BYU - Earth Science final exam study guide Questions And Answers With Verified Solutions

It is believed that an asteroid or comet impact caused the extinction of the dinosaurs 65 million years ago. What are the two major lines of evidence supporting this theory? - There is a layer of clay at the time of the dinosaurs with high concentration of iridium from asteroids in it, and scientists have found a large impact crater that hit Earth 65 million years ago. . Of the four Earth biomes shown below, which has the greatest number of species? - Rainforest A student collects the following data in a pond ecosystem. Which data represents an abiotic factor? - The pH, or acid level, in the pond is 6.3. Pure water has a pH of 7 Are the temperatures on Mars today too cold to support microbial life? - Yes. Life simply cannot be supported at -220°F. As Earth moves farther from the sun in its orbit, how does the sun's gravitational force on the earth change? - The force of gravity decreases. Bacteria - Biotic Communication in space requires a signal to be sent by waves with very large wavelengths. What is the best type of wave to use for a communication device in space? - radio waves Earth is swarming with life. Of the other planets in our solar system, which has an environment most suited for life? - mars Electromagnetic waves with very short wavelengths, such as x-rays and ultraviolet waves, are more energetic than long waves like radio and microwave radiation. - The wavelength of light from a star can be stretched or compressed depending on which direction the star is moving.Four students were asked to list one property of a star that can be measured by analyzing its spectrum. The answers are listed below. Which student answered incorrectly? - Student B: The spectrum can be used to calculate the mass of the star. How do astronomers know that heavy elements, like iron, are formed in stars? - They have found evidence of heavy elements in the nebula of dead stars How do scientists know that the universe is expanding? - Nearly everything shows a redshift in its spectrum. How do we know that the "guest star" reported by Chinese astronomers in 1054 AD was a supernova? - They reported that it had a reddish color and could be seen during the day.