Devonian Period – fish, lungfish
Coelocanth: a fish from the Devonian period When was the Devonian period? Four hundred and sixteen million years ago, when the Silurian period ended and the Devonian period began, most [...]
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06, 2017
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05, 2017
Seeds – Plant reproduction – Biology
Evolution of seeds: Dandelion seeds What is a seed? A seed is the egg cell of a plant, with a hard wrapper around it so it can survive on its [...]
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05, 2017
Plant reproduction – Biology – Science
Cell division The very earliest photosynthesizing plants on Earth, about 3 billion years ago, had only one cell, and they reproduced the way most one-celled creatures do, by mitosis: splitting [...]
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05, 2017
Evolution of bones – Skeletons and Biology
A fish skeleton Before there were bones One-celled animals don't have any support system that holds them in a certain shape. Plants do have a support system, but it's the [...]
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05, 2017
Why do we have fingers? Skeletons, Evolution, and Biology
Human hand bones The first fingers and toes evolved from earlier fish fins about 400 million years ago. During the Devonian period, the oceans were very shallow, and some fish [...]
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05, 2017
Digestive System – Biology and Evolution
Digestive system: A hydra eating: the mouth is where all the tentacles come together,near the center of the picture.The hydra is eating the round bug in its stomach. Before digestive [...]
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05, 2017
Lungfish – Evolution of Fish
Evolution of fish: a lungfish Why did fish leave the water? About 400 million years ago, during the Devonian period, the Earth was going through an especially warm period. Some [...]
