Final answer:
It is true that DNA deficiency can be fatal in mice. Mutations in DNA can result in defective proteins and diseases, which can be fatal. The extent of the impact of mutations ranges from beneficial to lethal, illustrating the importance of DNA integrity for organism viability.
Step-by-step explanation:
It is true that in mice, DNA deficiency can be fatal. DNA is critical in coding for proteins, and mutations in DNA can lead to the production of defective proteins. Such mutations can be significant enough to cause diseases or even lead to fatality. An example of this is the dominant lethal inheritance patterns seen in diseases like Huntington's disease, where gene mutations cause degeneration of nerve cells and death.
Mice, similar to humans, have bodily mechanisms that can repair some of the damage caused by radiation or environmental factors. However, if the DNA damage from high doses of radiation is overwhelming, it can result in irreversible damage. Mutations like those in the glucose 6-phosphate dehydrogenase (G6PD) gene can even have mixed effects such as causing anemia but also proving beneficial by decreasing susceptibility to malaria. This varying impact confirms that the relationship between DNA integrity and an organism's viability is complex and multifaceted.