Introduction
Biology is the study of life and living organism, including their structure, function, evolution, distribution, identification and Taxonomy. General Science Biology is an important section in the various competitive exams primarily the recruitment exams (Banking, SSC, Railways, RRB ALP, RRB Group D,etc.) in India. This General Science Biology Quick Guide presents the basics and key points of various Biology topics.
- Aristotle is often called “the father of biology”.
- Leeuwenhoek invented a simple microscope and studied living cells.
- Alexander Flemming discovered Penicillin.
- Gregor Johann Mendel discovered principles of inheritance.
- Louis Pasteur proposed ‘Germ theory of disease. He also proposed pasteurization for sterilization.
- Robert Hooke assembled a compound microscope and discovered cells in cork.
- Charles Darwin is famous for the theory of Natural selection.
- Hippocrates is considered to be the “father of western medicine”.
- Edward Jenner is famous for creating the first effective vaccine for smallpox- (father of immunology)
- William Watson (1909) introduced the term Genetics.
- Watson and Crick gave the model of DNA.
- In 1866 Ernst Haeckel coined word “ecology”
- Camillo golgi discovered golgi body.
- Salim Ali known as the “birdman of India”
- Har Gobind Khorana is a biochemist who won the Nobel Prize in 1968 for demonstrating how the nucleotides in nucleic acids control the synthesis of proteins.
Concepts
Cells:
- All living organism are constituted of structural and functional units called cells.
- Robert Hook coined the term ‘cell’ in 1665.
- Cells are grouped into tissues, tissues into organ and organs into organ system.
- Smallest cells- Mycoplasmas.
- Largest isolated single cell- egg of an ostrich
- Prokaryotic is without nucleus.
- It is found in bacteria, blue green algae, mycoplasma.
- The eukaryotic cells with nucleus occur in all protists, fungi, plants and the animals.
- Cell wall is present in plants cell.
- Cell membrane is composed of lipids.
- The function of plasma membrane is the transport of the molecules across it.
- Ribosomes were first observed by Palade.
- Ribosomes are present only in grandular endoplasmic reticulum.
- Except mammalian RBC all living cells have ribosomes.
- Nucleus is centrally located spherical and largest component of all eukaryotic cell. Nucleolus is present in nucleus.
- Mitochondria are also called “Powerhouse of cells”. They are involved in energy generation
- Most acceptable classification was given by R. H. Whittaker (1969). These are Monera, protista, Fungi, Plantae, Animalia.
- Study of genes is known as genetics.
- Gene is a segment of DNA and basic unit of heredity. These are located on chromosomes.
- DNA is found in nucleus, and also found in mitochondria and chloroplast.
- It stands for deoxyribonucleic acid (DNA).
- It is double stranded.
- It consists of Nitrogenous bases-Adenine, Thymine, Cytosine or Guanine, 5-carbon sugar and a phosphate molecule
- RNA is single stranded. It consists of phosphate, ribose sugar, nitrogenous bases Adinine, Uracil, Cytosine, and Guanine.
- Mendel conducted cross hybridization experiments on green pea plant (Pisum sativum).
- Sudden change in the sequence of DNA is known as mutation.
- X and Y are the sex chromosomes which are responsible for the determination of sex. 46 chromosomes are present in human body cell. In which 22 pairs of these are autosomes & 23rd is sex chromosomes, i.e. x & y
Digestion of Food:
| Name of the Digestive Juice | Name of the Enzymes | Substrate | End product |
|---|---|---|---|
| Saliva | Ptyalin (Salivary amylase) | Starch | Maltose |
| Pancreatic juice | Amylopsin (pancreatic amylase) | Starch, Glycogen | Maltose and Glucose |
| Intestinal juice | Sucrase (invertase), Maltase, Lactase | Sucrose; Maltose, Lactose | Glucose and fructose, Glucose, and galactose |
| Gastric Juice | Pepsin, Rennin | Proteins, Casein | Proteoses and peptones, Calcium caseinate |
| Pancreatic Juice | Trypsin, Chymotrypsin, Carboxyl peptidases | Proteins, Peptides | Proteoses and Peptides Amino acid. |
| Intestinal juice | Amino peptidase, Dipeptidase | Peptides | Amino acids |
Vitamin Required by the Body:
| Vitamin | Chemical Name | Function in Body | Deficiency Disease | Sources |
|---|---|---|---|---|
| [latex]B_1[/latex] | Thiamine pyrophosphate | Part of coenzyme for respiration | Beri-beri: nerve and heart disorders | Found in whole grain cereals, etc. |
| [latex]B_2[/latex] | Riboflavin | Part of coenzyme FAD needed for respiration | Ariboflavinosis: skin and eye disorders | Milk, yogurt, etc |
