11: The Vitamin containing cobalt is
(a) B1
(b) B2
(c) B6
(d) B12
12: Which organ is associated with the production of insulin in the human body ?
(a) Pancreas
(b) Liver
(c) Kidney
(d) Heart
13: Recently, LASIK (Laser Assisted In Situ Keratomileusis) procedure is being made popular for vision correction. Which one of the following statements in this context is not correct ?
(a) LASIK procedure is used to correct refractive errors of the eye
(b) It is a procedure that permanently changes the shapes of the cornea
(c) It reduces a person's dependence on glasses or contact lenses
(d) It is a procedure that can be done on the person of any age
Explanation:
LASIK or Lasik (laser-assisted in situ keratomileusis) is a type of refractive surgery for correcting myopia, hyperopia, and astigmatism. LASIK is performed by opthalmologists using a laser. This type of refractive eye surgery enables the cornea to become better by creating flaps on it making light easier to enter the eye and providing enhanced visual clarity.
Many young adults experience changes in their eyeglass and contact lens prescriptions in the teenage years. Vision stabilizes most often sometime in their 20s. So, the medical community has approved LASIK for age 18 and over. More importantly the person's eye prescription needs to be stable for at least one year prior to surgery. Patients in their 40s. or 50s who are considerting LASIK surgery to improve their vision might want to consider to be evaluated for implantable lenses as well.
The surveys determining patient satisfaction with LASIK have found most patients satisfied, with satisfaction range being 92 - 98 percent.
14: Consider the following:
1. Oxides of Hydrogen
2. Oxides of Nitrogen
3. Oxides of Sulphur
Which of the above causes/cause acid rain ?
(a) 1 and 2 only
(b) 2 and 3 only
(c) 3 only
(d) 1, 2 and 3
Explanation:
Acid rain is a rain or any other form of precipitation that is unusually acidic, i.e. elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals, and infrastructure through the process of wet deposition. Acid rain is caused by emissions of compounds of ammonium, carbon, nitrogen, and sulphur which react with the water molecules in the atmosphere to produce acids. Governments have made efforts since the 1970s to reduce the production of sulphur dioxide into the atmosphere with positive results. However, it can also be caused naturally by the splitting of nitrogen compounds by the energy produced by lightning strikes, or the release of sulphur dioxide into the atmosphere by volcano eruptions.
15: Acid precipitation is now regarded as a serious problem in some European and Asian countries. Its major cause or source is
(a) discharge of acidic effluents onto neutral or slightly alkaline land where the acidic components precipitate
(b) emissions of sulphur oxides and nitrogen oxides from thermal power plants and burning of fossil fuels; these oxides dissolve in atmospheric water vapour and fall back on earth as acid rain
(c) natural carbon dioxide released during respiration of living organisms dissolves in water, forming carbonic acid which is the chief contributor to acidity in rain water
(d) chloro-fluoro-carbons readily react with various chemicals near the earth's surface, producing acidic intermediates which cause acid precipitation