Posted in Science and Technology

Regeneration of Organs in Animals

Some parts of our bodies can repair themselves quite well after injury, but others don’t repair at all. We certainly can’t regrow a whole leg or arm, but some animals CAN regrow – or regenerate – whole body parts. So what can we learn from these regenerative animals?

Many animals can regenerate-that is, regrow or grow new parts of their bodies to replace those that have been damaged. Here are a few of these amazing creatures.

Axolotl can regenerate a variety of structures, including their limbs

Planarians are flatworms. If cut into pieces, each piece can grow into a new worm.

Lizards who lose all or part of their tails can grow new ones. This is a good escape technique. A lost tail will continue to wiggle, which might distract the predator and give the lizard a chance to escape. Most lizards will have regrown their tail within nine months.

Sea cucumbers have bodies that can grow to be three feet long. If cut into pieces, each one can become a new sea cucumber.

Sharks continually replace lost teeth. A shark may grow 24,000 teeth in a lifetime.

Spiders can regrow missing legs or parts of legs.

Sponges can be divided. In that case, the cells of the sponge will regrow and combine exactly as before.

Starfish that lose arms can grow new ones; sometimes an entire animal can grow from a single lost arm.

Humans can regenerate Skin and Liver

Mouse can regenerate Liver

Zebrafish can regenerate heart tissue without relying on stem cells

Like a starfish, an octopus can regrow lost arms. Unlike a starfish, a severed octopus arm does not regrow another octopus.

Posted in World History


updated on March 12th, 2019


During the Renaissance, extraordinary accomplishments were made in the field of science. We have already read that the Renaissance thinkers emphasized more on reason than on blind faith and stressed that knowledge could be gained by observation and experimentation. They rejected blind faith in tradition and established beliefs. This resulted in a scientific inquiry that had almost disappeared. Renaissance also brought about a scientific revolution. Artists like Leonardo da Vinci made observational drawings of anatomy and nature which were a unique blend of science and art. The period also saw remarkable achievements in medicine and human anatomy. Michael Servetus, a Spanish doctor, discovered the circulation of blood. William Harvey, an Englishman explained the function of the heart in purifying blood and its circulation through veins. The beginnings that were made by the Renaissance scientists paved the way for observation and experimentation in other fields of knowledge.

One of the most remarkable achievements of the Renaissance in science was in the field of astronomy. Have you heard of Copernicus, Kepler and Galileo? They were great astronomers who formulated and tried to prove that the Earth revolves around the Sun. Before the Renaissance, it was believed that the Sun revolved around the Earth and whoever questioned this was denounced as a heretic. Copernicus in his book On the Revolution of the Heavenly Sphere argued that the earth and the planets move around the sun in concentric circles. Even though the theory was imperfect, it aroused thinking and reasoning. Kepler further developed this theory and said that the other planets move in elliptical paths around the sun. He also argued that magnetic attractions between the Sun and the planets kept the heavenly bodies in an orbital motion. Further on this assumption, Isaac Newton developed his Law of Universal Gravitation. With his self manufactured telescope, Galileo discovered the moons of Jupiter, the rings of Saturn and spots in the Sun. He also confirmed the findings of Copernicus. Renaissance also developed a curiosity in the minds of Europeans about other lands and other peoples. Let us find out how this happened.

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