माय सर्च इन माय सुब्जेक्ट इन नस १ बिओलोगिकल

PHILIP JOHN F. VERALLO- BSBA
Introduction to Biology
Electron micrograph showing transcription of ribosomal RNA (rRNA) genes in the developing egg cell of the spotted newt. Fibers extending in clusters are molecules of rRNA used in the construction of cell's ribosomes. The long filaments indicated by green arrow are DNA molecules coated with proteins. RNA molecules get longer as transcription proceeds to completion as indicated by the red arrow. (Courtesy of Oak Ridge National Laboratory , U.S. Department of Energy. Used with permission.)
Education development efforts for these introductory biology courses are one of many activities conducted by the HHMI Education Group at MIT. This group focuses on curriculum development work for creating teaching tools in undergraduate biology courses.
Course Description

The MIT Biology Department core courses, 7.012, 7.013, and 7.014, all cover the same core material, which includes the fundamental principles of biochemistry, genetics, molecular biology, and cell biology. Biological function at the molecular level is particularly emphasized and covers the structure and regulation of genes, as well as, the structure and synthesis of proteins, how these molecules are integrated into cells, and how these cells are integrated into multicellular systems and organisms. In addition, each version of the subject has its own distinctive material.
7.012 focuses on the exploration of current research in cell biology, immunology, neurobiology, genomics, and molecular medicine.
Acknowledgements
The study materials, problem sets, and quiz materials used during Fall 2004 for 7.012 include contributions from past instructors, teaching assistants, and other members of the MIT Biology Department affiliated with course #7.012. Since the following works have evolved over a period of many years, no single source can be attributed.
What is biology?
Biology - The study of living organisms and their vital processes. It is the science devoted living organisms both plants and animals. The term biology has been derived from two Greek words; bios=life, logos=thinking, discourse or knowledge. It is divided into two main branches, botany and zoology. Biology is the area of science that studies life and its processes

The word biology is derived from the Greek words /bios/ meaning /life/ and /logos/ meaning /study/ and is defined as the science of life and living organisms. An organism is a living entity consisting of one cell e.g. bacteria, or several cells e.g. animals, plants and fungi. Aspects of biological science range from the study of molecular mechanisms in cells, to the classification and behavior of organisms, how species evolve and interaction between ecosystems.
The study of biology can be divided into different disciplines –
• Ethnology
• Evolutionary Biology
• Physiology
• Genetics
• Molecular Biology
• Morphology
• Systematic
• Ecology
Biology often overlaps with other sciences; for example, biochemistry and toxicology with biology, chemistry, and medicine; biophysics with biology and physics; stratigraphy with biology and geography; astrobiology with biology and astronomy. Social sciences such as geography, philosophy, psychology and sociology can also interact with biology, for example, in administration of biological resources, developmental biology, biogeography, evolutionary psychology and ethics.
What is the importance of biology?
Biology is a natural science which studies living organisms and how they interact with each other and their environment. It examines the structure, function, growth, origin, evolution, and distribution of living things. Also, it classifies and describes organisms, their functions, and how species come into existence. 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:
1. biochemistry examines the fundamental chemistry of life;
2. molecular biology studies the complex interactions of systems of biological molecules;
3. cellular biology examines the basic building block of all life, the cell;
4. physiology examines the physical and chemical functions of the tissues and organ systems of an organism; and
5. ecology examines how various organisms and their environment interrelate.
another answer
is the science that studies living organisms. Prior to the nineteenth century, biology came under the general study of all natural objects called natural history. The term biology was first coined by Gottfried Reinhold Treviranus.[citation needed] It 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.[1]
Biology examines the structure, function, growth, origin, evolution, distribution and classification of all living things. Five unifying principles form the foundation of modern biology: cell theory, evolution, gene theory, energy, and homeostasis.
HISTORY OF BIOLOGY
Biology - The Study of Life
By Regina Bailey, About.com
anatomy
biology
characteristics of life
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What is biology? Simply put, it is the study of life -- life in all of its grandeur. From the very small algae to the very large elephant, life has a certain wonder about it. With that in mind, how do we know if something is living? Is a virus alive or dead? What are the characteristics of life? These are all very important questions with equally important answers. Characteristics of LifeLiving things include both the visible world of animals and plants, as well as the invisible world of bacteria. On a basic level, we can say that life is ordered. Organisms have an enormously complex organization. We're all familiar with the intricate systems of the basic unit of life, the cell.Life can also "work." No, not the daily employment variety, but living creatures can take in energy from the environment. This energy, in the form of food, is transformed to maintain metabolic processes and for survival.Life grows and develops. This means more than just getting larger in size. Living organisms also have the ability to rebuild and repair themselves when injured.Life can reproduce. Have you ever seen dirt reproduce? I don't think so. Life can only come from other living creatures. Life can respond. Think about the last time you accidentally stubbed your toe. Almost instantly, you flinched back in pain. Life is characterized by this response to stimuli.Finally, life can adapt and respond to the demands placed on it by the environment. There are three basic types of adaptations that can occur in higher organisms.
· Reversible changes occur as a response to changes in the environment. Let's say you live near sea level and you travel to a mountainous area. You may begin to experience difficulty breathing and an increase in heart rate as a result of the change in altitude. These symptoms go away when you go back down to sea level.
· Somatic changes occur as a result of prolonged changes in the environment. Using the previous example, if you were to stay in the mountainous area for a long time, you would notice that your heart rate would begin to slow down and you would begin to breath normally. Somatic changes are also reversible.




