CHARACTERISTICS OF LIVING ORGANISMS

Cell



All living things are composed of one or more cells. Different types of cells have different "jobs" within the organism. Each life form begins from one cell, which then will split. These cells split, and so on. After this has happened several times, differentiation is undergone, when the cells change so that they are not the same thing anymore. Then they are used to begin to put together the final organism, some cells, for example, as the eyes, some as the heart, etc. The only arguable exception to this is viruses. They are not composed of cells, but are said to be "living."

Organization



Complex organization patterns are found in all living organisms. They arrange themselves on very small levels, grouping like things together. On larger levels, they become visible. This also has to do with differentiation, as the cells are organized in a manner that makes sense for the organism after they change to what they’ll be in the final organism.






Energy Use




All organisms use energy. The sum of the chemical energy they use is called metabolism. This energy is used to carry out everything they do. Autotrophs (plants) use energy from the sun for photosynthesis, to make their own ‘food’ (glucose). Heterotrophs (animals and humans) must ingest food for this purpose.






Homeostasis




All organisms have stable internal conditions which must be maintained in order to remain alive. These include temperature, water content, heartbeat, and other such things. In a way, this has to do with energy use, because a certain level of energy must be kept within the body at all times. For this, obviously, humans must then ingest food on a regular basis. Not all conditions are for the body to maintain itself; though most are.

Growth






All organisms grow and change. Cells divide to form new, identical cells. Differentiation happens, as well, when cells mutate into other types of cells, making a more complex organism. Organisms growing, changing, and becoming more complex is called development. Single-celled organisms do grow as well, but they will only become slightly larger – this is nearly unmeasurable.



Reproduction



All organisms reproduce in order to continue the species' life. This is combining genetic information (in sexual reproduction) or splitting into two organisms (in asexual reproduction) in order to create another of the same species. In sexual reproduction, the new organism will have some characteristics from the mother, and some from father. It may look like either of them, or it may not. In asexual reproduction, the new organism is an exact copy of the first. Sometimes, not every member of a species is able to reproduce. As long as others are (which we know they can, if they still exist today) then it does not threaten the species. (Except for mules, but don't worry about them, they are a bizarre anomoly.)


Response to stimuli:




A response can take many forms, from the contraction of a unicellular organism to external chemicals, to complex reactions involving all the senses of higher animals. A response is often expressed by motion, for example, the leaves of a plant turning toward the sun (phototropism) and by chemotaxis.



References:http://www.essortment.com/all/characteristics_rbrc.htm
http://en.wikipedia.org/wiki/Characteristics_of_living_things

Origin of Life

SPECIAL CREATION THEORY



Creationism, Special creation is a theological doctrine which asserts that the origin of the universe and all life in it suddenly sprang into being by unconditional fiat or divine decree. Roman Catholicism has defined "special creation" in a different way. In Catholic teaching, the doctrine of immediate or special creation refers to the origin of the human soul.
In the creationist use of the phrase, special creation adheres to a literal interpretation of Genesis creation, accepting it as an accurate historical account of creation of the universe in its present form over the course of six twenty-four hour days. Special creation was the dominant theory of life's origins in the western world from the 16th century until the middle of the 19th century when it was supplanted by evolutionary thought.[1][2]
Duane Gish of the Institute for Creation Research defined "special creation" as being creation using supernatural processes:
We do not know how the Creator created, [or] what processes He used, for He used processes which are not now operating anywhere in the natural universe. This is why we refer to creation as special creation. We cannot discover by scientific investigation anything about the creative processes used by the Creator.

SPONTANEOUS GENERATION



or Equivocal generation is an obsolete theory regarding the origin of life from inanimate matter, which held that this process was a commonplace and everyday occurrence, as distinguished from Univocal generation, or reproduction from parent(s). The theory was synthesized by Aristotle[1], who compiled and expanded the work of prior natural philosophers and the various ancient explanations of the appearance of organisms; it held sway for two millennia. It is generally accepted to have been ultimately disproven in the 19th Century by the experiments of Louis Pasteur, expanding upon the experiments of other scientists before him (such as Francesco Redi who had performed similar experiments in the 17th century). Ultimately, it was succeeded by germ theory and cell theory.
The disproof of ongoing spontaneous generation is no longer controversial, now that the life cycles of various life forms have been well documented. However, the question of abiogenesis, how living things originally arose from non-living material, remains relevant today.




