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
-
The ability of a single plant cell to regenerate into a complete plant is called:
सही उत्तर: क) Totipotency
Totipotency of plant cells is the basis of plant tissue culture and micropropagation.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The antibiotic penicillin was first obtained from the fungus:
सही उत्तर: क) Penicillium notatum
Alexander Fleming discovered in 1928 that the mould Penicillium notatum inhibits growth of Staphylococcus; streptomycin comes from Streptomyces griseus.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
Diatomaceous earth is formed from the cell walls of diatoms, which are made mainly of:
सही उत्तर: ख) Silica
Diatom walls (frustules) are impregnated with silica, so they do not decay and accumulate as diatomaceous earth used in polishing and filtration.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The infective stage of Plasmodium that enters human blood through the bite of a female Anopheles mosquito is the:
सही उत्तर: ग) Sporozoite
Sporozoites from the mosquito's salivary glands are injected into human blood and first multiply in liver cells.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
Methanogens, which produce methane in the rumen of cattle and in biogas plants, belong to:
सही उत्तर: ख) Archaebacteria
Methanogens are archaebacteria living in anaerobic environments; they produce methane from CO2 and H2 or acetate.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
In Nostoc and Anabaena, nitrogen fixation takes place in specialised thick-walled cells called:
सही उत्तर: क) Heterocysts
Heterocysts lack oxygen-evolving photosystem II, giving the oxygen-sensitive nitrogenase a suitable environment for fixing nitrogen.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The Ti plasmid, widely used as a vector for genetic engineering of dicot plants, is obtained from:
सही उत्तर: क) Agrobacterium tumefaciens
Agrobacterium tumefaciens causes crown gall by transferring T-DNA of its tumour-inducing (Ti) plasmid into plant cells; disarmed Ti plasmids are used as vectors.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
In agarose gel electrophoresis, DNA fragments move towards the:
सही उत्तर: ख) Anode, because DNA is negatively charged
The phosphate backbone makes DNA negatively charged, so fragments migrate to the positive electrode (anode), smaller ones moving faster.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The system of binomial nomenclature was introduced by:
सही उत्तर: ख) Carolus Linnaeus
Carolus Linnaeus popularised naming each species with two words (genus + specific epithet), for example in Species Plantarum (1753).
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The theory that life originated on earth through chemical evolution of non-living molecules in a primitive reducing atmosphere was proposed by:
सही उत्तर: ग) Oparin and Haldane
A.I. Oparin and J.B.S. Haldane independently proposed that the first life arose from simple organic molecules formed in a reducing atmosphere.
💬 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।
नमस्ते! पाठ्यक्रम, सामान्य ज्ञान, भाषा परीक्षा वा कुनै प्रश्नको उत्तर बुझ्न सोध्नुहोस्।
AI ले गल्ती गर्न सक्छ। महत्वपूर्ण कुरा आधिकारिक स्रोतमा जाँच्नुहोस्।