Virginia

Virginia flag
Skills available for Virginia seventh-grade science standards

Standards are in black and IXL science skills are in dark green. Hold your mouse over the name of a skill to view a sample question. Click on the name of a skill to practice that skill.

Show alignments for:

Actions

LS.1 The student will demonstrate an understanding of scientific reasoning, logic, and the nature of science by planning and conducting investigations in which a) data are organized into tables showing repeated trials and means; b) a classification system is developed based on multiple attributes; c) triple beam and electronic balances, thermometers, metric rulers, graduated cylinders, and probeware are used to gather data; d) models and simulations are constructed and used to illustrate and explain phenomena; e) sources of experimental error are identified; f) dependent variables, independent variables, and constants are identified; g) variables are controlled to test hypotheses and trials are repeated; h) data are organized, communicated through graphical representation, interpreted, and used to make predictions; i) patterns are identified in data and are interpreted and evaluated; and j) current applications are used to reinforce life science concepts.

LS.2 The student will investigate and understand that all living things are composed of cells. Key concepts include a) cell structure and organelles; b) similarities and differences between plant and animal cells; c) development of cell theory; and d) cell division.

LS.3 The student will investigate and understand that living things show patterns of cellular organization. Key concepts include a) cells, tissues, organs, and systems; and b) patterns of cellular organization and their relationship to life processes in living things.

LS.4 The student will investigate and understand how organisms can be classified. Key concepts include a) the distinguishing characteristics of domains of organisms; b) the distinguishing characteristics of kingdoms of organisms; c) the distinguishing characteristics of major animal phyla and plant divisions; and d) the characteristics that define a species.

  • Information about physical features and activities is arranged in a hierarchy of increasing specificity. The levels in the accepted hierarchy include domain, kingdom, phylum, class, order, family, genus and species.

  • Current classification systems now generally recognize the categorization of organisms into three domains, Archaea, Bacteria and Eukarya.

  • As living things are constantly being investigated, new attributes (physical and chemical) are revealed that affect how organisms are placed in a standard classification system. This system is the basis for scientific binomial nomenclature.

  • Any grouping of organisms into domains or kingdoms is based on several factors, including the presence or absence of cellular structures, such as the nucleus, mitochondria, or a cell wall; whether the organisms exist as single cells or are multicellular; and how the organisms get their food. For example, simple, single-celled organisms that are able to survive in extreme environments are believed to be fundamentally different from other organisms and may be classified in their own domain (Archaea). Four different kingdoms of the Eukarya domain of organisms are generally recognized by scientists today (Protista, Fungi, Plants, and Animals).

  • Some important animal groups (phyla) are the cnidarians, mollusks, annelids, arthropods, echinoderms, and chordates.

  • Four important plant groups (divisions) are the mosses, ferns, conifers, and flowering plants.

  • A group of similar-looking organisms that can interbreed under natural conditions and produce offspring that are capable of reproduction defines a species.

  • classify organisms based on a comparison of key physical features and activities.

  • arrange organisms in a hierarchy according to similarities and differences in features.

  • categorize examples of organisms as representative of the three domains (Archaea, Bacteria and Eukarya) and recognize that the number of domains is subject to change as new data are collected.

  • categorize examples of organisms as representative of the kingdoms and recognize that the number of kingdoms is subject to change as new data are collected.

  • recognize examples of major animal phyla.

  • recognize examples of major plant divisions.

  • recognize scientific names as part of a binomial nomenclature.

LS.5 The student will investigate and understand the basic physical and chemical processes of photosynthesis and its importance to plant and animal life. Key concepts include a) energy transfer between sunlight and chlorophyll; b) transformation of water and carbon dioxide into sugar and oxygen; and c) photosynthesis as the foundation of virtually all food webs.

LS.6 The student will investigate and understand that organisms within an ecosystem are dependent on one another and on nonliving components of the environment. Key concepts include a) the carbon, water, and nitrogen cycles; b) interactions resulting in a flow of energy and matter throughout the system; c) complex relationships within terrestrial, freshwater, and marine ecosystems; and d) energy flow in food webs and energy pyramids.

LS.7 The student will investigate and understand that interactions exist among members of a population. Key concepts include a) competition, cooperation, social hierarchy, territorial imperative; and b) influence of behavior on a population.

LS.8 The student will investigate and understand interactions among populations in a biological community. Key concepts include a) the relationships among producers, consumers, and decomposers in food webs; b) the relationship between predators and prey; c) competition and cooperation; d) symbiotic relationships; and e) niches.

