Which of the following structures prevents the entry of food into the trachea during swallowing?
A. Glottis
B. Epiglottis
C. Tongue
D. Uvula
Answer: Option B
Solution (By JKSSB Mock Tests)
The epiglottis is a cartilaginous flap that covers the glottis (the opening into the larynx and trachea) during swallowing, directing food and liquid into the esophagus. The tongue moves food, the glottis is the opening itself, and the uvula is a soft tissue hanging at the back of the palate that assists in speech and prevents nasal regurgitation.
Explanation:
Glaucoma is a group of eye diseases that result in damage to the optic nerve, often associated with elevated intraocular pressure. It can lead to permanent vision loss if untreated. Cataract is lens clouding, conjunctivitis inflammation of the conjunctiva, retinal detachment is separation of the retina.
Explanation:
Petrified fossils (permineralization) form when dissolved minerals infiltrate the porous tissues of dead organisms and harden, turning the remains into stone while preserving internal structure. Mold and cast fossils are impressions, trace fossils are tracks or burrows. Petrified wood is a common example.
Explanation:
Mitochondria are double-membrane organelles with circular DNA (like prokaryotes) and 70S ribosomes, supporting the endosymbiotic origin. They are absent in prokaryotes. They are the site of aerobic respiration. The matrix contains enzymes for Krebs cycle. The inner membrane forms cristae, housing electron transport chain and ATP synthase.
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