explain the importance of preserving diversity of species and habitats.

MAJOR UNDERSTANDING 6.2a: As a result of evolutionary processes, there is a diversity of organisms and roles in ecosystems. This diversity of species increases the chance that at least some will survive in the face of large environmental changes. Biodiversity increases the stability of the ecosystem.

MAJOR UNDERSTANDING 6.2b: Biodiversity also ensures the availability of a rich variety of genetic material that may lead to future agricultural or medical discoveries with significant value to humankind. As diversity is lost, potential sources of these materials may be lost with it.

Key Idea 7: Human decisions and activities have had a profound impact on the physical and living environment.

PERFORMANCE INDICATOR 7.1: Describe the range of interrelationships of humans with the living and nonliving environment.

MAJOR UNDERSTANDING 7.1a: The Earth has finite resources; increasing human consumption of resources places stress on the natural processes that renew some resources and deplete those resources that cannot be renewed.

MAJOR UNDERSTANDING 7.1b: Natural ecosystems provide an array of basic processes that affect humans. Those processes include but are not limited to: maintenance of the quality of the atmosphere, generation of soils, control of the water cycle, removal of wastes, energy flow, and recycling of nutrients. Humans are changing many of these basic processes and the changes may be detrimental.

MAJOR UNDERSTANDING 7.1c: Human beings are part of the Earth’s ecosystems. Human activities can, deliberately or inadvertently, alter the equilibrium in ecosystems. Humans modify ecosystems as a result of population growth, consumption, and technology. Human destruction of habitats through direct harvesting, pollution, atmospheric changes, and other factors is threatening current global stability, and if not addressed, ecosystems may be irreversibly affected.

PERFORMANCE INDICATOR 7.2: Explain the impact of technological development and growth in the human population on the living and nonliving environment.

MAJOR UNDERSTANDING 7.2a: Human activities that degrade ecosystems result in a loss of diversity of the living and nonliving environment. For example, the influence of humans on other organisms occurs through land use and pollution. Land use decreases the space and resources available to other species, and pollution changes the chemical composition of air, soil, and water.

MAJOR UNDERSTANDING 7.2b: When humans alter ecosystems either by adding or removing specific organisms, serious consequences may result. For example, planting large expanses of one crop reduces the biodiversity of the area.

MAJOR UNDERSTANDING 7.2c: Industrialization brings an increased demand for and use of energy and other resources including fossil and nuclear fuels. This usage can have positive and negative effects on humans and ecosystems.

PERFORMANCE INDICATOR 7.3: Explain how individual choices and societal actions can contribute to improving the environment.

MAJOR UNDERSTANDING 7.3a: Societies must decide on proposals which involve the introduction of new technologies. Individuals need to make decisions which will assess risks, costs, benefits, and trade-offs.

MAJOR UNDERSTANDING 7.3b: The decisions of one generation both provide and limit the range of possibilities open to the next generation.

KEY IDEA 1: The central purpose of scientific inquiry is to develop explanations of natural phenomena in a continuing and creative process

PERFORMANCE INDICATOR 1.2: Hone ideas through reasoning, library research, and discussion with others, including experts

PERFORMANCE INDICATOR 1.3: Work towards reconciling competing explanations; clarify points of agreement and disagreement

Reading: Key Ideas and Details

Cite specific textual evidence to support analysis of science and technical texts, attending to the precise details of explanations or descriptions.

Reading: Key Ideas and Details

Determine the central ideas or conclusions of a text; trace the text’s explanation or depiction of a complex process, phenomenon, or concept; provide an accurate summary of the text.

Reading: Craft and Structure

Determine the meaning of symbols, key terms, and other domain-specific words and phrases as they are used in a specific scientific or technical context relevant to grades 9–10 texts and topics.

Reading: Integration of Knowledge and Ideas

Translate quantitative or technical information expressed in words in a text into visual form (e.g., a table or chart) and translate information expressed visually or mathematically (e.g., in an equation) into words.

Reading: Range of Reading and Level of Text Complexity

By the end of grade 10, read and comprehend science/technical texts in the grades 9–10 text complexity band independently and proficiently

Writing: Range of Writing

Write routinely over extended time frames (time for reflection and revision) and shorter time frames (a single sitting or a day or two) for a range of discipline-specific tasks, purposes, and audiences.