1. Why is it advantageous for scientises to test only one variable at a time during an experiment? 2. Distinguish between a variable and a control. 3. What is differentiation? 4. What are some advantages ande disadvantages of light microscopes and electron microscopes? 5. Explain why you cannot draw a conclusion about the effect of one variable in an investigation when the other key variables are not controlled.

answer; 60-100; beats per minute

prophase: we can observe the chromosomes to coil up and condense. they become visible. nuclear membrane and envelope disintigrate.s

metaphase: chromosomes align at the center, the metaphase plate. spindle fibers attach to centromeres of the sister chromatids. they meet at kinetochores.

anaphase: sister chromatids are pulled towards each opposing centromere, set on different poles.

telophase: chromosomes are now clustered up only on either sides of the cell. nuclear membranes reform, and a new cell wall forms along the cell plate. this will lead to cytokinesis, the process that divides the cell membrane and forms the cell wall.

yes, because even though a theory has a  lot of evidence to support it, it is not always true