Studies of gene mutation frequencies have shown that __________
A) mutations are rare, and genomes are generally stable
B) mutation frequencies differ among organisms and also between genes, suggesting certain genes are more susceptible to mutation
C) mutation frequencies are consistent between organisms, and each region of DNA is equally susceptible to random mutations
D) Both A and B are correct
E) Both A and C are correct
D
You might also like to view...
Biological diversity is composed of what three levels?
A. trophic diversity, ecosystem diversity, and species diversity. B. ecosystem diversity, species diversity, and process diversity. C. genetic diversity, function diversity, and process diversity. D. genetic diversity, species diversity, and ecosystem diversity.
Scarlet fever and rheumatic fever are both caused by
A. Clostridium tetani. B. Salmonella sp. C. Staphylococcus aureus. D. Streptococcus pyogenes.
For many years scientists believed that almost all animal lineages burst into being during the Cambrian era (just after the end of the Precambrian super eon)
However, there have been many recent findings of animal-like fossils and "trace fossils" (fossils of an animal-like organisms movement) from the late Precambrian. Which of the following best explains why it took so long to realize there was animal-like life in the Precambrian? A) Animals from the late Precambrian had soft bodies. B) There were many hard-shelled animals in the Cambrian. C) The global climate was such that there was poor fossilization in the Precambrian. D) There were very few animals during this period.
Which is incorrect about smallpox?
A. The poxvirus called variola is the etiological agent. B. The vaccine is effective even if given in the first few days after exposure. C. There is an effective vaccine. D. The last case was seen in 1977. E. Transmission is by ingesting contaminated water or food.