· The final type of adaptation is called genotypic (caused by mutation). These changes take place within the genetic makeup of the organism and are not reversible. An example would be the development of resistance to pesticides by insects and spiders.
In summary, life is organized, "works," grows, reproduces, responds to stimuli and adapts. These characteristics form the basis of the study of biology.Basic Principles of BiologyThe foundation of biology as it exists today is based on five basic principles. They are the cell theory, gene theory, evolution, homeostasis, and laws of thermodynamics.
· Cell Theory: all living organisms are composed of cells. The cell is the basic unit of life.
· Gene Theory: traits are inherited through gene transmission. Genes are located on chromosomes and consist of DNA.
· Evolution: any genetic change in a population that is inherited over several generations. These changes may be small or large, noticeable or not so noticeable.
· Homeostasis: ability to maintain a constant internal environment in response to environmental changes.
· Thermodynamics: energy is constant and energy transformation is not completely efficient.
Subdiciplines of BiologyThe field of biology is very broad in scope and can be divided into several disciplines. In the most general sense, these disciplines are categorized based on the type of organism studied. For example, zoology deals with animal studies, botany deals with plant studies, and microbiology is the study of microorganisms. These fields of studycanbe broken down further into several specializedsubdisciplines. Some of which include anatomy, cell biology, genetics, and physiology






CHARACTERISTICS OF LIVING THINGS

It is not always an easy thing to tell the difference between living, dead, and non-living things. Prior to the 1600's many people believed that nonliving things could spontaneously turn into living things. For example, it was believed that piles of straw could turn into mice. That is obviously not the case. There are some very general rules to follow when trying to decide if something is living, dead, or non-living. Listed here are the six rules used by scientists:
Living things are made of cells.
Living things obtain and use energy.
Living things grow and develop.
Living things reproduce.
Living things respond to their environment.
Living things adapt to their environment.
If something follows one or just a few of the rules listed above, it does not necessarily mean that it is living. To be considered alive, an object must exhibit all of the characteristics of living things. Sugar crystals growing on the bottom of a syrup container is a good example of a nonliving object that displays at least one criteria for living organisms.

Ontario Biomedical Inst.Professional development courses in Clinical Research, Bioinformaticswww.ontariobiomedical.comhttp://ourworld.compuserve.com/homepages/davidschutz/livingEnv/notescharacteristics.htm Characteristics of living things
1. All living things are made up of cells. Organisms may be Unicellular (made up of one cell or Multicellular (made up of many cells)
2. All living things must be able to reproduce. Required for the species but not for each individual. Two basic kinds of reproduction are
Sexual reproduction- two cells from different parents unite to form zygote (first cell of new organism)
Asexual reproduction- one parent gives rise to new individual (binary fission or budding for example)
3. A L T are based on a universal genetic code, generally DNA



