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Human genome
The human genome is the genome of Homo sapiens. It is made up of 23 chromosome pairs with a total of about 3 billion DNA base pairs. There are 24 distinct human chromosomes: 22 autosomal chromosomes, plus the sex-determining X and Y chromosomes. Chromosomes 1-22 are numbered roughly in order of decreasing size. Somatic cells usually have one copy of chromosomes 1-22 from each parent, plus an X chromosome from the mother, and either an X or Y chromosome from the father, for a total of 46. There are an estimated 20,000-25,000 human protein-coding genes. The estimate of the number of human genes has been repeatedly revised down from initial predictions of 100,000 or more as genome sequence quality and gene finding methods have improved, and could continue to drop further.
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Health & Medicine News
November 3, 2025
Nov. 3, 2025 — Duke-NUS scientists unveiled BrainSTEM, a revolutionary single-cell map that captures the full cellular diversity of the developing human brain. The project’s focus on dopamine neurons provides crucial insight for Parkinson’s treatment. Their ...
Nov. 3, 2025 — Scientists uncovered how the amino acid leucine enhances mitochondrial efficiency by preserving crucial proteins that drive energy production. By downregulating the protein SEL1L, leucine prevents unnecessary degradation and strengthens the cell’s ...
Nov. 3, 2025 — Penn State scientists uncovered an ancient bacterial defense where dormant viral DNA helps bacteria fight new viral threats. The enzyme PinQ flips bacterial genes to create protective proteins that block infection. Understanding this mechanism could ...
Nov. 3, 2025 — A team of scientists has developed a highly accurate blood test for Chronic Fatigue Syndrome. The test reads tiny DNA patterns that reveal the biological signature of the illness. For millions who’ve faced doubt and misdiagnosis, it’s a ...
Nov. 3, 2025 — Disrupted sleep patterns in Alzheimer’s disease may be more than a symptom—they could be a driving force. Researchers at Washington University found that the brain’s circadian rhythms are thrown off in key cell types, changing when hundreds of ...
Nov. 3, 2025 — Scientists have discovered that a “longevity gene” found in people who live beyond 100 can reverse heart aging in models of Progeria, a devastating disease that causes children to age rapidly. By introducing this supercentenarian gene into ...
Nov. 2, 2025 — Cognitive struggles are climbing across the U.S., especially among young and economically disadvantaged adults. Rates of self-reported cognitive disability nearly doubled in people under 40 between 2013 and 2023. Researchers suspect social and ...
Nov. 1, 2025 — Researchers discovered that altering the body’s natural rhythm can help protect the brain from Alzheimer’s damage. By turning off a circadian protein in mice, they raised NAD+ levels and reduced harmful tau buildup. The findings suggest that ...
Nov. 1, 2025 — New research from Australia overturns the old idea that exercise “uses up” heartbeats. It shows that fitter people actually use fewer total heartbeats each day thanks to their lower resting heart rates, even when accounting for workouts. ...
Nov. 1, 2025 — More screen time among children and teens is linked to higher risks of heart and metabolic problems, particularly when combined with insufficient sleep. Danish researchers discovered a measurable rise in cardiometabolic risk scores and a metabolic ...
Oct. 31, 2025 — People living in socially and economically disadvantaged neighborhoods may face higher dementia risks, according to new research from Wake Forest University. Scientists found biological signs of Alzheimer’s and vascular brain disease in those from ...
Oct. 31, 2025 — Scientists discovered that a blood molecule called CtBP2 may play a major role in how we age. It helps regulate metabolism and appears to link aging across the entire body. Lower levels are tied to poor health and faster aging, while higher levels ...
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Oct. 31, 2025 — Semaglutide appears to safeguard the heart even when patients lose little weight. In a massive international trial, heart attack and stroke risk dropped by 20% regardless of BMI. The benefit seems ...
Oct. 30, 2025 — Researchers in Japan have revealed how some gourds draw pollutants into their fruits. The secret lies in a protein that carries contaminants through the plant sap. By manipulating this protein’s ...
Oct. 30, 2025 — From mini-brains to spider-inspired gloves and wolf apple coatings, scientists are turning eerie-sounding experiments into real innovations that could revolutionize health and sustainability. ...
Oct. 30, 2025 — By electrically stimulating macrophages, scientists at Trinity College Dublin have found a way to calm inflammation and promote faster healing. The process turns these immune cells into ...
Oct. 30, 2025 — Researchers used supramolecular nanoparticles to repair the brain’s vascular system and reverse Alzheimer’s in mice. Instead of carrying drugs, the nanoparticles themselves triggered natural ...
Oct. 29, 2025 — Flatworms can rebuild themselves from just a small fragment, and now scientists know why. Their stem cells ignore nearby instructions and respond to long-distance signals from other tissues. This ...
Oct. 29, 2025 — People with gum disease may have higher levels of brain white matter damage, a new study finds. Researchers observed that participants with gum disease had significantly more white matter ...
Oct. 29, 2025 — Finnish scientists found that eicosapentaenoic acid (EPA) from fish oil impacts each person’s metabolism uniquely. Participants showed strong but short-lived increases in EPA levels, with ...
Oct. 29, 2025 — New research reveals that intelligence plays a key role in how well people process speech in noisy environments. The study compared neurotypical and neurodivergent individuals and found that ...
Oct. 29, 2025 — A team of scientists discovered a hidden antibiotic 100 times stronger than existing drugs against deadly superbugs like MRSA. The molecule had been overlooked for decades in a familiar bacterium. It ...