ASIS International (ASIS) Professional Certified Investigator Practice Exam

The statement that DNA is found in cells that contain a nucleus is true because DNA serves as the genetic blueprint for most organisms, and in eukaryotic cells, which include plant and animal cells, it is housed within the nucleus. This compartmentalization of genetic material allows for complex regulation of gene expression and is a fundamental characteristic of eukaryotic life.

In contrast, prokaryotic cells, such as bacteria, do not have a nucleus; they contain their genetic material in a region called the nucleoid. However, the question specifies the presence of a nucleus, making the third statement correct in the context of eukaryotic cells, where DNA is indeed located within the nucleus.

The other statements do not accurately describe DNA. For instance, stating that DNA is always found in the cytoplasm is misleading, as in eukaryotic cells, it is specifically located in the nucleus. The notion that DNA is only found in animal cells is incorrect, as it is also present in all plant cells and many other types of organisms. Additionally, implying that DNA is unaffected by environmental factors overlooks the fact that factors such as temperature and chemical exposure can influence DNA structure and function, including potential damage and mutation.