Amoebae move by growing an extension of their bodies in the direction of movement and then flowing into it. This extension is called a pseudopod because when it's fully extended it resembles a limb, despite being only an extension of the amoeba's plasma membrane.
The answer is <span> b. a process of change through time.
Evolution is a process of change through time. It does not result in progress. Natural selection, one of the mechanisms of evolution, can result in progress and </span>cause some organisms to develop characteristics they need. But generally speaking, natural selection is not the only mechanism of evolution. Other evolutionary mechanisms, such as genetic drift, mutations, migration, can in some cases have a harmful outcome.
The separation of the sister chromatids during the cell division occurs in the anaphase in mitosis and anaphase II in meiosis.
During the anaphase in mitosis, and the anaphase II of the meiosis, the chromosomes aligned at the center of the nucleus separates and the sister chromatids of the chromosomes starts moving towards the opposite poles as the spindle fibers starts contracting.
In order for plants to assimilate nitrogen directly into their system, the nitrogen must be in the form of nitrates. Nitrogen in the air and ammonia from decayed matter in the soil is converted to ammonium by decomposers and nitrogen-fixing bacteria. The ammonium is further nitrified to nitrates by nitrifying bacteria. Finally, the nitrates can then absorbed by the plants.