A cleft also called parted leaf is one in which the margins between the irregular teeth go more than halfway to the midrib. It is usually misty and cloudy. Huge club mosses went extinct during the Permian mass extinction; smaller ones lived during the time of the dinosaurs. These plants live near moisture in order for their spores to germinate.
For example, rock layers show the sequence of geological events, and the presence and amount of radioactive elements in rocks make it possible to determine their ages.
Analyses of rock formations and the fossil record are used to establish relative ages. In an undisturbed column of rock, the youngest rocks are at the top, and the oldest are at the bottom. Rock layers have sometimes been rearranged by tectonic forces; rearrangements can be seen or inferred, such as from inverted sequences of fossil types.
The rock record reveals that events on Earth can be catastrophic, occurring over hours to years, or gradual, occurring over thousands to millions of years.
Records of fossils and other rocks also show past periods of massive extinctions and extensive volcanic activity. Although active geological processes, such as plate tectonics link to ESS2.
B and erosion, have destroyed or altered most of the very early rock record on Earth, some other objects in the solar system, such as asteroids and meteorites, have changed little over billions of years. Page Share Cite Suggested Citation: A Framework for K Science Education: Practices, Crosscutting Concepts, and Core Ideas.
The National Academies Press. Major historical events include the formation of mountain chains and ocean basins, volcanic activity, the evolution and extinction of living organisms, periods of massive glaciation, and development of watersheds and rivers.
Because many individual plant and animal species existed during known time periods e. C By the end of grade 2. Some events on Earth occur in cycles, like day and night, and others have a beginning and an end, like a volcanic eruption.
Some events, like an earthquake, happen very quickly; others, such as the formation of the Grand Canyon, occur very slowly, over a time period much longer than one can observe.
By the end of grade 5. Earth has changed over time. Understanding how landforms develop, are weathered broken down into smaller piecesand erode get transported elsewhere can help infer the history of the current landscape. Local, regional, and global patterns of rock formations reveal changes over time due to Earth forces, such as earthquakes.
The presence and location of certain fossil types indicate the order in which rock layers were formed. By the end of grade 8. Major historical events include the formation of mountain chains and ocean basins, the evolution and extinction of particular living organisms, volcanic eruptions, periods of massive glaciation, and development of watersheds and rivers through glaciation and water erosion.
Analyses of rock strata and the fossil record provide only relative dates, not an absolute scale. By the end of grade Radioactive decay lifetimes and isotopic content in rocks provide a way of dating rock formations and thereby fixing the scale of geological time.
Continental rocks, which can be older than 4 billion years, are generally much older than rocks on the ocean floor, which are less than million years old. Tectonic processes continually generate new ocean seafloor at ridges and destroy old seafloor at trenches.
B and erosion, have destroyed or altered most of the very early rock record on Earth, other objects in the solar system, such as lunar rocks, asteroids, and meteorites, have changed little over billions of years.
Weather and climate are shaped by complex interactions involving sunlight, the ocean, the atmosphere, clouds, ice, land, and life forms. Earth is a complex system of interacting subsystems: The geosphere includes a hot and mostly metallic inner core; a mantle of hot, soft, solid rock; and a crust of rock, soil, and sediments.
The atmosphere is the envelope of gas surrounding the planet. The hydrosphere is the ice, water vapor, and liquid water in the atmosphere, ocean, lakes, streams, soils, and groundwater. The presence of living organisms of any type defines the biosphere; life can be found in many parts of the geosphere, hydrosphere, and atmosphere.
Solid rocks, for example, can be formed by the cooling of molten rock, the accumulation and consolidation of sediments, or the alteration of older rocks by heat, pressure, and fluids.PLANT ENERGY TRANSFORMATIONS 2. Photosynthesis: When life originated on this planet some billion years ago, the first life forms were single celled heterotrophs.
Photosynthesis takes place within cells on plants' leaves. Throughout the day, photons hit the plants leaves. Within these halls of antennae, incident photons generate electrons via the photoelectric effect.
LEARNING OBJECTIVES By the end of this lecture you will be able to: Understand that ENERGY can be transformed from one form to another. Know that energy exist in two forms; free energy - available for doing work or as heat - a form unavailable for doing work.
The Sun is the star at the center of the Solar urbanagricultureinitiative.com is a nearly perfect sphere of hot plasma, with internal convective motion that generates a magnetic field via a dynamo process.
It is by far the most important source of energy for life on urbanagricultureinitiative.com diameter is about million kilometers, i.e. times that of Earth, and its mass is about , times that of Earth, accounting for.
Creation of sugars. Chlorophyll plays a role in giving the plant the energy needed to convert CO2 and water into sugar during daylight hours.
The left over oxygen is a waste product for the plant and is released through the leaves. Photosynthesis: Photosynthesis, process by which green plants and certain other organisms transform light energy into chemical energy.