matter in our surroundings

The physical meaning of entropy is that entropy is a measure of degree of disorder (or randomness) of a system. The relation between entropy and disorder provides a suitable explanation for entropy change in various processes. The greater the disorder in a system, the higher is the entropy. Obviou..

Any system where there is a constant exchange of matter and energy from the surrounding environment is called as open system. All living organisms represent open systems. Any state of a system where the rate of input of energy and matter is equal to the rate of..

: Crystalline Amorphous In a crystalline substance, a definite well-defined external geometric shape such as cube, octahedron or tetrahedron characterizes the soli..

Second Law of Thermodynamics - The second law of thermodynamics introduces the concept of entropy and its relation with spontaneous processes. In an isolated system such as mixing of gases, there is no exchange of energy or matter between the system and the surroundings. But due..

It is a collection of nervous tissue running along the back bone. It is, in fact, protected by the vertebral column. It is a continuation of the brain. Spinal Cord It consists of a central canal that has cerebrospinal fluid that is continuous with the fluid in the brain. The canal is surr..

Breaking down food into simpler forms is called digestion. Digestion is both mechanical and chemical . In mechanical digestion, food is physically broken down into smaller particles by processes such as chewing. Chemical digestion makes use of certain chemicals called enzymes . They are protei..

Organism and Environment - Each and every living organism has its specific surrounding medium of environment with which it continuously interacts and remains fully adapted. The environment is the sum total of physical and biotic conditions influencing the responses of the organisms. The l..

Internal Energy - Internal energy is one of the most important concepts in thermodynamics. Energy changes in a body sliding with friction. Warming a body increases its internal energy and cooling the body decreases its internal energy. However, what is internal energy? We can look at it in various ..

A typical nephridium consists of a ciliated funnel or nephridiostome which opens into the coelomic cavity. This is followed by a short and narrow tube called the neck which is bent on itself and opens into the main body of the nephridium. The main body of the nephridium consists of a short straight..

Digestion - breaking down food into simpler forms. Digestion is both and chemical . The digestion may take place outside cells ( extracellular ) or within the cells ( intracellular ). Absorption - Taking in of food in the soluble forms into the tissues. The absorption may be passive (without ..