Lifes

Without genetic, variation,  there could be no evolution.  Imagine that all individuals in a special had the exact same set of genes. Their offspring would all be the same, and would all have an equal chance of survival.  It's the variations in genes,  which are expressed as variations in traits that cause some individuals to thrive and others to fall prey to predators and other threats in their environment.  Consider the finch,  the bird that famously caught darwin's attention on his voyage to the Galapagos islands.  Finches have different kinds of beaks,  each one best suited for a particular task. Some beaks are best for cracking hard nuts,  others for reaching into tight spaces,  still others for eating small seeds. The type of beak that an individual finch has will affect that finch's ability to survive in a given environment . If there is drought that kills the plant that produce small seeds,  the finches with large,  st...

Drugs are substances that alter or change the normal function of the mind or body. Drug if used continuously permanently changes the chemistry and neural structures of the brain as a result normal functioning without the drug is made nearly impossible.  This uncontrollable desire for drugs is known as addiction.  Generally people get drug addicted when they uses-chemicals which relax them relive pain,  or heighten their awareness. If it makes feel good,  they want more. Without the drug,  they feel tense,  tortured,  and generally miserable. Enjoyment of a drug's is the mental aspect of addiction. The loss of control,  the inability to manage when or how much it is used,  is the most obvious indicator,  of addiction.  Sometime people suffer from emotional addiction and they believe that they need drugs in order to achieve some goals or they-use drugs to avoid feelings of depression or anxiety (common symptoms of mental illness). Add...

The name vitamin was originally vitamine because the first one that was found was an amine,  hence the name vital amine or vitamine. Subsequent studies of other such substance showed taht they were not all amine. So,  the "e" was dropped. Vitamins are organic compounds that can not be synthesized by an organsim but are very essential for the maintenance of normal metabolism and therfore must be included in the diet. The absence or deficiency of vitamins in diet results in various diseases. Carbohydrates,  fats and proteins are the three major classes of foods. To remin healthy we must take in relatively large amount of these substances.  They are not however , the only nutrients we require.  Some of our needs are satisfied only by vitamins and minerals.  Type of vitamins Vitamin A : Vitamin A may be obtained from green vegetables and fruits , fish liver oil,  eggs,  butter,  cheese etc. Vitamin A is not found in plants as such. It is ...

Salts have many different uses,  ranging from household to big industries.  Many salts,  like sodium chloride , are necessary for life itself. Calcium phosphate is the  main ingredient of our bones. Some salts,  like calcium sulphate dihydrates (CaSO4. 2H2O) are used in building materials. Some of the most common salts and their uses are given below. 1. Sodium carbonate (na2 CO3) :  is also called as soda ash or washing soda. It is used as a cleaning agent in laundries and as water softner. It is also used as raw material in glass manufacturing. It also finds applications in paper industry,  petroleum refining industry and leather industry. 2. Sodium hydrogen carbonate (sodium bicarbonate) NaHCO3 : is also called baking soda because it is used for baking cake and other confectionaries. It is used in medicine as antacid and also in tooth paste etc. 3. Copper sulphate (Cu SO4 5H2O) (blue vitriol): it is used for copper plating in electropalati...

Smoking can have major negative biological effects on the human body. Tobacco smoke contains,  tar, nicotine, carbon monoxide , nitrogen,  hydrogen cyanide and metals. The majority of the particulate matter that is inhaled by a smoker is composed of tar. Within a particle of tar,  there are many different harmful organic chemicals identified as carcinogens and tumor initiators.  Tar in its solid from is the component that stains the teeth and fingers of smokers. This substance also can stain and damage the lung tissue. Tar also increase the production of mucous and phlrgm. Bad social effects of smoking Breathing of smoke laden air by the nonsmokers is know as passive smoking. Majority of the nonsmokers are allergic to cigarette smoke as it produces irritation in their eyes and throats. They can also develop cancer by continuously living in an environment polluted with cigarette smoke. Moreover the people do not like the company of cigarette smokers due to bad s...

