1. What are the relationships among Earth's mantle, crust, astheno¬sphere, and lithosphere?
The Earth’s mantle, crust, asthenosphere and lithosphere are all related. The Earth’s crust is the layer on the Earth’s surface. It is an outer layer of rock. Geologists believe that the Earth’s crust is thinner in the areas underneath of the oceans than it is under land masses (Carlson, Plummer & Hammersley, 2009). The Earth’s mantle is below the crust. It is the thick layer of rock that separates the crust from the Earth’s core. Geologists believe that the core may be metallic, and is the most likely source of Earth’s magnetic fields (Carlson, Plummer & Hammersley, 2009) . The Earth’s crust, the Earth’s mantle, and the lithosphere are all related because the Earth’s crust and mantle together form the lithosphere. The lithosphere is the Earth’s crust and the upper part of the Earth’s mantle. In the plate-tectonic theory, the lithosphere is the plates (Carlson, Plummer & Hammersley, 2009). The zone in the lithosphere where seismic waves slowdown is called the asthenosphere. This zone is approximately one hundred and twenty four miles deep. The rocks in the asthenosphere are closer to their melting point than other zones, and may move more freely. It is important to note that these rocks may not be hotter than in other areas, but that melting point is related to pressure. It is believed that magna is generated in the asthenosphere (Carlson, Plummer & Hammersley, 2009).

2. By what processes did the planets form from the clouds of gas and dust? What are some of the main differences between the Earth-like planets and the giant outer planets such as Jupiter and Saturn?
Immanuel Kant and Pierre Simon Laplace hypothesized that the solar system was formed from the solar nebula, a flat disk of gas and dust. The outer part of this disk became the planets, and the inner part became the sun. The modern form of this hypothesis is the Nebular Hypothesis.
Some of the main differences between Earth-like planets and the giant outer planets such as Jupiter and Saturn are temperature, atmosphere, and geologically active surfaces (Carlson, Plummer & Hammersley, 2009).
3. Describe the Earth's magnetic field and the magnetic poles.
A magnetic field is an area of magnetic force. It is invisible, and it surrounds the Earth. This field is what makes things like compass needles work. Earth’s field is called dipolar because it has to poles, the North Pole, and the South Pole. They are located in the respective geographical areas corresponding with their names; however, the magnetic poles seem to be slowly moving around the geographic poles. This is because the Earth’s field isn’t 100% dipolar. It is believed that the source of the Earth’s magnetism is the liquid metal in the Earth’s core (Carlson, Plummer & Hammersley, 2009).
4. Differentiate between seamounts, guyots, and aseismic ridges.
Seamounts are undersea mountains that are tapering in shape. They are 3,280 feet or more above the sea floor. Some rise to sea level and form islands. They are in various places along the mid-oceanic ridge and sea floor, including on the abyssal plains. There are approximately 10,000 seamounts in the western Pacific, which is a high concentration. Because most rocks from seamounts are basalt, it is believed that seamounts may be extinct volcanoes. Very few seamounts are currently active volcanoes, but the majority of the ones that are active are located on the crests of the mid-oceanic ridges (Carlson, Plummer & Hammersley, 2009).
Guyots are seamounts, however they differ slightly because they are flat topped. They are mostly located in the western Pacific Ocean. It is commonly believed by geologists that the guymots are flat topped because they were cut by the ocean’s waves (Carlson, Plummer & Hammersley, 2009).
Seamounts and guyots are aligned in chains on the sea floor. Similar volcanic chains along with other ridges are called aseismic ridges. These ridges are not connected with earthquakes (Carlson, Plummer & Hammersley, 2009).
5. How does the age of sea-floor rocks compare with the age of continental rocks?
Earth is approximately 4.5 billion years old. Continents have rocks formed during the Paleosoic and Precambrian eras. Some of these Precambrian rocks are more than 3 billion years old, and a few that are about 4 billion years old have been found. Most sea floor rocks are 200 million years old or younger (Carlson, Plummer & Hammersley, 2009).

References:

Carlson, D. H., Plummer, C. C. and Hammersley, L. (2009). Physical Geology: Earth Revealed, 9th Ed., McGraw-Hill, New York, NY.