What is a vacuole? Parts of a cell – Biology
Vacuoles in an amoeba (a one-celled eukaryote) Vacuoles are little pockets in the cytoplasm of a cell where a cell stores food. You can see them with a good light [...]
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05, 2017
How do eukaryote flagella move cells?
Human sperm cells with flagella (under a microscope): Eukaryote flagella Not the old kind of flagella About two billion years ago, the first eukaryote cells evolved from the earlier prokaryote [...]
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05, 2017
What is Tay-Sachs disease? Lysosomes and cell biology
Krystie has Tay-Sachs disease Tay-Sachs is a disease where your lysosomes aren't working right. It's a disease you get in your DNA from your parents. Both your mother and your [...]
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05, 2017
What is RNA? Cell biology and evolution
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 [...]
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05, 2017
Cell reproduction – Biology
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 [...]
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05, 2017
What is a nucleus – Parts of a cell – Biology
An onion skin cell (seen through a microscope) You can see the nucleus inside each cell The earliest cells, and all prokaryote cells, don't have a nucleus. Inside these simple [...]
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05, 2017
What are mitochondria? Parts of a cell
A mitochondrion (seen through a microscope) When did mitochondria evolve? About two billion years ago, in the Proterozoic, there were only prokaryotic cells on Earth. Mitochondria probably started out as [...]
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05, 2017
What are lysosomes? Parts of a cell – Biology
Lysosomes (under an electron microscope) When did lysosomes evolve? Prokaryote cells don't have lysosomes, so the first ones probably evolved about the same time as the other pieces of eukaryote [...]
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05, 2017
What are lipids? Cell biology
Highly magnified view of a cell wall made of lipids When did the first lipids form? Around four billion years ago, some of the amino acid molecules that were on [...]
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05, 2017
How did cells evolve? Cell biology and evolution
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 [...]