  • Organisms or populations that rely on each other for basic needs form interdependent communities.

  • Energy resources of a community are shared through the interactions of producers, consumers, and decomposers.

  • The interaction between a consumer that hunts for another consumer for food is the predator-prey relationship.

  • In a community, populations interact with other populations by exhibiting a variety of behaviors that aid in the survival of the population.

  • Organisms may exist as members of a population; populations interact with other populations in a community.

  • Populations of one species may compete with populations of other species for resources. Populations of one species may also cooperate with populations of other species for resources.

  • A symbiotic relationship may exist between two or more organisms of different species when they live and work together.

  • Symbiotic relationships include mutualism (in which both organisms benefit), commensalism (in which one organism benefits and the other is unaffected), and parasitism (in which one organism benefits and the other is harmed).

  • Each organism fills a specific role or niche in its community.

  • identify the populations of producers, consumers, and decomposers and describe the roles they play in their communities.

  • interpret, analyze, and evaluate data from systematic studies and experiments concerning the interactions of populations in an ecosystem.

  • predict the effect of population changes on the food web of a community.

  • generate predictions based on graphically represented data of predator-prey populations.

  • generate predictions based on graphically represented data of competition and cooperation between populations.

  • differentiate between the types of symbiosis and explain examples of each.

  • infer the niche of organisms from their physical characteristics.

  • design an investigation from a testable question related to interactions among populations. The investigation may be a complete experimental design or may focus on systematic observation, description, measurement, and/or data collection and analysis.

LS.9 The student will investigate and understand how organisms adapt to biotic and abiotic factors in an ecosystem. Key concepts include a) differences between ecosystems and biomes; b) characteristics of land, marine, and freshwater ecosystems; and c) adaptations that enable organisms to survive within a specific ecosystem.

LS.10 The student will investigate and understand that ecosystems, communities, populations, and organisms are dynamic, change over time, and respond to daily, seasonal, and long-term changes in their environment. Key concepts include a) phototropism, hibernation, and dormancy; b) factors that increase or decrease population size; and c) eutrophication, climate changes, and catastrophic disturbances.

  • Organisms may exist as members of a population; populations interact with other populations in a community; and communities together with the physical environment form ecosystems.

  • Changes that affect organisms over time may be daily, seasonal, or long term.

  • Plants may respond to light by growing toward it or away from it, a behavior known as phototropism.

  • Animals may respond to cold conditions with a period of lowered metabolism, a behavior known as hibernation.

  • Organisms may respond to adverse conditions with a period of lowered or suspended metabolism, a behavior known as dormancy.

  • A variety of environmental factors may cause the size of a population to increase or decrease. (This requires students to brainstorm examples of factors and predict the possible effects.)

  • Long-term changes may affect entire communities and ecosystems. Such large-scale changes include the addition of excess nutrients to the system (eutrophication), which alters environmental balance; dramatic changes in climate; and catastrophic events, such as fire, drought, flood, and earthquakes.

  • relate the responses of organisms to daily, seasonal, or long-term events.

  • differentiate between ecosystems, communities, populations, and organisms.

  • predict the effect of climate change on ecosystems, communities, populations, and organisms.

  • predict the effect of eutrophication on ecosystems, communities, populations, and organisms.

  • compare and contrast the factors that increase or decrease population size.

  • classify the various types of changes that occur over time in ecosystems, communities, populations, and organisms, as long term, short term, or seasonal.

  • design an investigation from a testable question related to change over time in ecosystems, communities, populations, or organisms. The investigation may be a complete experimental design or may focus on systematic observation, description, measurement, and/or data collection and analysis.

  • analyze and critique the experimental design of basic investigations related to change over time in ecosystems, communities, populations, and organisms.

LS.11 The student will investigate and understand the relationships between ecosystem dynamics and human activity. Key concepts include a) food production and harvest; b) change in habitat size, quality, or structure; c) change in species competition; d) population disturbances and factors that threaten or enhance species survival; and e) environmental issues.

LS.12 The student will investigate and understand that organisms reproduce and transmit genetic information to new generations. Key concepts include a) the structure and role of DNA; b) the function of genes and chromosomes; c) genotypes and phenotypes; d) characteristics that can and cannot be inherited; e) genetic engineering and its applications; and f) historical contributions and significance of discoveries related to genetics.

LS.13 The student will investigate and understand that populations of organisms change over time. Key concepts include a) the relationships of mutation, adaptation, natural selection, and extinction; b) evidence of evolution of different species in the fossil record; and c) how environmental influences, as well as genetic variation, can lead to diversity of organisms.