Study the timeline. A timeline. 4.5 billion years ago, Earth is formed. 4.3 billion years ago, Earliest water. 4.1 billion years ago, Single celled life. 3.5 billion years ago, Earliest oxygen and photosynthesis. 2.5 billion years ago, Complex single celled life. 1.5 billion years ago, Multi cellular life. 500 million years ago, Land life. 300 million years ago, Dinosaurs. 200 million years ago, Mammals. 130 million years ago, Flowers. 5 million years ago, Humans.

Based on fossil evidence, about how long ago did the first single-celled life form appear on Earth?

130 million years ago
1.5 billion years ago
2.5 billion years ago
4.1 billion years ago
ITS 4.1 BILLION YEARS AGO!

The correct answer is - 4.1 billion years ago.

Explanation:

In the question, there is a timeline given based on the fossils evidence and on the base of this timeline, it is given that the earth formed around 4.5 Billion years ago. Soon after the earliest water, the first living unicellular single-celled organism found which is dated around 4.1 billion years ago.

It has appeared soon after the earth formed itself and after a billion years later the first photosynthetic organism occurred.

organisms that lack symmetry are called asymmetrical and belong to phylum porifera/sponges.

organisms with specialized stinging cells belong to phylum cnidaria. stinging cells are called cnidoblast cells.

cnidarians show two morphological forms : polyp (sessile) and medusa (mobile)

filter feeding is observed in porifera members.  

alternation of generation is observed in coelenterata or cnidaria. there is alternation of asexual polyp form and sexual medusoid form. it is also referred as metagenesis.

you did not attach the discourse, but i assume it to be the discourse on the origin and basis of inequality among men (the original titile in french is: "discours sur l'origine et les fondements de l'inégalité parmi les hommes"), also know as "second discourse". in this discourse, jean-jacques rousseau emphasizes that private property is the basis of all inequalities.

therefore, what enabled the old regime to maintain as long as it did was private property.