Description

Spontaneous generation refers to both the supposed process by which life would systematically emerge from sources other than seeds, eggs or parents and to the theories which explained the apparent phenomenon. The first form is abiogenesis, in which life emerges from non-living matter. This should not be confused for the modern hypothesis of abiogenesis, in which life emerged once and diversified. The second version is heterogenesis (sometimes called xenogenesis), in which one form of life emerges from a different form.


ABIOGENESIS

In the natural sciences, abiogenesis, or origin of life, is the study of how life on Earth could have arisen from inanimate matter. It should not be confused with evolution, which is the study of how groups of living things change over time. Amino acids, often called "the building blocks of life", can form via natural chemical reactions unrelated to life, as demonstrated in the Miller-Urey experiment, which involved simulating the conditions of the early Earth. In all living things, these amino acids are organized into proteins, and the construction of these proteins is mediated by nucleic acids. Thus the question of how life on Earth originated is a question of how the first nucleic acids arose.
The first living things on Earth are thought to be single cell prokaryotes. The oldest ancient fossil microbe-like objects are dated to be 3.5 Ga (billion years old), just a few hundred million years younger than Earth itself. By 2.4 Ga, the ratio of stable isotopes of carbon, iron and sulfur shows the action of living things on inorganic minerals and sediments and molecular biomarkers indicate photosynthesis, demonstrating that life on Earth was widespread by this time. On the other hand, the exact sequence of chemical events that led to the first nucleic acids is not known. Several hypotheses about early life have been proposed, most notably the iron-sulfur world theory (metabolism without genetics) and the RNA world hypothesis (RNA life-forms).

EARLY CONDITIONS

Morse and MacKenzie[18] have suggested that oceans may have appeared first in the Hadean era, as soon as 200 Ma (million years) after the Earth was formed, in a hot 100 °C (212 °F) reducing environment, and that the pH of about 5.8 rose rapidly towards neutral. This has been supported by Wilde[1] who has pushed the date of the zircon crystals found in the metamorphosed quartzite of Mount Narryer in Western Australia, previously thought to be 4.1–4.2 Ga, to 4.404 Ga. This means that oceans and continental crust existed within 150 Ma of Earth's formation.
Despite this, the Hadean environment was one highly hazardous to life. Frequent collisions with large objects, up to 500 kilometres (310 mi) in diameter, would have been sufficient to vaporise the ocean within a few months of impact, with hot steam mixed with rock vapour leading to high altitude clouds completely covering the planet. After a few months the height of these clouds would have begun to decrease but the cloud base would still have been elevated for about the next thousand years. After that, it would have begun to rain at low altitude. For another two thousand years rains would slowly have drawn down the height of the clouds, returning the oceans to their original depth only 3,000 years after the impact event.



PANSPERMIA (Greek: πανσπερμία from πᾶς/πᾶν (pas/pan) "all") and σπέρμα (sperma) "seed") is the hypothesis that "seeds" of life exist already all over the Universe, that life on Earth may have originated through these "seeds", and that they may deliver or have delivered life to other habitable bodies.
The related but distinct idea of exogenesis (Gk. ἔξω (exo, outside) and γένεσις (genesis, origin)) is a more limited hypothesis that proposes life on Earth was transferred from elsewhere in the Universe but makes no prediction about how widespread it is. Because the term "panspermia" is more well-known, it tends to b e used in reference to what should strictly speaking be called exogenesis.
The first known mention of the term was in the writings of the 5th century BC Greek philosopher Anaxagoras [1] The panspermia hypothesis was dormant until 1743 when it appeared posthumously in the writings of Benoît de Maillet, who suggested that germs from space had fallen into the oceans and grown into fish and later amphibians, reptiles and then mammals. In the nineteenth century it was again revived in modern form by several scientists, including Jöns Jacob Berzelius (1834),[2] Kelvin (1871),[3] Hermann von Helmholtz (1879) and, somewhat later, by Svante Arrhenius (1903). Panspermia can be said to be either interstellar (between star systems) or interplanetary (between planets in the same star system). Mechanisms for panspermia include radiation pressure (Arrhenius) and lithopanspermia (microorganisms in rocks) (Kelvin).Directed panspermia from space to seed Earth or sent from Earth to seed other solar systems has also been proposed.

