जीव विज्ञान – Biology MCQ
जीव विज्ञान – कृषि/वन प्रवेश
Biology · Agriculture, Veterinary & Forestry Entrance · ८४० प्रश्न
८४० प्रश्न उपलब्ध। मोड छान्नुहोस्:
जीव विज्ञान: प्रश्न र उत्तर
सही लागेको विकल्पमा थिच्नुहोस्। सही भए हरियो, गलत भए रातो देखिन्छ; ३ सेकेन्डपछि सही उत्तर र व्याख्या देखिन्छ।
सही: ० / ०
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A mutation in which a purine is replaced by another purine (for example A by G) is called a:
सही उत्तर: ख) Transition
Transition is the substitution of a purine for a purine or a pyrimidine for a pyrimidine; transversion swaps a purine with a pyrimidine.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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The operon model of gene regulation in bacteria was proposed by:
सही उत्तर: ख) Jacob and Monod
Francois Jacob and Jacques Monod described the lac operon in 1961.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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The anticodon, which pairs with a codon on mRNA, is located on:
सही उत्तर: क) tRNA
Each tRNA carries an anticodon loop that base-pairs with the complementary mRNA codon.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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During DNA replication, the short RNA primer needed to start a new strand is synthesised by:
सही उत्तर: घ) Primase
Primase (an RNA polymerase) lays down a short RNA primer to which DNA polymerase adds nucleotides.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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In B-DNA, approximately how many base pairs make one complete turn of the helix?
सही उत्तर: ग) 10
One turn of B-DNA (pitch 3.4 nm) contains about 10 base pairs, each 0.34 nm apart.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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The double helix model of DNA was proposed in 1953 by:
सही उत्तर: ख) James Watson and Francis Crick
Watson and Crick proposed the double helix in 1953 using X-ray diffraction data of Franklin and Wilkins.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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Pellagra, characterised by dermatitis, diarrhoea and dementia, results from deficiency of:
सही उत्तर: घ) Niacin (vitamin B3)
Niacin deficiency causes pellagra, known for the '3 Ds'.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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Beriberi is a deficiency disease caused by lack of:
सही उत्तर: ख) Thiamine (vitamin B1)
Thiamine deficiency leads to beriberi, which affects the nervous and cardiovascular systems.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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Scurvy, with bleeding gums and poor wound healing, is caused by deficiency of:
सही उत्तर: ख) Vitamin C
Vitamin C (ascorbic acid) is needed for collagen formation; its deficiency causes scurvy.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
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Different molecular forms of an enzyme that catalyse the same reaction, such as the forms of lactate dehydrogenase, are called:
सही उत्तर: ग) Isozymes
Isozymes (isoenzymes) differ in structure but catalyse the same reaction; LDH has five isozymes.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
यी अभ्यास प्रश्न हुन्, आधिकारिक प्रश्न होइनन्। पाठ्यक्रम, विज्ञापन र नतिजाका लागि सम्बन्धित निकायको आधिकारिक वेबसाइट हेर्नुहोस्। उत्तरमा गल्ती भेटे प्रश्नमुनिको "टिप्पणी / गल्ती रिपोर्ट" मा लेख्नुहोस्।
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