4. A L T Grow and develop - to get larger and change, have a life cycle
5. A L T Obtain and use materials and energy
Transport- movement of materials into out of or within
Metabolism - Chemical reactions of the life processes
Ingestion - taking in materials
Digestion - breaking down large molecules into simpler usable substances
Respiration - Combining oxygen with the products of digestion to release energy
Excretion - ridding the organism of unusable and waste materials
Nutrients- substances an organism needs for Energy Growth repair or maintenance
Synthesis- Production of large molecules by combining smaller ones
Photosynthesis- Production of large molecules (which contain stored energy) from smaller molecules using the suns energy
6. ALT respond to their environment - leaves face the sun, birds may fly south
7. ALT Maintain and regulate (control) an internal balance
Homeostasis - process by which organisms keep their internal conditions relatively the same
8. ALT evolve or can change over generations in response to environmental changes
Individual organisms can't evolve, a species can over many generations
8 Steps To The Scientific Method:
The 8 steps to the scientific method must be followed if the young scientist wants to be successful. You should also make sure the problem the experiment is trying to solve is not too big (look around the site for various science fair project ideas you can use).
Summary of the Scientific Method:
#1: The student will need to identify the problem. This begins when the scientist narrows down the possible projects to one topic.
#2: The child will ask an appropriate question. The question should be very specific and at this point parents and teachers can assist the child.


#3: It’s time to develop the hypothesis. The hypothesis is an educated guess or prediction about how the experiment will turn out.
#4: The student will now do the experiment. This is when the young scientist will organize and conduct the experiment.
#5: Always keep good records of the experiment. Everything should be recorded.
#6: The experiment should be repeated. When the experiment is repeated the student can be sure that the results noted the first time were correct and precise.
8 steps to the scientific method #7: Now the results will be analyzed. The student will look at the facts, numbers or statistics and see if the data is the same as their hypothesis. Sometimes the results match the hypothesis and sometimes they do not. Either outcome is all right.
8 steps to the scientific method #8: The conclusion can now be developed. The student may find that the conclusion provides answers to the question asked in step #2. The conclusion may or may not prove the scientist’s hypothesis.
Another key element in the scientific method is the research that will need to be done. Interviews can be done as well as the reading of books, magazines and any other materials available.

Chemical Basis of Life

Terms to define:
atoms -
elements - pure substances
Ex:
molecules -
Ex:
compounds -
Ex:


Parts of an Atom:
1. nucleus -
2. protons -
3. neutrons -
4. electrons -
Atomic mass -
Atomic number -
ISOTOPES - All atoms of the same element possess the same number of protons and electrons, but they may vary in the # of neutrons in their nucleus. Atoms with the same atomic number but different atomic weights are called isotopes.
Some unstable isotopes release energy or "pieces" of their nucleus as they decompose. These unstable isotopes are called radioactive isotopes and can be used as a diagnostic tool and in cancer treatments (see Martini Applications Manual for more information).
CHEMICAL BOND FORMATION
Valence shells (or orbitals)
Maximum # electrons in the 1st shell =
Maximum # electrons in the 2nd shell =
Maximum # electrons in the 3rd shell =
An atom is considered stable or inert (chemically inactive) when its outermost shell is completely filled. Helium, with 2 electrons is an example.
Types of Chemical Bonds:
1. Ionic Bonds -
2. Covalent Bonds -
3. Hydrogen Bonds -
Types of Chemical Reactions:
1. Catabolism
2. Anabolism
3. Exchange

Also Reversible Reactions...

Two Basic Types of Compounds in Living Organisms:
1. Inorganic compounds
2. Organic compounds
Examples and Properties of Inorganic compounds:
A. Gases
1. Oxygen
2. Carbon dioxide
B. Solutions (water: H2O)
1. Most essential and abundant compound in the body
2. Important solvent
3. Serves as a medium for chemical reactions
C. Inorganic Acids and Bases
1. Acids -
HCl -->
2. Bases -
NaOH -->
3. pH -
a. pH scale ranges from zero to fourteen
b. 0 - 6.9 =
c. 7.0 =
d. 7.1 - 14 =
4. Buffers
a. Resist very strong changes in pH
b. Release H+ when the pH starts to ____?
c. "Grabs" onto excess H+ when the pH starts to ____?


