A biologist was working with a cell culture. He viewed a cell just before it entered mitosis and he counted 18 chromosomes. Later, the nucleus of one of the daughter cells was found to contain 19 molecules of DNA and the nucleus of the other daughter cell contained 17 molecules of DNA. Provide a possible explanation for his observation.

Which statements best describe the differences or similarities between a comparative investigation and an experimental investigation? check all that apply. experimental investigations are best for showing cause-and-effect relationships, while comparative investigations do not necessarily show this type of relationship. comparative investigations are often impractical and unrealistic, while experimental investigations are the most practical and realistic kinds of investigations. comparative investigations allow for the use of a wide range of variables but do not have a control group, while experimental investigations involve variables that can be controlled. both experimental investigations and comparative investigations are designed to answer scientific questions. both experimental investigations and comparative investigations focus on making observations rather than collecting new data.