| [latex]B_{12}[/latex] | Cyanocobalamin | Coenzyme needed for making red blood cells, etc. | Pernicious anaemia | Animal products etc |
| [latex]B_5[/latex] | Nicotinic acid (‘niacin’) | Part of coenzymes NAD, NADP used in respiration | Pellagra: skin, gut and nerve disorders | Widespread in foods. |
| C | Ascorbic acid | Not precisely known | Scurvy: degeneration of skin teeth and blood vessels. | Lemon, orange, etc. |
| A | Retinol | Visual pigment, rhodopsin | Xeropthalmia: ‘dry eyes | Milk, eggs, etc. |
| D | Cholecalciferol | Stimulates calcium absorption by small intestine, needed for proper bone growth | Rickets: bone deformity | Found in dairy products, etc. |
| E | Tocopherol | Not precisely known | Infertility | Found primarily in plant oils, green, leafy vegetables, etc |
| K | Phylloquinone | Involved in blood clotting | Possible haemorrage | Green, leafy vegetables, etc. |
Minerals Required by the Body:
| Minerals | Source | Function |
|---|---|---|
| Sodium (Na) | Table salt large amounts is present in processed foods, etc. | for proper fluid balance, etc |
| Chloride | Table salt, large amounts is present in processed foods, etc. | for proper fluid balance, etc. |
| Potassium | Meats, milk, etc | for proper fluid balance, etc |
| Calcium | Milk and milk products, etc | Important for healthy bones and teeth, etc |
| Phosphorus | Meat, fish, poultry, eggs, milk, processed foods | Important for healthy bones and teeth, etc. |
| Magnesium | Nuts and seeds; etc. | Found in bones, etc |
| Sulfur | Occurs in foods as part of protein, meats, etc. | Found in protein molecules. |
| Iron | Organ meats; etc. | found in red blood cells. |
| Iodine | Seafood, foods grown in iodine-rich soil, etc. | Found in thyroid hormone. |
- Marasmus is produced by a simultaneous deficiency of proteins and calories.
- Kwashiorkar is produced by protein deficiency
Respiratory System:
The organ system which aids in the process of respiration is called the Respiratory system.
Organs of Respiration in Animals:
Human Respiratory System:
| Respiratory Organ | Animals |
|---|---|
| Lungs | Mammals, Birds, Reptiles and Amphibians |
| Gills | Fish, Crabs, Tadpole larva of Frog |
| Skin | Earthworm, Leech, Amphibians |
| Trachea | Insects |
- Human respiratory system consists of external nostrils, nasal cavity, nasopharynx, larynx, trachea, bronchiole and lungs.
Circulatory System:
- These are of two types open circulatory system and closed circulatory system.
- Generally present in arthopods and molluscs.
- Annelids and chordates have a closed circulatory.
- The human heart beats at the rate of about 72-80 per minute in the resting condition.
- ECG stands for Electrocardiogram. It is the graphic record of electronic current produced by the excitation of cardiac muscles.
- It is process of removal of undigested wastes from the body.
- Kidney plays a major role in the elimination of water waste in the form of urine.
- Urine contains ammonia, urea, uric acid, etc.
Endocrine System: Hormones and their Action:
| S.No. | Endocrine gland | Hormone | Action |
|---|---|---|---|
| 1 | Pituitary (Master gland) | Growth hormones, Anti-diuretic hormone Adeno – Corticotrophic hormone | Regulates the growth of bone and tissue. Controls the amount of water reabsorbed by the water. Defending the body against physiological stress e.g. exposure to cold. Follicle stimulating hormone stimulates ovary to produce female hormone. |
| 2 | Pineal | Melatonin | Regulates, circadian and sexual cycle |
| 3 | Thyroid | Thyroxine | Regulates rate of growth and metabolism. Too little-over weight and sluggishness. Too much-thin and over active. |
| 4 | Thymus | Thymosin | Helps in production of lymphocytes |
| 5 | Adrenal | Cortisone | Aids in conversion of proteins to sugar, cortex of this gland produces the hormone. |
| 6 | Pancreas | Insulin | Regulates sugar metabolism. Too little insulin leads to high sugar level in blood and weakness (a condition called diabetes) |
| 7 | Ovary | Estrogen | Development of secondary sexual characters e.g. development of breasts in female. |
| 8 | Testis | Testosterone | Development of many masculine features such as growth of moustaches and beard. |
Common Heart Diseases:
Viral Diseases:
Protozoan Diseases:
Fungal Diseases in Human Beings:
- Coronary artery disease or Arthrosclerosis
- Angina (angina pectoris)
- Heart Failure (congestive heart failure)
- Asthma
- Bronchitis (Inflammation of the Bronchi)
- Epilepsy: Epilepsy is a condition where a person has recurrent seizures, abnormal discharge of electrical activity in the brain cells.