D. Inorganic salts (electrolytes)
Ex: Na+, K+, Ca2+, Mg2+, PO4 3-
Classes of Organic Compounds and Their Importance:
A. Carbohydrates (sugars, starch)
1. Monosaccharides
2. Disaccharides
3. Polysaccharides
4. Functions of carbohydrates
a. Fuel
b. Cell markers
c. Part of nucleotides
B. Lipids (fats)
1. Fatty acids
2. Triglycerides
3. Steroids
4. Phospholipids
5. Functions of lipids
a. Storage
b. Cell membranes
c. Steroid hormones
C. Proteins (polymers amino acids)
1. Structure of an amino acid (building blocks of proteins)
a. Amino group
b. R group

c. Carboxyl group
2. Functions
3. Enzyme Action
D. Nucleic Acids (DNA, RNA - for more information, see the Cell handout)
1. Building blocks = nucleotides
2. DNA -
3. RNA -
E. High-energy Compounds
Ex: ATP
STRUCTURE OF THE ATOM
Matter has mass and takes up space. Atoms are basic building blocks of matter, and cannot be chemically subdivided by ordinary means.
The word atom is derived from the Greek word atom which means indivisible. The Greeks concluded that matter could be broken down into particles to small to be seen. These particles were called atoms
Atoms are composed of three type of particles: protons, neutrons, and electron. Protons and neutrons are responsible for most of the atomic mass e.g in a 150 person 149 lbs, 15 oz are protons and neutrons while only 1 oz. is electrons. The mass of an electron is very small (9.108 X 10-28 grams).
Both the protons and neutrons reside in the nucleus. Protons have a postive (+) charge, neutrons have no charge --they are neutral. Electrons reside in orbitals around the nucleus. They have a negative charge (-).
It is the number of protons that determines the atomic number, e.g., H = 1. The number of protons in an element is constant (e.g., H=1, Ur=92) but neutron number may vary, so mass number (protons + neutrons) may vary.
The same element may contain varying numbers of neutrons; these forms of an element are called isotopes. The chemical properties of isotopes are the same, although the physical properties of some isotopes may be different. Some isotopes are radioactive-meaning they "radiate" energy as they decay to a more stable form, perhaps another element half-life: time required for half of the atoms of an element to decay into stable form. Another example is oxygen, with atomic number of 8 can have 8, 9, or 10 neutrons.



ELEMENTSAn element is a pure substance which cannot be broken down by further chemical techniques. These include heating, cooling, electrolysis and reacting with other chemicals. A sample of an element contains only one kind of atom in the sample.COMPOUNDSA compound is a pure substance composed of two or more different atoms chemically bonded to one another. A compound can be destroyed by chemical means. It might be broken down into simpler compounds, into its elements or a combination of the two.
A molecule is defined as a sufficiently stable, electrically neutral group of at least two atoms in a definite arrangement held together by very strong (covalent) chemical bonds.[1][2] Molecules are distinguished from polyatomic ions in this strict sense. In organic chemistry and biochemistry, the term molecule is used less strictly and also is applied to charged organic molecules and biomolecules.
In the kinetic theory of gases the term molecule is often used for any gaseous particle regardless of its composition.[3] According to this definition noble gas atoms are considered molecules despite the fact that they are composed of a single non-bonded atom.[4]
A molecule may consist of atoms of a single chemical element, as with oxygen (O2), or of different elements, as with water (H2O). Atoms and complexes connected by non-covalent bonds such as hydrogen bonds or ionic bonds are generally not considered single molecules.
No typical molecule can be defined for ionic crystals (salts) and covalent crystals (network solids), although these are often composed of repeating unit cells that extend either in a plane (such as in graphene) or three-dimensionally (such as in diamond or sodium chloride). The theme of repeated unit-cellular-structure also holds for most condensed phases with metallic bonding. In glasses (solids that exist in a vitreous disordered state), atoms may also be held together by chemical bonds without any definable molecule, but also without any of the regularity of repeating units that characterises crystals