DIFFERENCES FROM PAST PAPERS (2011)

1. Typhoons & Tornado

• Hurricane (also called typhoons) is a result of tropical disturbance on a water body, while a tornado is always formed on land.

• A tropical storm is labelled a hurricane if it takes place between Atlantic and Pacific Ocean, but the same storm is called a cyclone if it takes place in Indian Ocean.

• Though both have eyes or centre, the centre of a tornado can be huge, extending up to 20 miles in diameter, whereas the eye of a tornado is very small being only a few feet in diameter

• Hurricanes occur in the months of June to November, whereas Tornados occur in the months of April to June

• Tornados last for a few minutes or hours, whereas hurricanes can have a very long duration lasting for 2-3 weeks.

• Thunderstorms are effects of hurricanes, whereas they are the cause of a tornado

• Hurricanes can cause floods and tsunamis, whereas tornados spread epidemics and also contaminate water sources.

OR

A tornado is a violently rotating column of air extending from the base of a thunderstorm to the ground. In weather terms tornadoes are small, 50 yards wide on average and rarely exceeding a mile wide, though on rare occasions tornadoes up to 2.5 miles wide have occurred. Tornadoes are also short lived, lasting 10 minutes on average, though a few have lasted for over 3 hours. Tornadoes form from interactions of air currents in a thunderstorm.

Hurricanes and typhoons are essentially the same thing, only a hurricane is in the Atlantic ocean or north-eastern Pacific ocean while a typhoon is in the north western Pacific ocean. Both are tropical cyclones with winds of at least 74 mph. In addition to having strong winds these storms bring heavy rain and flooding. The average hurricane/ typhoon is about 300 miles wide and forms over the course of several days. Unlike tornadoes, which are generally as land-based event These systems develop from disorganized clusters of thunderstorms that feed of the moisture from warm ocean water, organize, and intensify.

2. Microscope & Telescope

Telescope and Microscope are two scientific instruments that serve their purposes differently. One of the main differences between a telescope and a microscope is that a telescope is used to view things that are far whereas a microscope is used to view things that are very near.

It is indeed true both the instruments are used to watch the minute details of the objects or things more clearly. Another important difference between telescope and microscope is that the focal length or the distance from the focal point to the lens is different in these two scientific instruments.
As a result of this the focal point in the case of a telescope may be at a far off place. On the other hand the focal point in the case of a microscope is just a fraction of an inch off.

The difference in the diameter of the lens used in the two instruments also matter a lot when it comes to the difference between them. The lens diameter or the aperture is much larger in a telescope. This is to ensure that the aperture allows tiny amount of natural light at the focal point.
On the other hand only artificial illumination is used in a microscope. The artificial illumination is made to fall at the focal point in a microscope. It is interesting to note that a telescope and a microscope differ from each other in terms of the curvature of the lens.

A microscope is used to look into smaller details like the structure of the cells and the unicellular organism. On the other hand larger objects that are very far off are the targets of a telescope. In short it can be said that a telescope is used to look into space. Magnification is the keyword in both the scientific instruments.

3. Ultrasonics & Infrasonic:

Ultrasonics:
The study of sound aves with high frequencies beyond the upper limit of human hearing or 20 thousand Hz. This technique is employed to locate a tumour, to scan a pregnant woman’s abdomen in order to produce a picture of foetus or to treat certain neurotically disorders.

Infrasonic:

These are the sound waves which have the frequencies lowest than the lowest limits of human hearing or 20 Hz.

OR

The sounds having frequency more than 20,000 hertz (Hz) are called ultrasonic or ultrasound and the sounds having frequency less than 20 Hz are called infrasonic or infrasound. Both of these sounds cannot be heard by human beings. The audible range for of hearing by human beings is 20 Hz to 20000 Hz.

4. Heavy & Hard Water (see 1999)

5. Isotope & Isomer (see 2010)

6. Antibodies & Antibiotics:

Antibodies:

Protein synthesized in the blood in response to the entry of foreign substances or organisms into the body. When the body get infected through virus or bacteria, specific antibody is produced which fights the disease.

Antibiotics:
These are substances which can stop the growth or destroy the bacteria or other microorganisms. The antibiotics are used to eliminate fatal diseases such as typhoid, plague and cholera etc.

OR

Antibodies
l They are what your body produces in response to the presence of antigens (bacterial or viral surface structures)
l They merely assist your white blood cells in identifying
l They also destroy and invade the unidentified microorganisms.

Antibiotics
l They are chemicals that work to destroy invading bacteria (usually by disrupting the outer cell wall and making it "leak" or by messing up the bacteria's metabolic processes. They are not produced by the body)
l Antibiotics can be antibacterial or antiviral. Antibacterial will only destroy bacteria and antiviral will only destroy viruses. There are not many antibiotics for viruses. Also a virus is not a eukaryote.

7. Antigen & Vaccine

Antigen:
A substance or organism that induces the production of an antibody. The antigen reacts with antibody. The antigen tissue proteins can cause problems in the transplant of organs by rejecting the introduction of new organ in the body.

An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as pollen or cells such as bacteria. The term originally came from antibody generator[1][2] and was a molecule that binds specifically to an antibody, but the term now also refers to any molecule or molecular fragment that can be bound by a major histocompatibility complex (MHC) and presented to a T-cell receptor. "Self" antigens are usually tolerated by the immune system; whereas "Non-self" antigens are identified as invaders and attacked by the immune system. self-antigens.

Vaccine:
The agent which is used to give immunity against various diseases. A vaccine consists of modified disease organisms such as live weakened viruses or dead that can induce the production of antibodies within the blood.
A vaccine is a biological preparation that improves immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing microorganism, and is often made from weakened or killed forms of the microbe or its toxins. The agent stimulates the body's immune system to recognize the agent as foreign, destroy it, and "remember" it, so that the immune system can more easily recognize and destroy any of these microorganisms that it later encounters.

Vaccines can be prophylactic (example: to prevent or ameliorate the effects of a future infection by any natural or "wild" pathogen), or therapeutic (e.g. vaccines against cancer are also being investigated; see cancer vaccine).