primitive life forms

Summary - Earth is said to have been formed about4.8 billion years ago. Earliest earth was a hot revolving ball of gas. The formation of first cells in planet earth is explained by the theory of chemical evolution proposed by Oparin and Haldane, independently. According to this theory, th..

Origin of Life - Philosophers and scientists from time immemorial have attempted to explain how and where life originated on this planet earth. Today, earth is the only planet where life exists. However, when the earth was formed about 4.8 billion years ago, ..

Philosophers and scientists from time immemorial have attempted to explain how and where life originated on this planet earth. Today, earth is the only planet where life exists. However, when the earth was formed about 4.8 billion years ago, there was absolutely no sig..

The Life of a Star - The life cycle of a star begins with the accretion of hydrogen and helium gas at -173 o C into smaller dense clouds, which contract under their own gravity. This dense cloud of gas contracting under its own gravity is called a Protostar . A cloud of gas from..

Steps in the Origin of Life - The earth when it was formed about 4.8 billion years ago, was a hot revolving ball of gas consisting of atoms of various elements. Heavy elements such as iron and nickel were found in the center while comparatively lighter ones like those of alumini..

Angiosperms exhibit a great diversity in form, size, structure and life span of the plant body. Based on the duration of life span, angiosperms are classified into annuals, biennials and perennia..

Forests and Wild Life - The biotic component of our environment on land, i.e. plants and animals (leaving aside the oceans and other water bodies) are overwhelmingly found in forests. Forests form a buffer for the earth to protect life forms; in fact that's w..

Summary - Our body is made up of tissues, which are all composed of chemicals. We need an adequate supply of chemicals in the form of food, vitamins, hormones, and enzymes, which are in turn chemicals. For taking care of our health we need medicines. We find that chemicals and chemistry p..

Science is the hallmark of progress in the realm of naturally occurring matter and energy. It is the way one has to get at the truth or at least, as close to the truth as possible. WHAT is Science? * Science is a human endeavour * Science is an interaction of human mind with the facts of ..

Introduction - The cells that make up our body are so small that you could fit over 200 of them on the full stop at the end of this sentence Before we plunge into the chapter, here are some interesting facts about cells. Read on... The word cell is derived from the Latin word cellula which means a ..