There is as yet no compelling evidence to support or contradict it, although the majority view holds that panspermia — especially in its interstellar form — is unlikely given the challenges of survival and transport in space. One new twist to the theory by engineer Thomas Dehel (2006) proposes that plasmoids ejected from the magnetosphere may move the few spores lifted from the Earth's atmosphere with sufficient speed to cross interstellar space to other systems before the spores can be destroyed.

Questions:
Which of these theories you believed most? and why?
How will you describe the different theories?

History of Zoology

Objectives:

1. Trace the history of zoology through making a concept map
2. Develop understanding in the beginning of zoology



History.



The study of zoology can be viewed as a series of efforts to analyze and classify animals. Attempts at classification as early as 400 BC are known from documents in the Hippocratic Collection. Aristotle, however, was the first to devise a system of classifying animals that recognized a basic unity of plan among diverse organisms; he arranged groups of animals according to mode of reproduction and habitat. Observing the development of such animals as the dogfish, chick, and octopus, he noted that general structures appear before specialized ones, and he also distinguished between asexual and sexual reproduction. His Historia Animalium contains accurate descriptions of extant animals of Greece and Asia Minor. He was also interested in form and structure and concluded that different animals can have similar embryological origins and that different structures can have similar functions.


In Roman times Pliny the Elder (WHOSE PHOTO IS AT THE SIDE) compiled four volumes on zoology in his 37-volume treatise called Historia Naturalis. Although widely read during the Middle Ages, they are little more than a collection of folklore, myth, and superstition. One of the more influential figures in the history of physiology, the Greek physician Galen, dissected farm animals, monkeys, and other mammals and described many features accurately, although some were wrongly applied to the human body. His misconceptions, especially with regard to the movement of blood, remained virtually unchanged for hundreds of years. In the 17th century, the English physician William Harvey established the true mechanism of blood circulation.

Until the Middle Ages, zoology was a conglomeration of folklore, superstition, misconception, and descriptions of animals, but during the 12th century it began to emerge as a science. Perhaps the most important naturalist of the era was the German scholar St. Albertus Magnus, who denied many of the superstitions associated with biology and reintroduced the work of Aristotle. The anatomical studies of Leonardo da Vinci were far in advance of the age. His dissections and comparisons of the structure of humans and other animals led him to important conclusions. He noted, for example, that the arrangement of joints and bones in the leg are similar in both horses and humans, thus grasping the concept of homology (the similarity of corresponding parts in different kinds of animals, suggesting a common grouping). The value of his work in anatomy was not recognized in his time. Instead, the Belgian physician Andreas Vesalius is considered the father of anatomy; he circulated his writings and established the principles of comparative anatomy. See ANATOMY
Classification dominated zoology throughout most of the 17th and 18th centuries. The Swedish botanist Carolus Linnaeus developed a system of nomenclature that is still used today—the binomial system of genus and species —and established taxonomy as a discipline. He followed the work of the English naturalist John Ray in relying upon the form of teeth and toes to differentiate mammals and upon beak shape to classify birds. Another leading systematist of this era was the French biologist Comte Georges Leclerc de Buffon. The study of comparative anatomy was extended by such men as Georges Cuvier, who devised a systematic organization of animals based on specimens sent to him from all over the world.Although the word cell was introduced in the 17th century by the English scientist Robert Hooke, it was not until 1839 that two Germans, Matthias Schleiden and Theodor Schwann, proved that the cell is the common structural unit of living things. The cell concept provided impetus for progress in embryology, founded by the Russian scientist Karl von Baer, and for the development by a Frenchman, Claude Bernard, of the study of animal physiology, including the concept of homeostasis (the stability of the body’s internal environment). See CELL,; PHYSIOLOGY,.The organization of scientific expeditions in the 18th and 19th centuries gave trained observers the opportunity to study plant and animal life throughout the world. The most famous expedition was the voyage of the Beagle in the early 1830s. During this voyage, Charles Darwin observed the plant and animal life of South America and Australia and developed his theory of evolution by natural selection. Although Darwin recognized the importance of heredity in understanding the evolutionary process, he was unaware of the work of a contemporary, the Austrian monk Gregor Mendel, who first formulated the concept of particulate hereditary factors—later called genes. Mendel’s work remained obscure


Activity:
Read the scripture on the history of zoology.
trace the history of zoology by making a concept map.

Reference: http://www.history.com/encyclopedia.do?articleId=226469