| Disease | Pathogen | Affected Organ | Symptom |
|---|---|---|---|
| Anthrax | Bacillus anthracis | Skin and intestine | Skinulcer, sore throat, nausea, fever, breathlessness |
| Cholera | Vibrio cholerae | Intestine | Vomiting, acute diarrhoea, muscular cramps, dehydration etc. |
| Diphtheria | Corynebacterium diphtheriae | Respiratory tract | Difficulty in respiration (mainly in child of age 2-5 yrs). |
| Leprosy or Hansen’s disease | Mycobacterium leprae | Chronic infection of skin and nerve | Ulcers, nodules, scaly scabs (the infected part of the body becomes senseless). |
| Plague (i) Bubonic plague (ii) Pneumonic plaque | Pasteurella, Yersinia pestis | Blood disease Lungs | High fever, weakness and haemorrhage which turn black. Haemorrhage of bronchi, lungs |
| Tetanus (lock jaw) | Clostridium tetani | Central nervous system | Painful contraction of neck and jaw muscles followed by paralysis of thoracic muscles. |
| Tuberculosis | Mycobacterium tuberculosis | Lungs | Repeated coughing, high fever. |
| Whooping cough or Pertussis | Bacillus pertussis | Respiratory system | Continuous coughing |
| Pneumonia | Diplococcus pneumoniae | Lungs | Sudden chill, chest pain, cough, high fever. |
| Typhoid | Salmonella typhi | intestine | High fever, diarrhoea and headache |
| Disease | Pathogen | Affected Part | Symptom |
|---|---|---|---|
| AIDS (Acquired Immuno Deficiency Syndrome) | Bacillus anthracisHIV (Human Immuno Deficiency Virus) | White blood cells | Weak immune system. |
| Chicken pox | Vericella virus | Whole body | High fever, reddish eruption on body |
| Small pox | Variola virus | Whole body | Difficulty in respiration (mainly in child of age 2-5 yrs).Light fever, eruption of blood on body |
| Dengue fever | RNA containing dengue virus | Whole body, particularly head, eyes and joints | High fever, backache, headache, retro-orbital pain behind the eye ball. |
| Hepatitis (Epidemic Jaundice) (i) Hepatitis - A (ii) Hepatitis - B | Hepatitis virus Hepatitis - A virus Hepatitis - B virus | Liver | Loss of appetite, nausea, whitish stool and jaundice. Not fatal Fatal |
| Herpes | Herpes virus | Skin | Swelling of skin. |
| Influenza (flu) | Influenza virus | Whole body | Inflammation of upper respiratory tract, nose throat and eyes. |
| Measles German | Rubella virus | Whole body | Loss of appetite, reddish eruption on the body |
| Polio or poliomyelitis | Polio virus | Throat, backbone and nerve | Fever, backbone and intestine wall cells are destroyed. It leads to paralysis. |
| Rabies (hydrophobia) | RNA virus called rabies virus | Nervous system | Encephalitis, fear of water, high fever, headache, spasm of throat and chest leading to death |
| Swine influenza (flu) | [latex]H_1N_1[/latex] flu virus | Whole body (muscles) | Headache, tiredness, sore throat, vomiting, breathing problems. |
| Disease | Pathogen (Causative agent) | Vector | Parts Affected and Symptoms |
|---|---|---|---|
| African trypanosomiasis | Trypanosoma gambienes | Tsetse fly (Glossina palpalis) | Blood and nervous tissue. Man feels sleepy, may cause death. |
| Amoebic dysentery (Amoebiasis) | Entamoeba histolytica | None, Infection by contamination | Colon (intestine). Develop loose motion with blood, pain in abdomen |
| Diarrhoea | Giardia | None, infection by contamination | Digestive system causes loose motions, vomitting |
| Filaria or elephantiasis | Wuchereria bancrofti | Culex mosquito | Swelling of legs, testes and other body parts |
| Kala azar or dumdum fever | Leishmania donovani | Sand flies (Phlebotomus) | Spleen and liver enlarge and high fever develops. |
| Malaria | Plasmodium sp. | Female Anopheles mosquito | Periodical attacks of high fever, pain in joints accompanied by chill, heavy perspiration and fast pulse. |
| Disease | Pathogen (fungi) | Symptoms |
|---|---|---|
| Asthma or aspergillosis | Aspergillus fumigatus | Obstruction in the functioning of lungs. |
| Baldness | Tinea capitis | Hair fall |
| Athlete’s foot | Tinea pedis | Skin disease, cracking of feet. |
| Ringworm | Tricophyton Verrucosum | Round red spot on skin |
| Scabies | Acarus scabiei | Skin itching and white spot on the skin. |
- Blood is a liquid connective tissue.
