Although human activites are reducing the extent of many biomes, they are causing the spread of deserts, a process called desertification. Rain forests are being felled for lumber or burned down for ranching or agriculture. Africa's rapidly expanding human population threatens the wildlife of the savanna. The tallgrass prairie has been converted to agricutural land. Clearing for lumber, agriculture, and housing has dramatically reduced America's deciduous forests.

Composting is a process in which purely organic waste is converted into a rich soil conditioner commonly known as 'compost'. The process usually begins with household food and plant scraps, which are broken down over time and added to soil to fertilize the soil and help it retain moisture.

"Habitat connectivity" is the only term that describes something positive that increases the quality of biodiversity. It is defined as the degree to which landscape facilitates movement and ecological flows important for the survival of other species. Every other term describes things that decrease habitat and negatively impact biodiversity.

The correct response is "eutrophication." It is the only term that is specific to aquatic systems and the input of excess nutrients by way of pollution. The terms "bioaccumulation" and "biomagnification" describe how substances such as toxins accumulate within organisms and trophic levels—not an aquatic ecosystem. Last, "fragmentation" has nothing to do with the question because it refers to when habitats are parceled apart due to human activities.

The correct response is “heterogeneous landscapes.” This is the only answer choice that describes landscapes with different types of habitats. Different types of habitat are necessary to maintain biodiversity. "Uniform" and "Homogeneous" describe landscapes that are very similar. "Artificial Landscape" does not arise from a natural process. 

Environmental science integrates information from several fields. These fields include the natural and physical sciences such as biology, chemistry, and geology; but social science and humanity fields are important to the study of the environment. These fields include political science, economics, and ethics. Environmental science studies organisms, including humans, and their environment as well as their affect on the environment.

Much of the solar energy that enters earth is absorbed by atmospheric molecules or reflected off of surfaces, and a large portion of the energy is unsuitable for photosynthesis. Photosynthesis is powered by light energy that has wavelengths ranging from 400 to 700 nanometers (nm), while sunlight has a wavelength range from 250 to 2500 nm. As a result, only about 1% of available solar energy is used for photosynthetic activity.

Chlorophyll a and b absorb visible light wavelengths in the purple, blue, and red ranges of the visible spectrum of light and reflect visible light in the green range. The green color of leaves is a result of the green visible light being reflected back and isolated from the other visible colors in the spectrum that were absorbed.

During photosynthesis, plants and algae use solar energy to convert carbon dioxide and water to glucose and oxygen. Phosphorus is not involved in the photosynthesis chemical reaction as a reactant or product.

Cellular respiration is the opposite reaction of photosynthesis:

Photosynthesis converts carbon dioxide, water, and solar energy to sugar and oxygen. Respiration uses oxygen and sugars to provide a cell with energy. Water and carbon dioxide are produced as byproducts. Note that the form of energy used in photosynthesis is sunlight, while the form of energy produced during respiration is chemical energy.