Process of urine formation can be divided in to three sub processes. 1. Pressure Filtration Arterial blood comes to the glomerulus with pressure exerted by the pumping of blood by the heart.  This blood while passing through glomerulus is filtered into Bowman's capsule. Blood is filtered here because walls of the glomerulus are porous,  and the fraction of the blood pressure reaching here provides the filtration pressure.  This filtrate collected in glomerulus is called as glomerular filtrate. Every thing which is smaller than the pores of the glomerulus is filtered out of the blood. Generally blood cells and plasma proteins are not filtered out whereas water and dissolved salts,  sugar,  medicines and nitrogenous wastes are filtered out of the glomerulus into the Bowmann's capsule. From here they enter the next part the renal tubule. As many useful substance such as glucose,  amino acids,  salts etc are still present in Bowmann's filtrate in aqueous...

Acid rain is an extremely destructive from of pollution,  and the environment suffers from its effects.  Forests,  trees,  lakes,  animals,  and plants suffer from acid rain. Acid rain can make trees lose their leaves.  Trees can also suffer from stunted growth ; and have damaged bark. The soil poisons the tree with toxic substances that the rain has deposited into it. Lakes are also damaged by acid rain. Fish die off, and that removes the main source of food for birds. Acid rain can even kill fish before they are born. 1 .  Green House Effect Atmospheric CO2 acts like the glass in a greenhouse,  allowing energy in the from of sunlight to enter but absorbing and holding that energy once It has been converted to heat. Several other "greenhouse gases" share this property including methane , and chlorofluorocarbons (CFCs) as well as water vapour.  Fossil-fuel consumption and forest fires are the principal causes of carbon dioxide build...

The unwise and unplanned destruction or removal of trees is called deforestation.  Forests are our most precious wealth. Our life is greatly dependent on forests. They are the natural factories for the production of oxygen. Forests provide green cover to the earth , a living place to wildlife,  fuel,  timber and recreation to man.  They control floods,  prevent formation of deserts and keep the air clean. Some of the reasons for deforestation are given below: a.   Urbanisation requires more land , thus forests are cut to build roads and houses etc. b.   More land is required for cultivation. c.    Trees are removed to develop pastures for grazing. d.    Wood is used both as timber or fuel wood. e.   Some plants are collected for their medicinal importance. f.   Some plants are removed to give us fibre. g.   Timber mafia cut the trees for easy cash.   Deforestation in tropical rainforests impact global e...

Antibiotics are the substance which are produced by one type of organism that adversely affects the other type of organism. Antibiotics are categorized as bactericidal if they kill the bacteria or bacteriostatic if they stop or inhibit the growth of bacteria.  In general,  the use or bactericidal antibiotics is preferred but many factors may also suit the use of a bacteriostatic antibiotic. When a bacteriostatic antibotic is used the duration of therapy must be sufficient to allow the body immune system to prepare proper defense against the invading bacteria. In case of virulent microorganisms or in case of weak immunity,  bactericidal antibiotics are preferred because they will omit the problem from its roots but they will affect the normal microorganisms in the body. In mild cases,  bacteriostatic antibiotics could be used because of their minor side effects. Antibiotics are also effective against fungal infections.  Amore general term "Anti infective" describ...

Apart from the nagative physical effects of drug use there are psychological and emotional effects that are equally as devastating. One of the areas that is almost universally damaged is a person's view of oneself,  their self-esteem. Self-esteem virtually never rises when drug use is induced;  it almost always sinks lower and lower. As a person's self-esteem decreases through drug use,  the nagative feeling of worthlessness,  hopelessness , shame and guilt increase.   Drug addicts : a menace for society This is often due to the fact that a person realizes deep down that drug use is a destructive thing to be doing,  yet they do it anyway.  This sets up a contradiction between internal values and actual actions taken. One of the most destructive things that drug use does is it interferes with a person's ability to from caring and honest: relationships. It also tends to destroy relationships that currently exits.  This is essentially due to th...