ScienceFriendly introductions to questions from across science. Start with something familiar, discover the explanation, and keep exploring.
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Are cleft chins rare? A true cleft chin, a visible Y-shaped groove in the chin bone and overlying soft tissue, appears in roughly 1 in 5 to 1 in 10 people depending on the population studied, so it is uncommon but not rare.
Read the story ↗Yes, you can be allergic to cats, and the culprit is a small protein rather than the hair itself. Roughly 10 to 20 percent of adults worldwide react to Fel d 1, a 38-kilodalton protein produced mainly in cat saliva and sebaceous glands.
Let's find outApproach-avoidance conflict is the psychological state in which one goal simultaneously pulls you toward it and pushes you away, and your behavior stalls until one force wins.
Let's find outKnuckles are joints, not bones. Specifically, each knuckle is a synovial joint — a gap where two bone ends meet inside a fluid-filled capsule — and in the fingers these are called metacarpophalangeal (MCP) and interphalangeal (IP) joints.
Let's find outGrapes are a low-to-moderate potassium fruit, not a high-potassium one.
Let's find outHot flashes are not a recognized early sign of pregnancy. The typical early-pregnancy heat sensation is a mild, sustained rise in basal body temperature of roughly 0.5 to 1.0 degrees Fahrenheit, driven by progesterone and lasting past the…
Let's find outAmoxicillin is a broad-spectrum aminopenicillin antibiotic that kills bacteria by binding penicillin-binding proteins and blocking cell-wall construction, at standard adult doses of 500 mg every 8 hours or 875 mg every 12 hours.
Let's find outNo, being in heat is not inherently painful for cats. Estrus is a hormonally driven reproductive phase, not a disease state, and the behavior owners interpret as suffering is courtship signaling driven by estrogen and rising progesterone.
Let's find outNo. Intrusive thoughts are not a sign of schizophrenia on their own — they are near-universal, with roughly 94% of adults reporting at least one unwanted intrusive thought in a given year, while schizophrenia affects about 0.3% of people…
Let's find outCoachwhip snakes are not venomous, and no antivenom exists because none is needed. They are non-venomous colubrids that kill by constriction and jaw pressure, not injected toxin.
Let's find outYes, dogwood berries are mildly poisonous to humans and pets, but the real risk depends on which dogwood species you are dealing with.
Let's find outAre baths good for a fever? A lukewarm bath can help a feverish person feel more comfortable, but it does not lower the body's internal core temperature and the evidence base for "fever baths" is weak.
Let's find outAre kiwis extinct? No. All five recognized kiwi species survive in the wild as of 2026, but every one of them is declining or at best stable, and none is safe.
Let's find outAmorphous sediment in urine refers to shapeless, granular material—mostly amorphous urates, phosphates, or drug precipitates—that forms when urine is concentrated or its pH shifts, and it is almost always harmless and clinically…
Let's find outFor most adults, pills are the better default for vitamins, because they deliver more accurate doses, allow more nutrients per serving, and cost far less per dose; gummies win only when swallowing difficulty or adherence is the real…
Let's find outNo, fleas are not invisible. An adult flea measures about 1.5 to 3.3 millimeters long, which is roughly the width of a grain of rice, and it is plainly visible to healthy human eyes at rest.
Let's find outBabies do not breathe air in the womb. The fetus receives all its oxygen through the placenta, which transfers oxygen from maternal blood across a membrane roughly 0.002 millimeters thick into fetal circulation.
Let's find outThe Arctic dandelion is a cold-adapted perennial of the genus Taraxacum that survives the high Arctic through a three-part mechanism: a deep taproot that stores energy below the frost line, a compressed rosette that traps heat within 2–3…
Let's find outCamel spiders are neither poisonous nor venomous. Solifugae, the order containing roughly 1,100 species sold in search results as "camel spiders," have no venom glands and no venom-delivering fangs.
Let's find outCrepe myrtle flowers are not toxic. The blossoms of *Lagerstroemia indica* and its hybrids contain no known toxins, and no human poisoning case has been documented from eating them.
Let's find outMost antidepressants raise serotonin or norepinephrine; only three drug classes reliably increase dopamine signaling in humans.
Let's find outYes, amino acids are good for you—they are the molecular building blocks your body uses to make proteins, enzymes, hormones, and neurotransmitters, and nine of the twenty standard amino acids must come from food because your body cannot…
Let's find outAmitriptyline is a tricyclic antidepressant sometimes prescribed off-label for cats, most often at 0.5 to 2 mg per pound (1 to 4 mg/kg) given once or twice daily by mouth.
Let's find outAnorectal health issues in the elderly are common, underreported, and largely mechanical: aging weakens the pelvic floor, thins the anal sphincter, slows colonic transit, and adds medications that harden or loosen stool.
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