Arbitrary level refers to the fundamental vertical subdivision of an excavation square, implied only when easily identifiable natural strata are absent and when natural strata are more than ten centimeters thick.
Natural strata refer to a vertical subdivision of an excavation square, which is reliant on the natural breaks in the sediments in terms of grain size, color, hardness, texture, or other features.
It is important to know the difference between the arbitrary and natural levels as arbitrary levels could amalgamate artifacts from distinct natural levels, that is, of distinct geologic contexts.
The archaeologists can recover the smallest ecofacts and artifacts with the assistance of flotation, screening, and bulk matrix processing
Amino acids are acids on one hand, and a base on the other hand.
<h3>What is an acid?</h3>
An acid is a substance that produces hydrogen or hydroxonium ions as the only positively charged ion when it ionizes.
All amino acids have an amine group -
and a carboxylic group -
.
The carboxylic group ionizes such that:

The presence of the amine group enables amino acids to also act as a base.
More on amino acids can be found here: brainly.com/question/14583479
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<span>The correct answer for this question would be the S phase of the cell cycle. During the S phase, DNA is synthesised in the form of a complete copy, which is stored in the nucleus, as well as acting as a copy for a microtubule-organising structure referred to as the centrosome.</span>
2. The endosymbiotic theory suggests that a eukaryotic cell is the result of one prokaryotic cell eating another.
Answer:
b i hope it helps you !!!
Explanation: