Fig. 2.22. Eyeless Ozark cavefish (Amblyopsis rosae)
Image courtesy of Dante Fenolio from the U.S. Fish and Wildlife Service
Table 2.2 lists the core ideas in Life Science, as well as the defining questions for each life science DCI. See the framework for more examples and grade band endpoints or the NGSS website for further information.
Core Idea | Defining Question |
---|---|
LS1: From Molecules to Organisms: Structures and Processes |
How do organisms live, grow, respond to their environment, and reproduce? |
LS1.A: Structure and Function | How do the structures of organisms enable life’s functions? |
LS1.B: Growth and Development of Organisms | How do organisms grow and develop? |
LS1.C: Organization for Matter and Energy Flow in Organisms | How do organisms obtain and use the matter and energy they need to live and grow? |
LS1.D: Information Processing | How do organisms detect, process, and use information about the environment? |
LS2: Ecosystems: Interactions, Energy, and Dynamics | How and why do organisms interact with their environment, and what are the effects of these interactions? |
LS2.A: Interdependent Relationships in Ecosystems | How do organisms interact with the living and nonliving environment to obtain matter and energy? |
LS2.B: Cycles of Matter and Energy Transfer in Ecosystems | How do matter and energy move through an ecosystem? |
LS2.C: Ecosystem Dynamics, Functioning, and Resilience | What happens to ecosystems when the environment changes? |
LS2.D: Social Interactions and Group Behavior | How do organisms interact in groups so as to benefit individuals? |
LS3: Heredity: Inheritance and Variation of Traits | How are characteristics of one generation passed to the next? How can individuals of the same species and even siblings have different characteristics? |
LS3.A: Inheritance of Traits | How are the characteristics of one generation related to the previous generation? |
LS3.B: Variation of Traits | Why do individuals of the same species vary in how they look, function, and behave? |
LS4: Biological Evolution: Unity and Diversity | How can there be so many similarities among organisms yet so many different kinds of plants, animals, and microorganisms? How does biodiversity affect humans? |
LS4.A: Evidence of Common Ancestry and Diversity | What evidence shows that different species are related? |
LS4.B: Natural Selection | How does genetic variation among organisms affect survival and reproduction? |
LS4.C: Adaptation | How does the environment influence populations of organisms over multiple generations? |
LS4.D: Biodiversity and Humans | What is biodiversity, how do humans affect it, and how does it affect humans? |
The life sciences focus on living organisms at scales from single molecules to large-scale interactions in the biosphere. Living organisms are parts of whole systems. The life sciences examine the relationships between organisms and their environments. Although there is a wide diversity of life on Earth, biologists and ecologists recognize that all organisms are related through evolutionary processes and ecological interactions. Hereditary processes drive evolution and are key to understanding life on Earth. The framework emphasizes that making sense of the unity and diversity of life on Earth is key to learning the life sciences.
Fig. 2.22. Eyeless Ozark cavefish (Amblyopsis rosae)
Image courtesy of Dante Fenolio from the U.S. Fish and Wildlife Service
Aquatic scientists study the wide range of life on Earth, with an emphasis on the organisms and processes that live and interact in the ocean, lakes, and rivers on Earth. For example, marine biologists study how some fish use ultraviolet light to communicate with other fish and how coral larvae settle in an area based on chemical cues. Marine botanists may examine how dissolved oxygen levels in different tidepools affect algae composition. Molecular biologists look at the relationship between how an organism reproduces and the gene flow between different populations. Evolutionary biologists describe cases of convergent evolution, for example fish of many different families living in dark caves have no pigments or functional eyes (Fig. 2.22).