Answer:
In a pedigree chart, the line which is horizontal shows the parents which mated and produced the children which are represented in the vertical lines below them.
A pedigree chart can be described as a diagram which illustrated the sequence of ancestors of an individual. Often, a pedigree chart is used to look for genetic traits or genetic disorders which might run in the family history. Pedigree charts are important for understanding the probabilities of the offsprings in which a genetic disorder might occur due to family history.
Answer:
The fossils that provide information on the formation of an oxygen-rich atmosphere are the stromatilites from the Precambrian era. These are layered and columnar fossils consisting mainly of cyanobacteria which were the original life form back then. These bacteria took in carbon dioxide and produced oxygen by photosynthesis as early as 2.5 billion years ago (the earth is about 4.5 billion yrs old).
Explanation:
Answer:
The answer is the dropping pH of the ocean
Explanation:
The ocean absorbs tons of carbon dioxide (Co2) from the atmosphere which changes the chemistry of the water. The ocean is naturally Alkaline but, as the oceans absorb Co2 it turns into carbolic acid. This doesn't make the ocean's immediately acidic but it is causing them to be gradually less alkaline. Since the direction of change is near the acid end of the scale, the process is known as ocean acidification. The coral reefs need the alkaline environment and can feel when the environment changes and when the ocean becomes to acidic for them it kills off the coral.