Biological Science

Biology (from Greek: βίος, bio, "life"; and λόγος, logos, "speech" lit. "to talk about life"), also referred to as the biological sciences, is the scientific study of life. Biology examines the structure, function, growth, origin, evolution, and distribution of living things. It classifies and describes organisms, their functions, how species come into existence, and the interactions they have with each other and with the natural environment. Four unifying principles form the foundation of modern biology: cell theory, evolution, genetics and homeostasis.

Biology as a separate science was developed in the nineteenth century, as scientists discovered that organisms shared fundamental characteristics. Biology is now a standard subject of instruction at schools and universities around the world, and over a million papers are published annually in a wide array of biology and medicine journals.

Most biological sciences are specialized disciplines. Traditionally, they are grouped by the type of organism being studied: botany, the study of plants; zoology, the study of animals; and microbiology, the study of microorganisms. The fields within biology are further divided based on the scale at which organisms are studied and the methods used to study them: biochemistry examines the fundamental chemistry of life; molecular biology studies the complex interactions of systems of biological molecules; cellular biology examines the basic building block of all life, the cell; physiology examines the physical and chemical functions of the tissues and organ systems of an organism; and ecology examines how various organisms and their environment interrelate.

Biochemistry

Biochemistry (fromGreek: βίος, bios, "life" and Egyptian kēme, "earth") is the study of the chemical processes in living organisms. It deals with the structure and function of cellular components, such as proteins, carbohydrates, lipids, nucleic acids, and other biomolecules. Chemical biology aims to answer many questions arising from biochemistry by using tools developed within chemical synthesis.
Although there are a vast number of different biomolecules, many are complex and large molecules (called polymers) that are composed of similar repeating subunits (called monomers). Each class of polymeric biomolecule has a different set of subunit types. For example, a protein is a polymer made up of 20 or more amino acids. Biochemistry studies the chemical properties of important biological molecules, like proteins, in particular the chemistry of enzyme-catalyzed reactions.
The biochemistry of cell metabolism and the endocrine system has been extensively described. Other areas of biochemistry include the genetic code (DNA, RNA), protein synthesis, cell membrane transport, and signal transduction.
This article only discusses terrestrial biochemistry (carbon- and water-based), as all the life forms we know are on Earth. Since life forms alive today are hypothesized by most to have descended from the same common ancestor, they have similar biochemistries, even for matters that seem to be essentially arbitrary, such as handedness of various biomolecules. It is unknown whether alternative biochemistries are possible or practical.

Ecology

Ecology (from Greek: οίκος, oikos, "household"; and λόγος, logos, "knowledge") is the scientific study of the distribution and abundance of life and the interactions between organisms and their environment. The environment of an organism includes physical properties, which can be described as the sum of local abiotic factors such as insolation (sunlight), climate, and geology, and biotic factors, which are other organisms that share its habitat.
The word "ecology" is often used more loosely in such terms as social ecology and deep ecology and in common parlance as a synonym for the natural environment or environmentalism. Likewise "ecologic" or "ecological" is often taken in the sense of environmentally friendly.
The term ecology or oekologie was coined by the German biologist Ernst Haeckel in 1866, when he defined it as "the comprehensive science of the relationship of the organism to the environment." Haeckel did not elaborate on the concept, and the first significant textbook on the subject (together with the first university course) was written by the Danish botanist, Eugenius Warming. For this early work, Warming is often identified as the founder of ecology.

Microbiologist

A microbiologist is a scientist who works in the field of biology. They typically hold either a Bachelor of Science degree or Doctoral degree concentrating in microbiology. Microbiologists can be known under different names depending on the field of microbiology they specialize in:

• Bacteriologists - work in the field of bacteriology and study bacteria.


• Environmental Microbiologists - work in the field of environmental microbiology and study microbial processes in the environment.


• Food Microbiologists - work in the food industry and study pathogenic microorganisms that cause foodborne illness and spoilage.


• Industrial Microbiologists - generally work in field of biotechnology and study microorganisms that produce useful products.


• Medical Microbiologists - medical practitioners (doctors) who have chosen to specialize in the diagnosis and treatment of microbial diseases in patients.


• Mycologists - work in the field of mycology and study fungi.


• Protozoologists - work in the field of protozoology and study protists.


• Virologists - work in the field of virology and study viruses


• Microbial Epidemiologists - study the role of microorganisms in health and illness.
  
