Answer:
The testes are two oval-shaped male reproductive glands that produce sperm and the hormone testosterone.
Answer:
Greenhouse gases from human activities are the most significant driver of observed climate change since the mid-20th century.1 The indicators in this chapter characterize emissions of the major greenhouse gases resulting from human activities, the concentrations of these gases in the atmosphere, and how emissions and concentrations have changed over time. When comparing emissions of different gases, these indicators use a concept called “global warming potential” to convert amounts of other gases into carbon dioxide equivalents.
Explanation:
Why does it matter?
As greenhouse gas emissions from human activities increase, they build up in the atmosphere and warm the climate, leading to many other changes around the world—in the atmosphere, on land, and in the oceans. The indicators in other chapters of this report illustrate many of these changes, which have both positive and negative effects on people, society, and the environment—including plants and animals. Because many of the major greenhouse gases stay in the atmosphere for tens to hundreds of years after being released, their warming effects on the climate persist over a long time and can therefore affect both present and future generations.
Answer:
Mississippian fossils are abundant in portions of the Midwest and South and include vast beds of limestone and marble.
Explanation:
For example, the domed ceiling of the Jefferson Memorial in Washington, D.C., is made of Indiana limestone that was deposited during the Mississippian Period.By the end of the Carboniferous, reptiles had migrated well toward the interior of Pangea. These early pioneers went on to spawn the archosaurs, pelycosaurs, and therapsids of the ensuing Permian period. (It was the archosaurs that went on to spawn the first dinosaurs nearly a hundred million years later.)
