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July 21, 2026 · Biology

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Today's question

Why can a seabird's salt gland beat its kidney at handling seawater?

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Today's trivia answer

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The answer to “Why can a seabird's salt gland beat its kidney at handling seawater?” is Water-saving brine.

Why Water-saving brine is correct

Water-saving brine is the point. Bird and reptile salt glands can make hypertonic fluid, letting salt leave in a small water volume. That is why the organ matters beside the kidney: it turns seawater from a dehydration threat into a manageable salt-export problem.

Why the other choices are wrong

Extra oxygen storage

Extra oxygen storage solves a diving problem, not a salt problem. The clue is the output: brine. Salt glands make concentrated salty fluid, so ions leave with relatively little water instead of forcing the animal to flush salt out as dilute urine.

Faster food digestion

Faster food digestion is the wrong system. The gland receives salt from blood, not half-digested food. A useful comparison is other salt-gland animals: the same osmotic challenge can be routed through a compact head gland instead of digestion.

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Previous trivia questions of the day

Catch up on seven recent daily trivia questions with answers—use them for an adult quiz, a family warm-up, or a classroom prompt.

· Chemistry Around Us

Why does bread rise when baking?

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Answer: Yeast produces CO2 gas

Correct! Yeast is a living microorganism that eats sugars in the dough and produces carbon dioxide gas as waste. These CO2 bubbles get trapped in the gluten network, making the dough expand. Heat from baking makes the gas expand more and kills the yeast, setting the fluffy structure!

· Astronomy & Space

Why can't we see stars during the day?

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Answer: Sunlight is too bright

Correct! Stars are always in the sky, but during the day the Sun is so bright it overwhelms them. The Sun is much closer (93 million miles vs. Trillions of miles for other stars), so it appears millions of times brighter. Sunlight scatters in Earth's atmosphere, creating bright blue sky that drowns out the faint starlight. It's like trying to see a candle flame next to a spotlight - the candle is still lit, but you can't see it. At night, without the Sun's glare, stars become visible.

· Human Biology

Why can one-question bites beat a packed lesson when the idea is new?

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Answer: Working memory stays unjammed

Right. Working memory holds only a small amount of readily accessible information, while long-term memory can store richer schemas. Cognitive-load theory says instruction can fail when working memory is overloaded by unnecessary or too many elements. A single question can isolate one mechanism so the reader can actually operate on it.

· Human Biology

Why do we dream?

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Answer: Process emotions and memories

Correct! Dreams occur mainly during REM sleep when your brain is highly active. The brain processes emotions, consolidates memories, and makes connections between new and old information. The limbic system handles emotional content while the prefrontal cortex is less active, explaining dreams' illogical nature. Dreams may help solve problems and process experiences.

· Sports & Exercise

Why do tennis players grunt?

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Answer: Exhaling increases power output

Correct! Valsalva maneuver + power! Forceful exhalation (grunt) during shot: (1) Synchronizes breathing with strike—prevents breath-holding (Valsalva) which raises blood pressure dangerously. (2) Core engagement—abdominal muscles contract during exhalation, stabilizing trunk, transferring more force to shot. (3) Timing cue—coordinates movement. Studies show ~5% power increase! Some players habitually loud (Sharapova ~100 dB). Debate: does it distract opponents? Mostly biomechanical benefit—forced exhalation = better force production!

· Household Science

Why does leather need conditioning?

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Answer: Natural oils prevent drying

Correct! Leather is animal skin—it contains natural oils that keep it flexible. Over time, these oils evaporate, making leather dry, stiff, and prone to cracking. Leather conditioner replaces lost oils (like lanolin or mink oil), keeping fibers supple and preventing damage!

· Technology

Why did Ferrari give the 296 GTB a wide 120-degree V6 for its sound?

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Answer: Cleaner pulse spacing

Right. Ferrari's 120-degree V6 gives the 296 a symmetrical firing order, and equal-length tuned exhaust manifolds amplify the pressure waves. Regular pulse spacing keeps the harmonics cleaner as the engine climbs toward 8500 rpm. The 296 then uses a hot tube to bring that engine character into the cabin. The surprise is that a small V6 was engineered to behave acoustically like a more exotic engine.

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