  

Microbiology

Microbiology is the study of microorganisms, which are unicellular or cell-cluster microscopic organisms. This includes eukaryotes such as fungi and protists, and prokaryotes such as bacteria and certain algae. Viruses, though not strictly classed as living organisms, are also studied.Microbiology is a broad term which includes many branches like virology, mycology, parasitology and others. A person who specializes in the area of microbiology is a microbiologist.
Although much is now known in the field of microbiology, advances are being made regularly. We have probably only studied about 1% of all of the microbe species on Earth.Thus, despite the fact that over three hundred years have passed since the discovery of microbes, the field of microbiology could be said to be in its infancy relative to other biological disciplines such as zoology, botany and entomology.

History
Pre-Microbiology
The existence of microorganisms was hypothesized for many centuries before their actual discovery in the 17th century. The first theories on microorganisms was made by Roman scholar Marcus Terentius Varro in a book titled On Agriculture in which he warns against locating a homestead in the vicinity of swamps:
“
...and because there are bred certain minute creatures which cannot be seen by the eyes, which float in the air and enter the body through the mouth and nose and there cause serious diseases.
”
This passage seems to indicate that the ancients were aware of the possibility that diseases could be srpead by yet unseen organisms.
In The Canon of Medicine (1020), Abū Alī ibn Sīnā (Avicenna) stated that bodily secretion is contaminated by foul foreign earthly bodies before being infected.He also hypothesized on the contagious nature of tuberculosis and other infectious diseases, and used quarantine as a means of limiting the spread of contagious diseases.
When the Black Death bubonic plague reached al-Andalus in the 14th century, Ibn Khatima hypothesized that infectious diseases are caused by "minute bodies" which enter the human body and cause disease.
In 1546 Girolamo Fracastoro proposed that epidemic diseases were caused by transferable seedlike entities that could transmit infection by direct or indirect contact or even without contact over long distances.
All these early claims about the existence of microorganisms were speculative in nature and not based on any data or science. Microorganisms were neither proven, observed, and correctly and accurately described until the 17th century. The reason for this was that all these early inquiries lacked the most fundamental tool in order for microbiology and bacteriology to exist as a science, and that was the microscope.

Electromagnetic Radiation

Electromagnetic (EM) radiation, also called light even though it is not always visible, is a self-propagating wave in space with electric and magnetic components. These components oscillate at right angles to each other and to the direction of propagation, and are in phase with each other. Electromagnetic radiation is classified into types according to the frequency of the wave: these types include, in order of increasing frequency, radio waves, microwaves, terahertz radiation, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays.

Theory
Electromagnetic waves were first postulated by James Clerk Maxwell and subsequently confirmed by Heinrich Hertz. Maxwell derived a wave form of the electric and magnetic equations, revealing the wave-like nature of electric and magnetic fields, and their symmetry. Because the speed of EM waves predicted by the wave equation coincided with the measured speed of light, Maxwell concluded that light itself is an EM wave.
According to Maxwell's equations, a time-varying electric field generates a magnetic field and vice versa. Therefore, as an oscillating electric field generates an oscillating magnetic field, the magnetic field in turn generates an oscillating electric field, and so on. These oscillating fields together form an electromagnetic wave.
A quantum theory of the interaction between electromagnetic radiation and matter such as electrons is described by the theory of quantum electrodynamics.

X-Ray (unit of measure and exposure)

An X-ray (or Röntgen ray) is a form of electromagnetic radiation with a wavelength in the range of 10 to 0.01 nanometers, corresponding to frequencies in the range 30 PHz to 30 EHz. They are longer than Gamma rays but shorter than UV rays. X-rays are primarily used for diagnostic radiography and crystallography. X-rays are a form of ionizing radiation and as such can be dangerous. In many languages it is called Röntgen radiation after one of the first investigators of the X-rays, Wilhelm Conrad Rontgen.

Unit of measure and exposure
The rem is the traditional unit of dose equivalent. This describes the Energy delivered by γ or X-radiation (indirectly ionizing radiation) for humans. The SI counterpart is the sievert (Sv). One sievert is equal to 100 rem. Because the rem is a relatively large unit, typical equivalent dose is measured in millirem (mrem) - 1/1000 rem, or in microsievert (μSv) - 1/1000000 Sv -, whereby 1 mrem equals 10 μSv.
The average person living in the United States is exposed to approximately 150 mrem annually from background sources alone.
Reported dosage due to dental X-rays seems to vary significantly. Depending on the source, a typical dental X-ray of a human results in an exposure of perhaps, 3, 40, 300 or as many as 900 mrems (30 to 9,000 μSv).