- Blood has a fluid matrix called plasma.
- Plasma is a pale coloured fluid which contributes 55% of blood volume. Plasma contains 90 to 92% of water.
- Blood corpuscles are of three types: Red blood corpuscles (RBCs), white blood corpuscles(WBCs) and Blood platelets.
- RBC’s are formed in the red bone-marrow, and lack nucleus.
- Life span of RBCs (Erythrocytes) is about 120 days.
- WBCs (Leueocytes) are responsible for immunity.
- WBCs are manufactured in bone marrow.
- Neutrophils and monocytes are phagocytic cells (destroy foreign bodies)
- Basophils are involved in inflammatory reactions.
- Eosinophils are associated with allergic reactions.
- Lymphocytes are responsible for immune response.
- Platelets (thrombocytes) are responsible for clotting of blood during accidents.
- For a healthy adult person the average systolic/diastolic pressure is 120/80 mm of Hg in arteries near heart.
- The Rh factor is a type of protein on the surface of red blood cells. Most people who have the Rh factor are Rh-positive. Those who do not have the Rh factor are Rh-negative.
- Karl Landsteiner (1900) discovered the blood group in human.
- There are four groups of blood A, B, AB and O.
- Universal Donor: ‘O’ blood group person can give blood to all the four blood groups (O, A, B, and AB).
- Universal Recipient: ‘AB’ blood group person can take blood from all the four groups (AB, A, B, O).
Vaccines and their Doses:
| Age | Vaccination | Dose |
|---|---|---|
| Birth to 12 months |
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| 8-24 months |
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| 9-15 months |
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| 5-6 years |
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| 10 years |
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| 16 years |
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Inventions
Vaccines and Inventors:
Medical Science Discoveries:
| Vaccine | Developed by | Country | Year |
|---|---|---|---|
| Small Pox | Edward Jenner | England | 1796 |
| Cholera | Louis Pasteur | France | 1880 |
| Diphtheria and Tetanus | Emil Adolf Von Behring and Shibasaburo Kitasato | Germany/Japan | 1891 |
| TB Vaccine | Albert Calmette and Camille Guerin | France | 1922 |
| Polio Vaccine | Jonas E. Salk | US | 1952 |
| Oral Polio Vaccine | Albert Bruce Sabin | US | 1955 |
| Measles Vaccine | John F. Enders, Thomas peeble | US | 1953 |
| Rabies Vaccine | Louis Pasteur | France | 1885 |
| Typhus Vaccine | Charles Nicolle | France | 1909 |
| Rubella Vaccine | Paul D.Parkman & Harry M. Meyer jr | 1966 | |
| Scurvy vaccine | James Lind | 1753 |
| Invention | Inventor | Year |
|---|---|---|
| Penicillin | Alexander Fleming (scotland) | 1928 |
| Anesthetic | William Morton | 1846 |
| Anthrax vaccine | Louis Pasteur | 1881 |
| Antiseptic | Joseph Lister (Scotland) | 1867 |
| Artificial heart | Denton Cooley | 1969 |
| Bacteria (discovered) | Anton van Leeuwenhoek | 1674 |
| Cholera and T.B. Germs | Robert Koch (Germany) | 1883 |
| Cholera vaccine | Louis Pasteur | 1880 |
| Contact lenses (glass) | Adolf Fick | 1887 |
| Corneal transplants | Eduard Zirm | 1905 |
| Cough drops | James Smith and sons | 1847 |
| Dental drill (motor-driven) | George Fellows Harrington | 1864 |
| Disposable syringe | Colin Murdoch | 1956 |
| DNA (structure discovered) | Frances Crick, James Watson and Rosalind Franklin | 1953 |
| Electrocardiograph | Willem Einthoven | 1903 |
| Gas mask | Garrett Augustus Morgan | 1912 |
| Genetics | Johann Gregor Mendel | 1865 |
| Insulin (discovery) | Frederick Banting and Charles Best | 1921 |
| Iron lung | Philip Drinker | 1929 |
| Microscope (compound) | Hans Janssen | 1590 |
| Morphine | Friedrich Wilhelm Adam Serturner | 1803 |
| Pacemaker (human) | Wilson Greatbatch | 1960 (first use) |
| Pasteurisation | Louis Pasteur | 1864 |
| Pathology | Giovanni Battista Morgagni | 1761 |
| Penicillin | Alexander Fleming | 1928 |
| Stethoscope | René Laënnec | 1819 |
| Thermometer (medical) | Thomas Allbutt | 1866 |
| X-rays | Wilhelm Roentgen | 1895 |