Archaean

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23 06, 2017

What happened in the Archaean Eon?

By |2019-01-31T05:48:29-07:00June 23rd, 2017|Geology|4 Comments

Archaean Eon: A volcano erupts out of the water The beginning of the Archaean Eon After the end of the Hadean Eon is the beginning of the Archaean Eon. That's about 3.8 billion years ago. Earth was still about three times as hot as it is today. But it was no longer hot enough to [...]

2 06, 2017

What is nitrogen? Atoms, Elements, Chemistry

By |2018-04-24T14:46:22-07:00June 2nd, 2017|Chemistry|0 Comments

Diagram of a nitrogen atom Inside a red giant star, the star smashes lighter atoms together. Smashing atoms gets the star energy to burn, and also leaves extra heavier atoms. Nitrogen is one of these heavier atoms, left over when a star smashes together carbon atoms. Nitrogen is not very heavy, though, and a [...]

29 05, 2017

Evolution of Cells – Biology

By |2018-04-13T17:03:50-07:00May 29th, 2017|Biology|0 Comments

A mutated snake with two heads With all these new molecules like lipids, amino acids, RNA, and protein floating around in the oceans by around four billion years ago, there were a lot of new possibilities for what could bump into what. Sometimes a group of lipid molecules happened to stick together and [...]

29 05, 2017

How do cells move around? The flagellum

By |2019-06-10T05:47:04-07:00May 29th, 2017|Biology|0 Comments

Bacterium with a flagellum (under a microscope) Cells drift in the current... The simplest cells, developing about four billion years ago, had no way to control their own movement. They lived in the oceans, and they floated wherever the water took them. Sometimes they found food there, and sometimes they didn't. Most cells [...]

29 05, 2017

What is RNA? Cell biology and evolution

By |2018-04-16T00:39:56-07:00May 29th, 2017|Biology|0 Comments

RNA molecule: A single strand of RNA, seen under an electron microscope The RNA molecule was probably one of the earliest steps towards life on Earth. RNA is short for "ribonucleic acid". That's a very long, complicated molecule made out of amino acids linked together. The amino acids are made out of atoms of [...]

29 05, 2017

Cell reproduction – Biology

By |2019-03-08T06:54:01-07:00May 29th, 2017|Biology|0 Comments

A cell dividing into two cells The first reproduction One of the main ways we define whether something is alive is whether it can reproduce - if it can make a new version of itself. The first things we know about that could reproduce were molecules of RNA, more than four billion years ago. What is [...]

29 05, 2017

What is a prokaryote – Cell biology

By |2018-09-11T05:51:18-07:00May 29th, 2017|Biology|0 Comments

A prokaryote (seen through a microscope) What does "prokaryote" mean? The simplest living cells are called prokaryotes, which is Greek for "before the nucleus" - these are cells that were so simple that they didn't have a nucleus. When did the first prokaryotes evolve? The first prokaryotes probably evolved from even simpler cells [...]

29 05, 2017

What is photosynthesis? Plant Biology

By |2018-04-16T00:37:36-07:00May 29th, 2017|Biology|1 Comment

Chloroplasts (seen through a microscope) Photosynthesis is the way some cells on Earth pull in light from the sun and use it to make energy to repair and reproduce themselves. The first cells could not photosynthesize (foe-toe-SIN-the-size). They got food by breaking apart hydrocarbon molecules. But a little more than three billion years ago, [...]

28 05, 2017

How did cells evolve? Cell biology and evolution

By |2018-04-16T00:35:42-07:00May 28th, 2017|Biology|0 Comments

One cell of a plant (magnified 22,500 times) Thanks to Ohio State University A cell is the smallest living thing (unless you count viruses), and all bigger living things are made of cells. Both plants and animals are made of cells. We don't know yet whether there are cells on any other planet [...]

28 05, 2017

What is DNA? Genetics and Evolution – Biology

By |2019-05-13T19:58:16-07:00May 28th, 2017|Biology|2 Comments

A strand of DNA (seen through an electron microscope) Let's start with RNA If the RNA theory of the origin of life is right, then after a short time, about four billion years ago, the oceans on Earth had a lot of these strands of RNA molecules floating around in them. RNA molecules made proteins, [...]