Rubyna May L. Espiritu
Sir Adrian Guinto
November 15, 2012
The Characteristics of Life
There are many properties or the signs of life that the living organisms have. In the book of biology of Mrtinez and Nazareno, there are nine characteristics of life just said and those are :
a. Living things are highly organized and contain many complex chemical substances ;
b. Living things are made up of one or more cells, which are the smallest unit that can be said to be alive;
c. Living things use energy;
d. Living thins have definite form and a limited size;
e. Living things have definite life span;
f. Living things grow;
g. Living things respond to change in the environment;
h. Living things reproduce; and
i. Living things evolve or change over the period of time.
Redi and Pateur
In the book of Practical Biology (a modular approach), Redi diprove spontaneous generation when he placed the rotting meat in covered and uncovered jars, and noted that maggots formed onkly in the uncovered jar. The logic ? Well, we found out that maggots are baby flies and they come from the fly egg.
While Pasteur demonstrataed that broth boiled in a swan-neck flask protected from airbone microbes by curve in the flaks’s neck, which trapped including the microbes. But if he broke the swan-neck and waited a couple of days, microbe growth occurred. there was nothing “unfit” about boil broth or the air around it: both were perfectly suitable for bacterial growth.
Explanation on How Life Originated
Scientists agree that the conditions of early earth were different fromthose existing today. The primitive atmosphere was probably quite unlike the present atmosphere. It may have contain Mathane (CH4), Ammonia (CH3), Hydrogen (H2) and water vapor (H2O). rains probabaly fell on the barren rock and formed oceans. The planet was probabaly bombarded with energy in the form of ultraviolet and lighting.
In addition, the temparature was higher, and there are more sources of energy for producing chemical change.
Buffon and Lamarck
Georges Buffon was the one of the first to propose an idea other than divine creation. He found it striking that the earth and living things were all composed of the same type of the particles or element.
Jean Baptiste Lamarck from his studies of fossils and living organisms that evolution was driven by the sentiments interieurs or felt need of an organisms. Animals could change over generations if their environment dictated that they needed change to survive.
Theories of Evolution and Natural Selection
Evolution . That organism change based on the conditions present in their environment. It proposed by Lamarck and for addition, these characteristics resulting from these changes are passed on from one generation to the next.
It was Georges-Louis :Leclerc de Buffon w ho first studied and developed a concept that all living things are continuously changing.
Erasmus Darwi8n, Charle’s grandfather, also believed that species change through modification in a form which is passed onto their offspring.
Natural Selection is th e process of evolution an d it is based on the following principles:
1. There are rapid production of offspring on each generation.
2. Variations which are inherited exists in this population of organisms.
3. Characteristics which cause them to be fit in their environment have better chances of survival than those which are less fit. This capacity of organisms to survive and reproduce successfully is called natural selection.