Answer:
In Late 1600s Anton von Leeuwenhoek develops a more powerful microscope that allows him to see living cells like bacteria.
In Early 1800s Matthias Schleiden and Theodor Schwann conclude that all living organisms are made of cells, and that cells can be produced from other cells.
Explanation:
Answer:
B) Absence of native grasses
Explanation:
The grasses, which acted as a windbreak and whose roots anchored the soil in place, were overgrazed and/or removed to allow for farming. Once a few years of severe drought affected the area, any wind storm was able to blow the topsoil away, rendering the farm land of the Great Plains virtually unusable in many areas. Ground cover is an essential part of sustainable agriculture.
Lakes that have been acidified cannot support the same variety of life as healthy lakes. As a lake becomes more acidic, crayfish and clam populations are the first to disappear, then various types of fish. Many types of plankton-minute organisms that form the basis of the lake's food chain-are also affected. As fish stocks dwindle, so do populations of loons and other water birds that feed on them. The lakes, however, do not become totally dead. Some life forms actually benefit from the increased acidity. Lake-bottom plants and mosses, for instance, thrive in acid lakes. So do blackfly larvae.
