In the NDA & NA (II) 2017 Exam, the question from general science covered key areas such as – disease, microbiology, biotechnology, etc. For the benefit of the NDA aspirants, Jagran Josh is providing geography questions, answers along with detailed explanation.
1. Golden rice is a genetically-modified crop plant where the incorporated gene is meant for biosynthesis of
(a) Omega-3 fatty acids
(b) Vitamin A
(c) Vitamin B
(d) Vitamin C
Ans. (b) Vitamin A
Golden rice is a variety of rice produced through genetic engineering to biosynthesize beta-carotene, a precursor of vitamin A, in the edible parts of rice. It is intended to produce a fortified food to be grown and consumed in areas with a shortage of dietary vitamin A, a deficiency which is estimated to kill 670,000 children under the age of 5 each year.
2. Which one of the following statements about microbes is not correct?
(a) They are used in sewage treatment plants.
(b) They are used in industrial fermenters for the production of beverages.
(c) No antibiotic has been obtained from any microbe.
(d) They are used to get many bioactive molecules for the treatment of diseases.
Ans. (c) No antibiotic has been obtained from any microbes.
The antibiotics being discovered were naturally produced antibiotics and were either produced by fungi, such as the antibiotic penicillin, or by soil bacteria, which can produce antibiotics including streptomycin and tetracycline.
3. Melanin is the natural pigment that gives colour to human skin, hair and the iris. It provides protection against
(a) Ultraviolet radiation
(b) Infrared radiation
(c) X-ray radiation
(d) Short wave radio radiation
Ans.(a) Ultraviolet radiation
Melanin helps to protect skin cell DNA from the damaging effects of ultraviolet (UV) radiation. UV radiation causes lesions or DNA damage to melanocytes, which are the skin cells that produce the skin pigment known as melanin. Melanin is a protective pigment in skin, blocking UV radiation from damaging DNA and potentially causing skin cancer.
4. Tendons through which muscles are connected to bones are tightly compacted bundles of which one of the following long fibrous protein?
Ans. (b) firbrin
Fibrin (also called Factor Ia) is a fibrous, non-globular protein involved in the clotting of blood. It is formed by the action of the protease thrombin on fibrinogen which causes it to polymerize. The polymerized fibrin together with platelets forms a hemostatic plug or clot over a wound site.
5. Which one of the following vitamins has a role in blood clotting?
(a) Vitamin A
(b) Vitamin D
(c) Vitamin E
(d) Vitamin K
Ans. (d) Vitamin K
Vitamin K is an essential nutrient necessary for responding to injuries – it regulates normal blood clotting. In addition, by assisting the transport of calcium throughout the body, Vitamin K may also be helpful for bone health: it may reduce bone loss, and decrease risk of bone fractures.
6. The term `Probiotic' is applied to
(a) Organic food
(d) Live microbial food supplement
Ans. (d) Live microbial food supplement
Probiotics are defined as live microorganisms that are believed to provide health benefits when consumed. The term probiotic is currently used to name ingested microorganisms associated with benefits for humans and animals. Probiotics are considered to be generally safe, but they may cause bacteria-host interactions and unwanted side effects in rare cases.
7. Which one of the following microbes causes acidification and curding of milk?
(a) Lactic Acid Bacillus
(b) Clostridium botulinum
(c) Vibrio cholerae
(d) Saccharomyces cerevisiae
Ans. (a) Lactic Acid Bacillus
Curds are a dairy product obtained by coagulating milk in a process called curdling. The coagulation can be caused by adding rennet or any edible acidic substance such as lemon juice or vinegar, and then allowing it to sit. The increased acidity causes the milk proteins (casein) to tangle into solid masses, or curds.
8. Intake of which one of the following food components should be minimized by patients having Gouty Arthritis due to elevated serum uric acid level?
(a) Food fibres
(b) Nucleic acids
Ans. (b) Nucleic acids
All meats, including organ meats, and seafood contain high levels of nucleic acids. Meat extracts and gravies are also notably high. Of these foods, organ meats such as liver have the most nuclei, and are therefore highest in nucleic acids.
9. Which one of the following is the scientific name of the causal organism of elephantiasis?
(a) Ascaris lumbricoides
(b) Culex pipiens
(c) Wuchereria bancrofti
(d) Fasciola hepatica
Ans. (c) Wuchereria bancrofti
W. bancrofti was named after physician Otto Wucherer and parasitologist Joseph Bancroft, both of whom extensively studied filarial infections like elephantiasis.
10. Who among the following shared the Nobel Prize in 1962 along with Francis Crick and James Watson for their discoveries concerning the molecular structure of nucleic acids?
(a) Erwin Chargaff
(b) Maurice Hugh Frederick Wilkins
(c) Rosalind Franklin
(d) Phoebus Levene
Ans. (b) Maurice Hugh Frederick Wilkins
The Nobel Prize in Physiology or Medicine 1962 was awarded jointly to Francis Harry Compton Crick, James Dewey Watson and Maurice Hugh Frederick Wilkins "for their discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material".
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