1. Presence of which among the following salts in water causes “Blue Baby Syndrome”?
[A] Sulphates
[B] Chlorides
[C] Carbonates
[D] Nitrates
Show Answer
Correct Answer: D [Nitrates]
Notes:
Nitrates in drinking water can cause “blue baby syndrome”, which is a condition where infants have a reduced ability to carry oxygen in the blood (methemoglobinemia). The nitrates interfere with the oxygen carrying capacity of hemoglobin. This causes the skin to appear blue or purple. Nitrates in drinking water, often from agricultural runoff, are the cause of “blue baby syndrome”.
2. Which of the following bacteria forms an endosymbiotic nitrogen fixing association with roots of legumes that helps in Nitrogen Fixation?
[A] Clostridium
[B] Rhizobium
[C] Salmonella
[D] Staphylococcus
Show Answer
Correct Answer: B [Rhizobium]
Notes:
Rhizobium Found in roots of legumes, like Peas, grams, Pulses etc, where it fixes atmospheric nitrogen as ammonia, which is then converted into useful amino acid.
3. Least generative power is a feature of which among the following cells of Human Body?
[A] Brain
[B] Bones
[C] Skin
[D] Liver
Show Answer
Correct Answer: A [Brain]
Notes:
The human brain is the central organ of the human nervous system, and with the spinal cord makes up the central nervous system. It is considered to have the Least generative power.
4. What fraction of Human Blood is Plasma?
[A] 35%
[B] 45%
[C] 50%
[D] 55%
Show Answer
Correct Answer: D [55%]
Notes:
Blood plasma is the liquid component of whole blood, and makes up approximately 55% of the total blood volume. It is composed primarily of water with small amounts of minerals, salts, ions, nutrients, and proteins in solution. In whole blood, red blood cells, leukocytes, and platelets are suspended within the plasma.
5. The cultivation of which of the plants on wastelands has a potential to generate biofuel in large quantities?
[A] Jatropha curcas
[B] Copaifera langsdorffii
[C] Camelina sativa
[D] None of the above
Show Answer
Correct Answer: A [Jatropha curcas]
Notes:
The cultivation of Jatropha curcas on wastelands has a potential to generate biofuel in large quantities. It is a species of flowering plant in the spurge family called Euphorbiaceae, that is native to the American tropics, most likely in Mexico and Central America.
6. Which among the following correctly denotes Net Reproduction Rate?
[A] Average number of children that would be born to a woman over her lifetime
[B] Average number of children that would be born to a couple over their life time
[C] Birth Rate — Death rate
[D] The rate at which women are replaced by daughters who will have children
Show Answer
Correct Answer: D [The rate at which women are replaced by daughters who will have children]
Notes:
In population ecology and demography, the net reproduction rate is defined as the average number of offspring that would be born to a female if she passed through her fertility age. Or simply The rate at which women are replaced by daughters who will have children.
7. Non-vascular embryophytes are __:
[A] Pteridophytes
[B] Algae
[C] Bryophytes
[D] Gymnosperms
Show Answer
Correct Answer: C [Bryophytes]
Notes:
Bryophytes are an informal group consisting of three divisions of non-vascular land plants: the liverworts, hornworts and mosses. They play a vital role in regulating ecosystems because they provide an important buffer system for other plants.
8. Who among the following scientists is known for devising four criteria designed to establish a causal relationship between a causative microbe and a disease?
[A] Louis Pasteur
[B] Emil Behring
[C] Ivan Pavlov
[D] Robet Koch
Show Answer
Correct Answer: D [Robet Koch]
Notes:
Dr. Robert Koch was a German (Prussian) physician. In 1877 he isolated Bacillus anthracis (causative agent of Anthrax) . He also isolated Tuberculosis bacillus (Causative agent of TB) and Vibrio cholera (causative agent of Cholera). He is also known to develop Koch’s postulates, the four criteria designed to establish a causal relationship between a causative microbe and a disease. He was awarded the Nobel Prize in Physiology or Medicine for his tuberculosis findings in 1905.
9. How does calcium carbide ripen mangoes?
[A] It reacts with moisture and releases Ethylene
[B] It reacts with moisture and releases Acetaldehyde, which in turn releases ethylene
[C] It reacts with starch and releases Acetylene
[D] It reacts with moisture and releases Ethyne
Show Answer
Correct Answer: A [It reacts with moisture and releases Ethylene]
Notes:
For reasons of safe transportation of fruits, mangoes, bananas etc are picked before they ripen fully. Slightly green harvested mangoes are subjected to small containers of calcium carbide (CaC2) with a plastic covering. CaC2 reacts with the moisture in the air to release acetylene (or ethyne) gas as follows:
CaC2 + 2 H2O – C2H2 + Ca(OH)2
This option may give you slightest confusion if you don’t know the difference between Ethylene and Ethyne (Acetylene). Both are chemical substances produced by fruits to accelerate the normal process of fruit maturation — is a ripening hormone. Ethylene is C2H4 and has a carbon-carbon double bond. Acetylene is C2H2 and has a carbon-carbon triple bind. Acetylene contains more energy and burns hotter than ethylene. Ethylene is a gaseous compound , Acetylene is the chemical compound , which is the simplest alkyne and is also a hydrocarbon while Ethylene is the simplest alkene and classified as an unsaturated hydrocarbon. I hope you will never forget it now.
10. Which of the following artificial sweeteners is not broken down by the body and therefore it is non-caloric (no-calorie sweetener)?
[A] Aspartame
[B] Saccharin
[C] Sucralose
[D] Cyclamate
Show Answer
Correct Answer: C [Sucralose]
Notes:
Sucralose is an artificial sweetener. The majority of ingested sucralose is not broken down by the body and therefore it is non-caloric. Sucralose is approximately 600 times as sweet as sucrose (table sugar), twice as sweet as saccharin, and 3 times as sweet as aspartame. It is stable under heat and over a broad range of pH conditions. Therefore, it can be used in baking or in products that require a longer shelf life. The commercial success of sucralose-based products stems from its favorable comparison to other low-calorie sweeteners in terms of taste, stability, and safety. It is used because it is a no-calorie sweetener, and does not promote dental cavities, is safe for consumption by diabetics, and does not affect insulin levels.