Answer:
Environmental exposure to certain chemicals, ultraviolet radiation, or other external factors can also cause DNA to change. These external agents of genetic change are called mutagens.
Answer:
D. They define geological periods because scientists use them as reference points for tracking the history of the earth.
Explanation:
Catastrophic events related to changes in geological timeline are very useful in defining geological periods.
These events have very significant appearance in the geological record and can be used to determine the history of the earth.
The catastrophic events usually culminates into extinction cycles or termination of some organisms from the earth surface.
Geologists use these events that are often wide spread to delineate geological periods.
Answer: Between 8 and 14
Explanation: Ammonia is an inorganic compound of formula NH₃. Also known as ammonium hydroxide, it behaves as a weak base.
pHydrion paper is a chemical test indicator, i.e., it indicates the pH of a substance.
If inserted in Ammonia, pHydrion will indicate a range of 8 to 14 because in pH scale, indication of base is over 8 and up to 14. The exact number depends on the hydrogen ion concentration of the substance.
The organism that Michelle is studying can best be classified into the domain EUKARYA.
The three domain classification system was introduce by a scientist named Carl Woese. The classification system categorizes all living organisms into three basic domains, which are: archaea, bacteria and eukarya. The archaea and the bacteria groups represent the prokaryotes while the eurkarya group represent the eukaryotes. Eukaryotic organisms are divided into plants and animals. The eukaryotic plants, even though they are multi cellular like animals have some features, which distinguish them from the animals, these include: ability to produce their own food and inability to move around their environment.
