Practice Biology MCQ Questions 26–43 out of 43. Free quiz with answers and explanations for UPSC, SSC, Railway exam preparation. Clear your general science biology section comprehensively with this high-yield biological science quiz. Engage with multiple choice questions covering human anatomy, vital organ systems, plant physiology, cell biology, genetics, infectious diseases, and vitamins to secure top ranks in SSC and railway exams.
Normal human somatic cells contain 23 pairs of chromosomes, leading to a total sum of 46 chromosomes. [Memory Trick: Human blueprints have 23 mom pieces + 23 dad pieces = 46 overall!]
Lysosomes are acidic compartments containing hydrolases that digest macromolecules, microbes, and debris. [Memory Trick: Lysosomes act like 'Lysol' spray, dissolving and cleaning up messy waste!]
Ethylene gas coordinates biochemical ripening pathways across plants. [Memory Trick: Fruits 'Ethyl'-ate themselves to grow soft and sweet!]
Yeast is a microscopic, single-celled fungus that converts simple carbohydrates into alcohol and CO2 by fermentation. [Memory Trick: Bakeries 'Y'ell for 'Y'east to raise soft bread!]
Glycolysis is the ancient pathway splitting sugar (glyco-) to yield ATP and pyruvate. [Memory Trick: 'Glyco' (sugar) + 'lysis' (splitting) = Glycolysis!]
Cellulose is an insoluble polysaccharide containing beta-glucose chains that provides structural rigidity. [Memory Trick: 'Cell'-ulose builds plant 'Cell' walls like protective woody fibers!]
Mycorrhizae enhance plant hydric and mineral absorption while receiving photosynthetic carbon products from hosts. [Memory Trick: 'Myco' (fungal) + 'rhiza' (root) = Mycorrhiza connection!]
The second cranial nerve (optic nerve) carries visual impulses from retina cells to brain processing centers. [Memory Trick: Cameras use 'Optic'-al lenses; eyes use 'Optic' nerves!]
Each polypeptide chain in hemoglobin holds a heme group featuring a central coordinate iron (Fe) ion. [Memory Trick: Steel-tough 'Iron' carries oxygen molecules through your blood veins!]
Adrenaline increases heart rate, dilates respiratory pathways, and mobilizes glycogen to ready muscles during danger. [Memory Trick: Ride down an 'Adrenaline' rollercoaster and feel the rush!]
A niche encompasses all biotic and abiotic resources utilized by a species, defining its job in the ecosystem. [Memory Trick: Find your comfortable 'Niche' to do your special work!]
Chitin is a modified nitrogenous polysaccharide providing strength and toughness to fungal structures and insect shells. [Memory Trick: Bug shells are made of hard 'Chi'-tin (sounds like tight-skin)!]
The cerebellum coordinates voluntary muscular sequences and governs equilibrium/stance control adjustments. [Memory Trick: A gymnast needs 'Cere-Bell-um' to walk along thin balance 'bells'!]
Guard cells swell or shrink by osmosis to dilate or shut stomatal apertures depending on moisture pressure. [Memory Trick: Tight 'Guard' cells stand duty as gatekeepers of gas gates!]
Osmosis is the spontaneous motion of water molecules to balance solute differences across barrier membranes. [Memory Trick: Water flows freely via 'O'-smosis to dilute 'O'-verloaded salt pools!]
Aedes aegypti mosquitoes carry Dengue, Zika, and Yellow Fever viruses, biting primarily in daylight hours. [Memory Trick: 'Ae'-des mosquitoes are daytime 'Ae'-rial attackers!]
Hemoglobin is the iron-containing oxygen transport metalloprotein in the red blood cells of all vertebrates. [Memory Trick: 'Hemo'-globin transports 'O2' throughout the global blood system!]
The larynx contains the vocal cords that vibrate to create sounds as air is pushed past them during exhalation. [Memory Trick: The 'L'-arynx sings sweet 'L'-yrics!]
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