i have a question in biology??

Question

many pepole say that use of energy is a characteristic of life ,discuss why this should or should not be consider a characterstic of life .list examples

Answer 1

There are many factors that make up a life form and energy use is only one
The best example of what is close to life and is not life is Fire.

According to Wikipedia: http://en.wikipedia.org/wiki/Definition_of_life
Life forms have these characteristics in common.
·They reproduce themselves.
·They consume energy
·They generate waste
·Life forms grow.
·They have a cellular structure
·They respond to stimuli
·Through natural selection they adapt.

Fire can do a lot of this, but it doesn’t have a cellular structure and it doesn’t adapt. However it reproduces itself, consumes energy, generates waste, grows, and with seed like sparks it can reproduce itself. It can even respond to stimuli like the wind, but that is more a case of physics rather than responding. One fire is the same as any other fire (the fuel may vary though, which will create other forms of waste). Fire cannot adapt, if always follows the same rules that any other fire follows and it will never change that.

The internal combustion engine is not alive, but it takes the fuel and converts the hydrocarbons in it into energy, which it then transmits to the car through the fan belts and the crankshaft, and then it generates waste. The car parts could be called specialized cells and the car responds to stimuli from the controls that the driver uses. But, cars don’t reproduce or repair themselves and they don’t adapt, without the intervention of man.

Pure Sodium is a very dangerous metal; it reacts so violently with water that it explodes. Chlorine is a very dangerous element; it is a greedy chemical that wants to bind with anything it can. It is difficult to store because it is so reactive. When it is free it can cause burns and creates noxious compounds. These to chemical elements are very energetic and when they meet each other they combine in a reaction that consumes energy form the atoms and creates a lot of heat (the energy comes from the change in the state of the electrons and can’t be discussed without an understanding of Quantum Mechanics). The product of this reaction is salt, the most common chemical compound found on the surface of the earth. However, salt is salt, it can form into many compounds, and dissolve in water, but it is still a simple mineral. The reaction to form salt rips other chemical compounds apart creating waste; it forms in crystals, which are a form of cells and salt crystals can grow with additional deposits. But, salt can’t adapt or improve itself. It will always be some form of salt; the chemicals in it can change, but each variety of salt is the same as any other sample of that variety. However, with the introduction of other chemicals salt can seem to adapt and even evolve. But, salt is static. You can give it any stimulus and unless you try to change the actual structure it won’t respond.

A tree is alive; it needs fuel, it generates waste, it grows and it reproduces. But, trees don’t walk, and don’t think. They don’t feel pain and are not intelligent. However in spring when the trees blossom and spread their foliage they create seeds and show all the signs of life. Trees consume energy, as the leaves absorb light they use carbon dioxide to generate sugar with oxygen as its waste product. They have a cellular structure, they respond to stimuli (light), and they can adapt and evolve. There is no doubt a tree is alive, but it is a pretty passive form of life.

Then there are viruses. Viruses cannot reproduce; they need to hijack another cell to do that. Once they are in charge of that cell though they can reproduce themselves, consume energy, generate waste, they grow, they adapt and evolve. They also respond to stimuli like medications, the heat generated by a body with a fever. So is a virus alive or not? The best answer is that by itself a virus is not alive, and it will remain unalive until it hijacks a cell. Then it becomes a life form.

Computers and their cousins robots can seem to be alive. The computer consumes electrical energy and generates waste heat. Their components give them a cellular structure, while the keyboard and mouse provide stimuli to operate it. But, computers, by themselves, cannot adapt, grow or reproduce.

The computer itself can’t grow, reproduce, or adapt; but it’s data can. This data can reproduce itself, it consumes energy to make and maintain it, it can grow, it can respond to stimuli, it has a cellular structure and it can adapt, change and evolve. Even bogus or waste data can be created. So does that make a computer data a life form? Well the data itself has to be put into a program to do anything; otherwise it is just varying magnetic fields (or varying reflective qualities of light for DVDs and CDs). By itself the data can’t do anything.

The data can reproduce, but the computer can’t. The data can evolve, adapt and change, but without the computer it can’t do anything. The data can grow, but the computer itself cannot grow. Without ALL the key factors of life a computer is not alive. It seems to fulfill the definition of life, but it needs for both parts to function and by themselves they are not alive. A computer and its data are like a virus and a cell. If one is missing the other then they are not alive, but to be alive at least one part of the mix has to be alive. You can take all the components of life, or all the parts that make up an animal and do anything you want to them, but you still won’t create a life form. Every life form can do just that though, so what is going on here? There is some missing factor that creates a life form. I can’t tell you what it is, but you need something extra. A religious person might call it a soul, another person might call it will. I would like to hear what you or you class thinks about this. Because, if we ever find that missing ingredient, that little spark of life, then humans can become gods.

The equation of an organic life form is a complex one, with energy as only one factor. Without ALL the other factors then the item in question is not alive. All of the examples I described above consume energy, but by itself the tree is the only one that is a life form. Taking energy as the only factor in a life form is like expecting a computer to work with one of its vital parts missing. You also need that certain something, that unknown ingredient that makes something alive.

Answer 2

Internal combustion engines and electric motors also use energy but they're not alive so this is a poor criterion for determining life.

A far better definition of life is a system which increases in complexity over time. Non life systems tend to decrease in complexity over time.

Answer 3

I have a great website for you since you are stuck on this bio question( IT'S CALLED THE MAD SCIENTIST NETWORK AND TO LOG ON TO IT GO TO )
www.madsci.org it bills itself as the laboratory that never sleeps. has answers to 36,000 commonly asked questions maybe you can find your answer there. Good luck.