<u>Answer:</u>
All of the above mentioned options can be used by scientists to date the sediment layer they are found in.
<u>Explanation:</u>
- Rock fossils, animal fossils, etc.found in the sediment layer can be used to determine the age of the sediment based on the period of the existence of that animal or the period of formation of the rock.
- Tree rings clearly exhibit the age of the tree. Hence, a sediment layer with the evidence of tree rings can tell the age of the sediment layer.
- An amalgamation of the data obtained from the animal growth rings and the period of existence of that specific animal species can be used to calculate the age of the sediment.
- The intensity of radioactivity left in the isotopes clarifies how old the isotope is.
- The age of mineral elements can be determined exactly with the help of processes like Potassium-Argon dating, Uranium-Lead dating, etc.
- Thus it would be easy to determine the age of the sediment layer containing mineral elements.
Answer:
2 g/ml
Explanation:
D= M/V
80g divided by 40 ml= 2 g/ml
The correct answer is - cyanobacteria.
The atmospheric oxygen came from the cyanobacteria. These were one of the earliest living organisms on Earth. The cyanobacteria was using photosynthesis in order to create its own food. The photosynthesis process requires sunlight, carbon dioxide, water, and oxygen. The oxygen is mostly released as a waste product from the process of photosynthesis, thus the cyanobacteria were literally releasing oxygen that was ending up into the atmosphere. As more and more cyanobacteria there were across the planet, more and more oxygen they were releasing into the atmosphere, slowly changing the composition of the atmosphere, and setting the basis of it as we know it now.
An orogenesis is a general term for the processes that produce mountains.
The correct option is C.
Plate tectonic theory explains the structure of the earth's crust and the many phenomena that are associated with it. This theory enables the scientists to know that there are movements in the interior of the earth which are responsible for volcanic eruptions and earthquakes.
