It is believed that life could not have existed on land until which atmospheric layer formed? ozone layer ionosphere thermosphere exosphere

Fossils of marine organisms have been found on mountain tops in Canada. From this discovery, what conclusion is MOST reasonable about Canada's past? No conclusion can be drawn without knowing the age of the fossils. A river once ran from the mountain tops. Birds that eat marine animals lived on the mountain tops and carried the organisms to their nests. The land where the fossils were found was once covered by the ocean.

By studying the geologic time scale, scientists can best determine _________. developments and extinctions of plant and animal life changes in Moon phases differences in Earth's layers that fossils provide evidence of stable environmental conditions

Scientists are digging through three layers of rock looking for fossils. They discover reptile fossils in the top layer of the rock. Amphibian fossils are discovered in the middle layer of the rock. Finally, they find fish fossils in the deepest layer of the rock. The scientists use the order in which the fossils were discovered to theorize the order in which the organisms lived. Which organisms lived before the amphibians? fish reptiles both fish and reptiles amphibians lived before the fish and the reptiles

Techniques used to estimate geological time include _________________. observing rock sequences studying events such as earthquakes and tsunamis charting weather patterns predicting moon phases

Which answer choice describes the following principle? "Earth's present is the key to its past." succession radioactivity uniformitarianism absolute age

Some of Earth's processes include erosion, plate movement, and changes in atmospheric composition. Which of the following statements most accurately describes the history of Earth's processes? Earth's processes have greatly changed over time. Earth's processes have changed slowly over a long period of time. Earth's processes are similar to those that occurred in the past. Earth's processes have not changed at all.

Which of these conditions makes fossil formation more likely to happen? The organism is composed mainly of soft tissue. The organism is attacked by scavengers. The organism is invaded by bacteria and fungi. The organism contains some distinct hard parts.

What are fossils? old rocks and layers of sediment the preservation of rocks and minerals the remains of organisms which existed long ago petrified soft tissue at least 100 years old

The time it takes for half of the radioactive atoms in a sample of a radioactive element to decay is the element's relative age half-life potassium-argon date absolute age

Fossils, such as ______________, provide evidence of past life and environmental conditions. footprints and shells rocks hieroglyphics rare minerals

Digging in his backyard in Florida, Brian found a rock that contained a fossil. He was most likely digging in a kind of rock called ___________. granite limestone basalt marble

Which of the following best explains the importance of studying fossils? to provide information about current life forms and environmental conditions to provide information about how life and environmental conditions may have changed to provide information about how previous life forms would exist in current environmental conditions to provide information about how current life forms would exist in previous environmental conditions

How would you explain fossils of shallow sea creatures that are found in rock located in the desert? The environment was different long ago. The sea creatures were brought to the desert. Rock was transported from the sea to the desert. The sea creatures evolved to live in the desert.

The majority of the earth's surface is covered by _______________________. rock and sediment plates and mountains soil water

Look at the diagram above. If the rock layers have not been disturbed, which layer is the oldest? layer A Layer B layer C layer D

The diagram shows that continents of the Earth can be joined like pieces in a jigsaw puzzle. What conclusion can be drawn from the diagram shown? Continents moved in the past and are stationary now. All continents were part of one large landmass in the past. All continents are moving away from each other at a uniform speed. Continents are continuously moving closer to one another throughout history.

According to the fossil record, scientists have determined that life on Earth began about __________. 1 million years ago 3.5 billion years ago 65 million years ago 0.5 billion years ago

An insect has been trapped in sap which hardened into amber. What type of fossil has formed? an imprint fossil a cast fossil a mold fossil an intact fossil

Which type of fossil is formed when an organism gets trapped in a developing rock layer and then decays, leaving an imprint of its body? an intact fossil a cast fossil a mold fossil a petrified fossil

Which of the following would not be an example of a fossil? brachiopod in limestone trilobite in shale fern imprint in rock layer a broken fence post

Which type of fossil preservation is shown below? carbon film original remains trace fossil permineralized remains

Scientists can estimate the ages of rock if they contain certain __________. sediments fault boundaries minerals index fossils

Which of the following is NOT evidence of the Pangea theory? similar fossils found on separate continents similar coastlines fit like puzzles similar weather patterns similar geological features

Based on ________________, scientists have determined Earth to be about 3.5 million years old. the fossil record the distance from the Sun to Earth the appearance of modern day organisms the thickness of the mantle

Fossils provide evidence of __________________. how life has remained stable over time how the climate has remained stable over time how the environment has changed but life has remained stable over time how life and environmental conditions have changed over time

The formation of sedimentary rocks takes place when __________. magma cools down quickly magma cools down slowly rock material is deposited in layers rock material is compressed under the earth

Which type of rock is formed when magma from deep inside the earth comes to the surface and cools down to become a solid? igneous rock plutonic rock sedimentary rock metamorphous rock

Scientists have theorized that an asteroid hit the Earth about 65 million years ago. This asteroid wiped out the majority of living species, including the dinosaurs. The destructive force of the asteroid marked the end of the __________________. Paleozoic Era Precambrian Era Mesozoic Era Cenozoic Era

Which of these is formed when a rock is deformed due to high temperature and pressure? igneous rocks metamorphic rock igneous and metamorphic rocks sedimentary and metamorphic rocks