Eutrophication is the input of excessive nutrients into fresh surface waters. Nutrients can cause algal blooms. Some of these algae can be toxic, and algal death can also result in anoxic conditions, leading to fish deaths. Some indicators of eutrophic conditions can be high measures of important nutrients such as phosphates and nitrates. Another indication of eutrophication can be high concentrations of algal cells. Finally, low dissolved oxygen can indicate eutrophic conditions.
D. they are formed when atoms of different elements combine
Prophase of mitosis do the chromosomes become distinctly visible in the microscope.
During metaphase, the nucleus dissolves and the cell's chromosomes condense and move together, aligning in the center of the dividing cell. At this stage, the chromosomes are distinguishable when viewed through a microscope. The first stage of mitosis and of meiosis I and II.
During prophase the chromosomes become visible as distinct structures, the nuclear envelope breaks down, and a spindle forms (Meiotic prophase I is more complex, and includes synapsis of homologous chromosomes and crossing over). During Prophase chromosomes become Clearly visible, nuclear envelope disappears, kinetochores and spindle fibers form.
To learn more about prophase , here
brainly.com/question/13883655
#SPJ4
